Converter steelmaking question bank (with answers)

Fill in the blanks (130 questions in total)

1. Industrial pure iron, steel and pig iron are all iron carbon alloys, but their carbon content is different.According to metallography, the iron carbon alloy with w [C] ≤ is industrial pure iron;W [C] ≥ is pig iron. The content of iron is generally 2% in other materials, but it is generally referred to as the content of iron in other materials. Answer: 0.0218%;2.11％
2. The parameters that molten iron has a great impact on smelting in front of the furnace are. Answer: molten iron quantity, temperature and composition
3. Converter end point control mainly includes and control. Answer: end point temperature;Endpoint component
4. According to its nature, slag can be divided into oxidation slag and. Answer: reducing slag
5. Converter temperature control mainly includes and control. Answer: process temperature;End point temperature
6. Oxygen supply intensity refers to the oxygen supply intensity per unit time. Answer: oxygen consumption per ton of steel
7. Refractories with or as the main component are called alkaline refractories. Answer: Cao;MgO
8. The slagging methods of converter smelting usually include. Answer: single slag method, double slag method and slag retention method
9. In the converter blowing process, the basic principle of gun position adjustment and control is to melt the slag, reduce carbon quickly, and increase temperature evenly. The gun operation should be less, accurate and fast. Answer: no splashing of early slags
10. For most types of steel, sulfur produces steel and phosphorus produces steel. Answer: hot and crisp;Cold crisp
11. The main factors affecting the refractoriness of converter final slag are MgO, and. Answer: TFE;alkalinity
12. Hot metal triple decarburization pretreatment can improve the decarburization speed of converter and realize steelmaking, but the disadvantage is to reduce. Answer: less slag;Scrap ratio
13. Adding an appropriate amount of aluminum into molten steel not only has the function of deoxidation, but also has the function of deoxidation. Answer: grain refinement
14. The corrosion of MgO-C brick is firstly caused by oxidation. Answer: carbon in brick
15. In the process of converter smelting, there are two ways of desulfurization: and. Answer: slag desulfurization;Gasification desulfurization
16. The common splash types of oxygen top blown converter are,, and. Answer: explosive spatter, foam slag splashing, metal spatter.
17. The oxygen lance nozzle is the energy converter of pressure and speed, that is, it converts the oxygen jet into oxygen jet. Answer: high voltage and low speed;Low voltage high speed
18. The Mach number at the outlet of the oxygen lance refers to the ratio of the oxygen lance head to the. Answer: gas velocity at the outlet;Speed of sound
19. The slag making system of converter shall follow the eight character policy. Answer: early melting, thorough melting, gluing and hanging
20. The main basis for determining a reasonable oxygen supply system is determined in an overall manner in terms of, and steel grades to be smelted. Answer: furnace capacity and hot metal composition
21. The main purpose of gun dropping at the end of converter blowing is to stabilize the flame and facilitate the judgment of the end point. Answer: composition and temperature of molten steel in uniform molten pool
22. The requirements of continuous casting for molten steel smelting in front of the furnace are,, and. Answer: composition, temperature and time
23. Firstly, the dissolution of lime is the infiltration of,, MnO, etc. from the surface to the inside. Answer: FeO, SiO2
24. The bottom air supply elements of compound blowing can be divided into and. Answer: tubular;Breathable brick type
25. When determining the loading amount of converter, appropriate and appropriate factors must be considered. Answer: furnace volume ratio;Bath depth
26. The relationship between slag and is represented by a graph, which is called the phase diagram of slag. Answer: melting point;form
27. Carbon mainly exists in steel in the form of carbon, which is the main element determining the strength of steel. Answer: carbide (Fe3C)
28. The dephosphorization reaction in steelmaking process is carried out at the interface between molten metal and slag.First [P] is oxidized to and then combined with to form stable calcium phosphate.The chemical reaction formula is:.
Answer: (P2O5);(CaO)；2[P]+5(FeO)+4(CaO)＝(4CaO.P2O5)+5[Fe]29.In Q235B, B represents. Answer: B indicates the quality level
30. Under the condition of a certain sulfur distribution coefficient, the sulfur content in steel depends on the sulfur content and. Answer: charge;Slag quantity
31. The principles for determining the blowing gun position of converter are.
Answer: early slagging, more dephosphorization and protection of furnace lining
32. The converter auxiliary gun probe has the function of measuring the liquid level height,, and of the converter molten pool. Answer: temperature measurement, sampling and oxygen determination
33. At present, the main types of electromagnetic stirring used in continuous casting are:. Answer: mold electromagnetic stirring (M-EMS), secondary cooling zone electromagnetic stirring (S-EMS), solidification end electromagnetic stirring (F-EMS)
34. Non metallic inclusions can be divided into:, and according to their deformation properties. Answer: brittle inclusion, plastic inclusion, spherical (or point) invariant inclusion
35. Non metallic inclusions can be divided into oxide inclusions, nitride inclusions, and phosphide inclusions according to their chemical composition. Answer: sulfide inclusion carbide inclusion
36. Calcium is a strong deoxidizing element. Adding calcium wire into liquid steel has a good effect on the,, and of liquid steel.
Answer: deoxidation, desulfurization and changing the morphology of inclusions
37. The best position of the blowing point at the bottom of the ladle is usually at the place away from the center of the ladle bottom in the direction of the radius of the ladle bottom. Answer: 1 / 2 ~ 2 / 3
38. Carbon inα-The solid solution formed in Fe is called, and its representative symbol is.Carbon inγ-The solid solution formed in Fe is called, and its representative is. Answer: ferrite;F；Austenite;A
39. In C-O reaction, when the carbon content in molten iron is high, it is a restrictive link, and when the carbon content in molten iron is low, it is a restrictive link. Answer: diffusion of oxygen;Diffusion of carbon
40. During the back blowing of the converter, the temperature of the molten pool can be increased, which is mainly due to the oxidation and heat release of iron in the molten pool.Therefore, it is a very passive method to increase the temperature of the molten pool and greatly increase the [O] in the molten pool. Answer: iron loss
41. Silicon can improve tensile strength and, especially. Answer: yield strength;Elastic limit
42. In order to improve the deep drawing performance of steel, the content of carbon and nitrogen in steel must be reduced;In order to improve the cold bending performance of steel, it is necessary to reduce the___________And reduce the content of. Answer: inclusions;S、P
43. Carbon is one of the main elements that determine the properties of steel. When the carbon content increases, the strength of steel increases and the weldability decreases. Answer: Mechanical
44. In general, dephosphorization is mainly carried out in smelting. Answer: early stage
45. Blowing loss and are the main causes of metal and heat loss. Answer: splash
46. There are generally two modes of oxygen transmission in oxygen top blown converter: indirect and indirect. Answer: direct oxygen transfer
47. In order to improve the effect of slag splashing and furnace protection, TFE in slag must be. Answer: reduce
48. The main purpose of ladle protection pouring is to avoid. Answer: secondary oxidation
49. The fundamental reason for slag drying is that the carbon oxygen reaction is intense and the slag is greatly reduced. Answer: FeO
50. Steelmakers should often check whether there is water leakage in the, hood, flue and furnace mouth. If so, they should stop blowing immediately. Answer: oxygen lance
51. The damage causes of furnace lining mainly include high-temperature heat flow, rapid cooling and heating, chemical erosion and so on.
Answer: the role of mechanical impact
52. Absorptivity of manganese and silicon in tapping alloying. Answer: greater than
53. The common point between early dephosphorization and late dephosphorization in converter steelmaking is. Answer: high FeO slag
54. For high-quality carbon steel, the content of phosphorus is required to be controlled below%. Answer: 0.035
55. It is the main dynamic property of slag. The over viscous slag removes phosphorus and sulfur slowly and reduces the yield of molten steel. The over dilute slag will aggravate the lining erosion. Answer: viscosity
56. The presence of sulfur in steel can improve the properties of steel. Answer: cutting
57. The thermodynamic conditions of dephosphorization are high alkalinity and appropriate low temperature. Answer: high iron oxide
58. The automatic control of oxygen top blown converter steelmaking process is divided into two categories: automatic control and dynamic control. Answer: Static Control
59. Whether the slag is “back dry” during blowing can be judged by observing the furnace mouth flame and. Answer: listen to the sound in the furnace
60. The main difference between rimmed steel and killed steel is.
Answer: different degrees of deoxidation
61. Mach number is the ratio of air velocity to local temperature. Answer: sound speed
62. The function of tapping slag retaining operation is. Answer: prevent phosphorus return
63. Active lime has the characteristics of,, and so on, so it is easy to melt and the slag forming speed is fast. Answer: high porosity, large specific surface and fine grains
64. The principle of adjusting and controlling the gun position in the early stage of blowing is to melt the slag early and well, so as to facilitate the removal of slag to the greatest extent. Answer: phosphorus
65. for the slag of the basic converter, the slag content is high, so foamed slag is easy to generate. Answer: FeO
66. Splashing is caused by explosive reaction and blocked discharge of carbon monoxide gas. Answer: carbon and oxygen
67. The cooling pipe is concentric with the water pipe in the middle layer. Answer: out
68. The operation of adding one or more alloying elements to the steel to meet the composition requirements of the finished steel is called. Answer: alloying
69. Explosive carbon oxygen reaction takes place in the molten pool of steelmaking, and the instantaneous generation of a large amount is the root cause of splashing. Answer: CO gas
70. There are three methods to control the end carbon content of molten steel: carbon pulling method, and carburizing method. Answer: gaola supplementary blowing method
71. The desulfurization efficiency of oxygen top blown converter steelmaking method is generally about, and the dephosphorization efficiency is generally about 70-90%. Answer: 40%
72. The time of adding alloy should not be too early or too late. Generally, the alloy should be added when 1 / 4 of the molten steel flows out and finished when 3 / 4 of the molten steel flows out.The alloy shall be added to the steel flow to facilitate melting and uniform stirring. Answer: impact site
73. Decarburization in oxygen top blown converter steelmaking mainly depends on and molten pool temperature. Answer: oxygen supply intensity
74. At present, there are two methods of flue gas purification, i.e. and unburned method. Answer: combustion method
75. The nature of slag is determined by its,, and. Answer: alkalinity;Oxidizability;Viscosity;
76. Al is added to killed steel to ensure and refine grain size. Answer: complete deoxidation
77. It is called the heart of continuous casting machine. Answer: crystallizer
78. The paper tube and for temperature measurement must be kept dry.
Answer: thermocouple head
79. In the blowing process, in order to increase the content of (FeO) in the slag, the oxygen lance height is often appropriate. In order to reduce the content of (FeO) in the slag, the low lance position operation is adopted.
Answer: improve
80. Generally speaking, iron and sulfur are regarded as harmful elements in ferroalloys. Answer: phosphorus
81. After starting a new furnace or making up the furnace, the slag of the first furnace shall be poured in time. It is necessary to inform the personnel around the platform in front of the furnace and the crown block to avoid, so as to prevent the falling off of the furnace lining, furnace collapse and large spray accident.
Answer: Tapping
82. In a sense, steelmaking is.
Answer: smelting slag
83. The heat source of converter steelmaking includes the physical heat of molten iron and two aspects. Answer: chemical heat
84. According to different deoxidizer adding methods and deoxidation mechanism, deoxidation methods are mainly divided into three categories: diffusion deoxidation, vacuum deoxidation.
Answer: precipitation deoxidation
85. At present, the main steelmaking methods in China are and electric furnace steelmaking. Answer: converter steelmaking process
86. It is the most abundant element in molten iron except iron. Answer: carbon 87The main components of raw dolomite are and magnesium carbonate. Answer: calcium carbonate 88When the end-point temperature of converter smelting is high, the residual manganese content of molten steel at the end-point. Answer: high
89. Molten pool depth refers to the distance from to the bottom of the converter when the converter molten pool is in a calm state. Answer: metal level
90. The general form of oxygen lance is.
Answer: porous Laval oxygen lance
91. Close containers and, etc. and do not mix with scrap steel into the furnace. Answer: Explosives
92. The slag retaining ball is added at the tapping stage and above the tapping port.
Answer: after
93. Sampling and temperature measurement shall be carried out during the molten steel in the furnace to ensure the representativeness of sampling and temperature measurement. Answer: calm
94. Carbon is the most abundant element in molten iron except iron, and the amount of carbon in molten iron is generally about. Answer: 4.00% 95Generally, CaO / SiO2 of high alkalinity slag should be above. Answer: 2.5
96. There are three operating systems of oxygen lance in oxygen top blown converter steelmaking process: constant pressure lance, constant pressure lance and variable pressure Lance. Answer: variable pressure gun
97. The temperature of molten iron entering the converter shall be above ℃.
Answer: 1250
98. There are three charging systems for oxygen top blown converter steelmaking process: fixed depth charging system, charging system and phased quantitative charging system.
Answer: quantitative
99. Due to the short blowing time of oxygen top blown converter, slag should be added in order to promote slagging. Answer: flux 100The specific gravity of slag retaining ball shall be the specific gravity of molten steel.
Answer: less than 101According to different pouring equipment, liquid steel pouring methods can be divided into two categories: and continuous casting. Answer: mold casting
102. The purpose of tapping slag retaining is to minimize the flow of converter into ladle. Answer: oxidized slag
103. Common deoxidizers include, ferrosilicon, silicon calcium alloy, aluminum, etc. Answer: Ferromanganese 104The main functions of ore are slagging, oxygen supply and. Answer: cooling 105The melting point of deoxidizer shall be at the temperature of molten steel. Answer: below
106. Hard blowing can increase FeO content in slag and decarbonization speed. Answer: reduce;rise
107. The calculation formula of binary basicity (R) of slag is. Answer: r = {Cao} / {SiO2}
108. Compared with top blowing, the reason for the significant increase of residual manganese in molten steel of combined blowing converter is. Answer: combined blowing reduces the oxygen content of molten steel
109. “60” in steel 60Si2MnA indicates yes. Answer: carbon content
110. In some cases, the presence of phosphorus is beneficial to steel, such as 09cupvre, which can improve the strength and hardness of steel and improve the properties of steel. Answer: corrosion resistance
111. N and Al can form, which inhibits the formation and precipitation of iron nitride. Answer: AlN
112. In order to make use of the after slab cutting, the slab hot delivery and continuous casting and rolling processes have been developed. Answer: physical sensible heat
113. The molecular formula of the low melting point compound formed after calcium treatment of aluminum killed molten steel is. Answer: 12CaO7Al2O3
114. Silicon oxidation is characterized by initial oxidation and complete oxidation, which belongs to reaction. Answer: fever
115. When determining the height of the oxygen lance, consideration should be given to. Answer: impact area, impact depth.
116. The main indexes of white slag in LF furnace are FeO < 1%. Answer: mn0 < 0.5%
117. Generally, the actual crystallization temperature is lower than the theoretical crystallization temperature, and the difference is expressed inΔT means, called. Answer: undercooling
118. Solidification of liquid steel can be divided into spontaneous nucleation and solidification. Answer: non spontaneous nucleation
119. The main harm of hydrogen to steel is that it will cause the following defects to steel:. Answer: hair crack, white spot, layered fracture
120. Adding a small amount of vanadium into the steel can produce fine and hard metal carbides or nitrides with the carbon or nitrogen of the steel, which can play a role in improving the, toughness, wear resistance, heat resistance, corrosion resistance and ductility of the steel. Answer: grain refinement, precipitation strengthening, strength
121. Carbon is one of the main elements that determine the properties of steel. When the carbon content increases, the strength of steel increases and the weldability decreases. Answer: Mechanical
122. The heat source of converter steelmaking includes the physical heat of molten iron and two aspects. Answer: chemical heat
123. The function of tapping slag retaining operation is. Answer: prevent phosphorus return
124. In general, dephosphorization is mainly carried out in smelting.
Answer: early stage
125. Blowing loss and are the main causes of metal and heat loss. Answer: splash
126. The time of adding alloy should not be too early or too late. Generally, the alloy should be added when 1 / 4 of the molten steel flows out and finished when 3 / 4 of the molten steel flows out.The alloy shall be added to the steel flow to facilitate melting and uniform stirring. Answer: impact site
127. The principle of adjusting and controlling the gun position in the early stage of blowing is to melt the slag early and well, so as to facilitate the removal of slag to the greatest extent. Answer: phosphorus
128. There are generally two modes of oxygen transfer in oxygen top blown converter: indirect and indirect. Answer: direct oxygen transfer
129. To improve the effect of slag splashing, TFE in slag must be. Answer: reduce
130. The main purpose of ladle protection pouring is to avoid. Answer: secondary oxidation

Explanation of terms (40 questions)

1. Hot metal pretreatment
Answer: it refers to the treatment process for desulfurization, desilication and dephosphorization before molten iron is mixed into the steelmaking furnace.
2. Cooling effect
Answer: the cooling effect refers to the heat consumed after each kg of coolant is added to the converter. It is commonly expressed in Q, and the unit is kJ / kg.
3. Converter calendar utilization factor
Answer: the qualified steel output produced by the converter per nominal ton per day within the calendar time.
Converter calendar utilization factor (ton / nominal ton · day) = qualified steel output (ton) / (converter nominal ton)×(calendar days)
4. Refining outside the furnace
Answer: transfer the primary molten steel in the steelmaking furnace to the ladle or other special container for refining, also known as secondary refining.
5. Carbon and oxygen concentration product
Answer: that is, under a certain temperature and pressure, the product of the mass percent concentration of carbon and oxygen in molten steel is a constant, which is independent of the concentration of reactants and products.
6. Red envelope tapping
Answer: bake the ladle lining until it turns red to 800 ~ 1000 ℃ in advance for tapping operation, so as to reduce the temperature drop during tapping, so as to reduce the tapping temperature, increase the amount of scrap and increase the furnace life.
7. Carburization method
Answer: when converting steel grades with an average carbon content greater than 0.08%, the blowing shall be stopped when the carbon content of liquid steel is reduced to 0.05% – 0.06%. The operation method of carburizing in the ladle to the requirements of steel grade specification during tapping is called carburizing method.
8. Double slag method
Answer: about 1 / 2-2 / 3 slag needs to be poured out or scraped out in the whole blowing process, and then slag material is added to make slag again.According to the requirements of hot metal composition and steelmaking type, slag can also be poured for many times to make new slag.In case of high phosphorus content in molten iron and high silicon content in molten iron when converting high carbon steel, double slag operation can be adopted to prevent splashing, or to prevent manganese return when converting low manganese steel.
9. Back drying
Answer: in the middle stage of oxygen top blown converter blowing, the smelting temperature is high enough and the carbon oxygen reaction is fierce. At this time, the gun position is relatively low, and the fluidity of the formed slag will often be suddenly reduced and even cause caking, which is called slag “back drying”.
10. Constant oxygen pressure changing gun operation
Answer: it refers to the oxygen blowing method in which the oxygen pressure remains unchanged during the blowing process of a furnace of steel, and the impact depth and impact area of the oxygen jet on the molten pool are adjusted by changing the gun position, so as to control the smooth progress of the smelting process.
11. Comprehensive furnace laying
Answer: during the blowing process, due to the different working conditions of various parts of the converter lining, the corrosion condition and amount of the lining are also different.In view of this situation, depending on the damage degree of lining bricks, build refractory bricks of different materials or different levels of the same material, which is the so-called comprehensive furnace building.
12. Slag retention operation
Answer: the slag retention operation is to leave part of the final slag of the upper furnace for the lower furnace.The end-point slag has high alkalinity, high temperature and certain (TFE) content. Leaving it in the next furnace is conducive to the early formation of initial slag, improve the efficiency of removing P and s in the early stage, protect the furnace lining and save the amount of lime.
13. Converter static control
Answer: it is to establish the set mathematical model based on material balance and heat balance, that is, calculate the addition amount, oxygen blowing and oxygen blowing time of molten iron, scrap, various slagging materials and coolants according to the known raw material conditions and molten steel temperature and carbon content at the end of blowing, and control the whole blowing process to the end according to the calculation results,A control method that does not correct according to any new information in the blowing process.
14. Phase diagram
Answer: in the equilibrium state, the relationship between composition and melting point is represented by a graph, which is called phase diagram.
15. Activity
Answer: due to the interaction between solute molecules and solvent molecules in the solution, the concentration may deviate when participating in the actual chemical reaction. The deviation may be positive or negative. The used concentration should be multiplied by a correction coefficient. This product is called the effective concentration, also known as activity.
16. Dynamic control of converter steelmaking
Answer: on the basis of static control, the dynamic information of relevant variables such as metal composition, temperature and slag condition changing with time in the blowing process is transmitted to the computer by means of auxiliary gun and other test means, and the blowing parameters are corrected in time according to the measured information to achieve the predetermined blowing goal.
17. Hard blowing
Answer: it means that the impact on the molten pool is deep, the impact area is small, and the stirring effect and crushing of liquid metal are strong.
18. foamed slag
Answer: under certain conditions, the CO bubbles produced by the decarburization reaction of the molten pool can disperse in large quantities in the slag, so that the volume of the slag is greatly expanded, and a thick slag layer is formed in the converter, which is even filled with the whole furnace, and the slag is called foam slag.
19. Converter volume ratio
Answer: converter volume ratio (V / T) refers to the ratio of the volume V (m) of the free space in the converter cavity to the metal loading (molten iron + scrap, unit T).
20. Blow loss
Answer: the general tapping amount in steelmaking is less than the loading amount. We call the part of metal normally lost in the blowing process blowing loss.
21. Indirect oxygen transfer
Answer: oxygen is introduced into molten metal through slag, and its reaction formula is: (FeO) = [FeO], [FeO] = [Fe] + [O];Indirect oxygen transfer is the main oxygen transfer in the blowing process.
22. Chemical affinity
Answer: refers to the strength of the combination ability between elements.
23. Phase
Answer: the part of the system we study that has the same physical properties and is uniform.
24. Impact area
Answer: the area of the oxygen stream in contact with the calm metal surface.
25. Precipitation deoxidation
Answer: adding deoxidizer into liquid steel and deoxidizing products are produced in liquid steel in the form of precipitation. The deoxidation method is called precipitation deoxidation.
26. End point control
Answer: it mainly refers to the control of endpoint temperature and composition.For the end-point control of converter, it is not only necessary to ensure the accurate hit of key carbon and temperature, and ensure that P and s components meet the tapping requirements, but also to control the oxygen content of molten steel as low as possible.
27. Laval nozzle
Answer: the Laval nozzle is a contraction expansion orifice. The ratio of outlet oxygen pressure to inlet oxygen pressure is less than 0.528, forming a supersonic jet.The velocity of the gas at the throat is equal to the speed of sound and reaches supersonic velocity at the outlet.
28. Lime activity
Answer: it refers to the reaction capacity between lime and slag. It is an index to measure the dissolution rate of lime in slag.29. Non metallic inclusions
Answer: oxides, sulfides, nitrides and other non-metallic phases produced or mixed into steel during smelting and pouring, which cannot be eliminated after processing or heat treatment and exist independently without any connection with the steel matrix are collectively referred to as non-metallic inclusions, or inclusions for short.
30. Economic life of converter
Answer: according to the relationship between converter life, cost and steel output, the comprehensive consumption of materials is the least, the cost is the lowest and the output is the most. The best furnace life determined under the condition of ensuring steel quality is the economic furnace life.
31. Slag alkalinity
Answer: the ratio of the total concentration of alkaline oxides in the slag to the total concentration of acidic oxides becomes the basicity of the slag.
32. Static model
Answer: according to the calculation of material balance and heat balance, and then referring to the correction coefficient obtained from the statistical analysis of empirical data, determine the blowing charge and oxygen consumption, and predict the end-point molten steel temperature and composition target.
33. Oxygen supply intensity
Answer: oxygen supply intensity is the amount of oxygen supplied by the spray gun per ton of metal material in unit time (unit m3 / T · min).
34. Blowing loss
Answer: it refers to the ratio percentage of the difference between the converter charge minus the steel output and the charge.
35. Impact depth
Answer: the impact depth, also known as the penetration depth, refers to the maximum depth that can be reached at the center of the oxygen stream when it is injected into the molten steel.
36. Quantitative loading
Answer: the quantitative loading system is to keep the loading amount of each furnace unchanged during the whole furnace service, so as to facilitate the production organization and stable operation.
37. Soft blowing
Answer: it refers to the oxygen blowing operation with high gun position or low oxygen pressure. At this time, the impact depth of the molten pool is shallow, the impact area is large, and the stirring effect and crushing of the molten metal are weak.
38. Loading system
The answer is to determine the reasonable loading of converter and the appropriate ratio of molten steel to scrap steel, so as to obtain the best technical and economic indicators.
39. Diffusion deoxidation
Answer: diffusion deoxidation refers to adding deoxidizer to the slag to transfer and diffuse the oxygen in molten steel to the slag by reducing the TFE content in the slag, so as to reduce the oxygen content in molten steel.The deoxidation time is longer and the alloy consumption is less, but it is easy to cause endogenous inclusions.
40. Single slag shoving
Answer: single slag operation refers to the slag making method of making slag only once in the smelting process without scraping and pouring slag in the middle.

Single choice questions (130 questions)

1. The lump size of scrap steel entering the furnace shall not be too large and shall be less than () of the furnace mouth diameter.
A.1/2B.1/3C.1/4D.1 / 5 answer: a
2. The highest content of oxygen top blown converter steelmaking slag is ().A.FeOB.MgOC.CaOD.SiO2 answer: C
3. When returning to dry in the middle of blowing, the purpose of appropriately raising the gun position is ().
A. Reduce iron oxide in slag B. increase iron oxide in slag C. increase furnace temperature answer: B
4. The following cooling effects are the best: ().
A. Ore B. pig iron block C. lime D. dolomite answer: a
5. The harm of phosphorus is to increase the of steel ().
A. Hot crisp B. cold crisp C. blue crisp D. red crisp answer: B
6. Among the following elements, the element with the largest calorific value in the oxygen converter is ().A. Carbon B. silicon C. phosphorus answer: a
7. Steel is divided into boiling steel and killed steel according to ().
A. Quality B. smelting method C. deoxidation degree D. chemical composition answer: C
8. The correct description of the reaction rate of carbon and oxygen is ().A. The carbon content of molten iron is high in the early stage of smelting, and the reaction speed of carbon and oxygen is the fastest. B. the reaction speed is the fastest in the middle stage of smelting
C. In the later stage of smelting, the temperature is high, and the reaction speed of carbon and oxygen is the fastest. Answer: B
9. Hard blowing refers to the blowing mode of ().
A. Low gun position or high oxygen pressure B. high gun position or low oxygen pressure C. low gun position or low oxygen pressure answer: a
10. If the activity of lime is greater than () ml, it is active lime.
A.280B.300C.320 answer: B
11. The gun position during converter smelting refers to: ().
A. Distance between oxygen lance nozzle and furnace bottom B. distance between oxygen lance nozzle and molten pool liquid level C. distance between oxygen lance nozzle and molten pool slag surface answer: B
12. The lower the oxygen content in equilibrium with a certain concentration of deoxidizing element, the deoxidizing ability of this element ().
A. Stronger B. weaker C. irrelevant answer: a
13. Among the following steel grades, the one with the lowest melting point is ().
A.Q235B.Q195C.HRB335 answer: B
14. Under the same conditions, the gun position control of combined blown converter is generally better than that of top blown converter ().
A. Lower than top blown converter B. same as top blown converter C. slightly higher than top blown converter answer: C
15. Economic furnace life refers to ().
A. High output and high consumption of refractory materials B. high furnace life, high output and long furnace service time C. high furnace service productivity and low comprehensive cost answer: C
16. The common conditions for sulfur and phosphorus removal reactions are ().
A. High temperature and high iron oxide B. low temperature and low iron oxide C. high alkalinity and large amount of slag answer: C
17. The relationship between decarburization rate of converter and ferrous oxide content in slag is ().
A. The faster the decarburization rate, the lower the ferrous oxide
B. The lower the content of ferrous oxide in slag, the lower the decarburization rate
C. Decarburization rate has nothing to do with ferrous oxide content answer: a
18. Carbon oxygen product M = [% C] · [% O], m at a certain temperature is a constant, which represents the quantitative relationship between carbon and oxygen in the metal molten pool.When t = 1600 ℃, PCO = 0.1MPa, M = ().
A. 0.0025b.0.025c.0.25 answer: a
19. For aluminum killed steel, the purpose of feeding CA alloy cored wire before casting is ().
A. Deoxidation B. desulfurization C. improving the fluidity of molten steel D. fine tuning the aluminum content in molten steel answer: C
20. During alloying in ladle during tapping, the main factor affecting alloy yield is ().
A. Length of tapping time B. temperature of molten steel C. amount of slag and iron oxide content in slag answer: C
21. Non metallic inclusions that do not belong to foreign inclusions are ().
A. Eroded refractory B. dirt brought in by furnace charge C. deoxidation product answer: C
22. The main reason for the erosion of the nozzle end of the oxygen lance is ().
The A. gun position is normal, but the furnace temperature is high. B. oxygen lance is blowing time in the furnace slag foams for a long time. C. ends of the nozzle are glued to reduce the melting point of the nozzle. The answer is: C
23. Sulfur mainly exists in the form of FES in steel. When molten steel solidifies, FES and Fe form low melting point eutectic, and its melting point is () ℃.
A.895B.985C.1055 answer: B
24. If the content of [P] in steel is 0.020%, the content of [P] in steel is () ppm.
A.20B.200C.2000D.2.0 answer: B
25. Oxygen is the main oxidant of oxygen converter steelmaking, and its oxygen purity is required to be more than ().A. 95.0% b.99.0% c.99.6% d.99.9% answer: C
26. The main contents of non endpoint control are ().
A. The carbon content in steel reaches the specification range B. the iron oxide in slag is within a certain range C. the temperature meets the tapping requirements answer: B
27. Ordinary, high-quality and high-quality carbon steel are distinguished according to ().
A. Mechanical properties B. s, P content C. Mn, Si content answer: B
28. The oxidation ability of elements from strong to weak is correct ().
A.Mn、Si、AlB.Al、Mn、SiC.Al, Si, Mn answer: C
29. The effect of silicon on the properties of steel is ().
A. Improve the weldability and processability of steel B. improve the impact of steel and increase the elongation C. increase the strength and elasticity of steel answer: C
30. At present, one of the key equipment for converter gas recovery in China is R-D valve. The function of R-D valve is ().
A. Control flue gas flow B. control dust removal cooling water flow C. adjust flue gas flow and control micro pressure difference at furnace mouth answer: C
31. Judge the carbon content of molten steel from the spark of steel sample. When the carbon flower is thin and the radian is small, it is divided into 3 ~ 4 forks and falls to the ground as “chicken feet”, the carbon content at this time is ().
A. 18% ~ 22% B. 0.12 ~ 0.16% C. < 0.10% answer: B
32. The erosion process of furnace lining is carried out in a circular way according to the mechanism of ().
A. Erosion oxidative decarbonization erosion B. oxidative decarbonization erosion erosion C. erosion oxidative decarbonization erosion answer: B
33. The amount of slag formed per ton of metal material is less than () kg, which is called less slag operation
A.30B.40C.50 answer: a
34. Soft reduction technology is mainly used to improve the quality of billet ().
A. Centerline crack B. central segregation C. scarring D. transverse crack answer: B
35. Which smelting indexes are unfavorable for converter back blowing ().
A. Reduce iron loss B. reduce inclusions in steel C. dephosphorization D. improve lining life answer: abd
36. The addition order of deoxidizer is () which is conducive to the removal of inclusions.
A. First strong then weak B. first weak then strong C. both can answer: B
37. The places where co bubbles cannot be generated in the molten pool are ().
A. Interior of homogeneous metal bath B. lining surface C. surface of solid particles suspended in solution answer: a
38. The most widely used deoxidation method in modern steelmaking is ().
A. Precipitation deoxidation B. diffusion deoxidation C. vacuum deoxidation D. compound deoxidation answer: a
39. The order of affinity between silicon, aluminum, manganese and oxygen is ().
A. Silicon > Aluminum > manganese B. aluminum > silicon > manganese C. manganese > Aluminum > silicon D. aluminum > manganese > silicon answer: B
40. The type of converter refers to ().
A. Shell shape B. lining inner type C. furnace volume D. furnace condition during shutdown answer: B
41. Mach number (MA) is an important parameter of oxygen lance nozzle, which determines the impact capacity of oxygen flow to molten pool. Generally, Ma is ().
A. About 1.0 b.2.0 c.3.0 answer: B
42. After sampling and observing the used residual bricks, it is found that the section of residual bricks is divided into () three layers in turn.
A. Decarburization layer → original layer → slag layer B. original layer → slag layer → decarburization layer C. slag layer → decarburization layer → original layer answer: C
43. The correct expression of lime addition amount is ().
A. (2.14 [% SiO2] / ê o effective)×R×1000B. [2.14 [% Si] / (ê o lime-r% SiO2 lime)]×R×1000C．(2.14[%Si]/êO)×R×1000 answer: B
44. In the production practice of converter steelmaking, the oxidizability of general slag refers to ().
A. Sum of oxygen content in oxides such as (CAO), (MgO), (FeO), (Fe2O3), (MnO), (P2O5) B. sum of concentration of (CAO), (MgO) C. sum of concentration of (FeO), (Fe2O3) answer: C
45. One of the conditions for obtaining supersonic flow strands must be the outflow of high-pressure gas, and the inlet and outlet pressure difference must be greater than the critical pressure difference, i.e. ().
A. P out / P in < 0.438b. P out / P in < 0.528c. P out / P in < 0.628 answer: B
46. Aluminum oxide (Al2O3) in steelmaking slag belongs to () oxide.
A. Acid B. weak acid C. amphoteric answer: C
47. The relationship between slag viscosity and dephosphorization reaction rate is ().
A. The smaller the slag viscosity is, the faster the reaction speed is. B. the larger the slag viscosity is, the faster the reaction speed is. C. the smaller the slag viscosity is, the slower the reaction speed is. Answer: a
48. Which of the following is not a commonly used molten iron De-S agent ().
A.CaC2B.Metal MGCMetal Al answer: C
49. Which of the following is not the converter steelmaking temperature system ().
A. Process temperature control B. end point temperature control C. hot metal temperature control answer: C
50. In the process of converter steelmaking, due to the top blowing of oxygen, the molten steel, molten slag and oxygen in the furnace form (), which strengthens the ability of converter to remove P and s.
A. Emulsification phenomenon B. mixing phenomenon C. slag answer: a
51. () is the most ideal deoxidizer under vacuum.
A. Carbon B. silicon C. aluminum D. manganese answer: a
52. Combined blowing thermal efficiency () thermal efficiency of oxygen top blowing converter.
A. Higher than B. lower than C. equal to D. less than answer: a
53. The varieties of steel can be divided into () according to chemical composition and purpose.
A. Carbon steel, alloy steel B. plain carbon steel, high-quality steel, high-grade high-quality steel C. killed steel, semi killed steel, boiling steel D. structural steel, tool steel, special performance steel answer: D
54. () as the bottom air source of the combined blowing process, it can play a good mixing effect and cooling effect.
A. Argon B. nitrogen c.co2d.co answer: C
55. The judgment index of the fluidity of lime is ().
A. Particle size B. burn down C. natural reactor angle D. sulfur content answer: C
56. The parameters affecting the energy conversion effect of oxygen lance orifice are ().
A. Number of orifices B. ejection coefficient C. expansion angle D. orifice inclination answer: C
57. In steelmaking coolant, () is close to the cooling effect of ore.
A. Scrap steel B. sheet iron C. pig iron D. lime answer: B
58. When the ratio of manganese to silicon in molten iron is (), it is beneficial to smelting operation.
A. 1.0 ～ 1.2b. 2.5 ～ 3.0c. 0.8 ～ 1.0d. 0.4 ～ 0.7 answer: C
59. Acid soluble aluminum in finished product inspection is ().
A. Aluminum and aluminum nitride B. aluminum and aluminum trioxide C. aluminum D. aluminum trioxide answer: a
60. The following elements added to molten steel can play the role of precipitation strengthening ().
A．Nb、V、TiB．Nb、V、CuC．Al、V、CuD.Ti, Al, V answer: a
When the carbon content of molten steel is 0.04%, the theoretical equilibrium oxygen content is () ppm
A. 1000B. 100C. 625d. 62.5 answer: C
62. In the middle of blowing, the mineral composition of slag is mainly ().
A. Olivine B. calcium disilicate and calcium trisilicate C. calcium trisilicate and free CaO. Free CaO answer: B
63. The relationship between decarburization rate of converter and ferrous oxide content in slag is ().
A. The faster the decarburization speed, the lower the ferrous oxide. B. the lower the ferrous oxide content in the slag, the lower the decarburization speed. C. the decarburization speed has nothing to do with the ferrous oxide content in the slag. Answer: a
64. Comparison between straight cylinder oxygen lance nozzle and Laval oxygen lance head ().
A. Straight barrel nozzle can obtain more stable supersonic jet under high pressure. B. Laval nozzle can obtain more stable supersonic jet under high pressure. C. The effects of the two nozzles are similar. Answer: B
65. The main features of double channel oxygen lance are to increase oxygen supply intensity, shorten blowing time and ()
A. Adverse thermal compensation B. no effect on thermal compensation C. favorable thermal compensation answer: C
66. The main function of setting iron mixer in steelmaking plant is to store molten iron ().
A. Keep hot metal warm and warm B. keep hot metal warm and uniform composition C. keep hot metal warm and uniform composition answer: B
67. Carbon can improve the () properties of steel.
A. Welding B. corrosion C. strength answer: C
68. The loading system commonly used in the operation of small and medium-sized oxygen top blown converter is ().
A. Quantitative loading system B. fixed depth loading system C. phased quantitative loading system answer: C
69. High content of () in slag is beneficial to desulfurization.A. Silica
B. Aluminum oxide, phosphorus pentoxide and magnesium oxide C. calcium oxide and manganese oxide answer: C
70. The main factor affecting the oxygen content in molten steel at the end of blowing is ().
A. End point carbon content of molten steel B. residual manganese content in molten steel C. molten steel temperature answer: a
71. The diameter of converter molten pool is related to ().
A. Metal loading and oxygen blowing time B. metal loading and oxygen blowing intensity C. metal loading and oxygen blowing flow answer: a
72. If the content of () in molten iron is too high, it will add a large amount of lime, which is easy to cause splashing.
A. MNB. SiC. P answer: B
73. The following oxides () are acidic oxides.
A. SiO2, mnob.mgo, caoc.sio2, P2O5 answer: C
74. The gun position during converter smelting refers to ().
A. Distance between oxygen lance nozzle and furnace bottom B. distance between oxygen lance nozzle and molten pool liquid level C. distance between oxygen lance nozzle and molten pool slag surface answer: B
75. In general, the density of pure molten iron increases with the increase of temperature ().
A. Raise B. lower C. constant answer: B
76. [FeO] + [C] = [Fe] + {co} is a () reaction.
A. Endothermic B. exothermic C C. neither endothermic nor exothermic answer: a
77. [al] s denotes ().
A. Al2O3 dissolved in steel 3B. All aluminum in steel C. acid soluble aluminum in steel answer: C
78. Under the same conditions of (TFE), the distribution ratio of phosphorus in combined blowing converter is higher than that in top blowing converter (a), B. lower, C. unchanged answer: B
79. The reaction between C in steel and (FeO) in slag is a ().
A. Exothermic reaction B. endothermic reaction C. neither endothermic nor exothermic answer: B
80. LD is named after ().
A. Person name B. place name C. time D. animal name Answer: B
81. Magnesia carbon brick is characterized by ().
A. Good high temperature resistance and slag resistance B. good high temperature resistance and poor slag resistance C. poor high temperature resistance and good slag resistance answer: a
82. In the middle of blowing, the decarburization reaction rate is determined by ().
A. Oxygen supply intensity and gun position determine B. molten pool temperature and oxygen supply intensity determine C. mainly determined by oxygen supply intensity D. oxygen supply intensity and molten pool temperature determine answer: C
83. The description of slag viscosity is wrong ().
A. The viscosity of acidic slag decreases a lot with the increase of temperature. B. the viscosity of alkaline slag first decreases rapidly with the increase of temperature, and then decreases slowly. C. the fluidity of molten slag is good and the viscosity is low
D. With the increase of high melting point components in the slag, the fluidity will become worse. Answer: a
84. For slab casting with large section, the () continuous caster is generally selected.
A. Full arc B. horizontal C. vertical bending D. oval answer: C
85. The function of oxygen lance nozzle is ().
A. Pressure energy becomes kinetic energy B. kinetic energy becomes velocity energy C. stirring molten pool answer: a
86. () oxides have the highest melting point.
A. MgO · sio2b.cao · sio2c.2cao · SiO2 answer: C
87. the main reason for the formation of foamed slag is ().
A. High slag temperature B. low slag temperature c. a large amount of CO gas is dispersed in the slag answer: C
88. According to the exothermic capacity of oxidation reaction of each element, the order of calorific value per kilogram of elements in molten iron is ().
A. C, Si, Mn, P, feb.si, Mn, C, Fe, pc.p, Si, C, Mn, Fe answer: C
The oxidation order of elements in molten iron at 89.1400 ℃ – 1530 ℃ is ().A.SiMnCFePVB.SiCMnFeVPC.SiCVMnPFeD.Csimnfepv answer: C
90. After the application of slag splashing technology, the main reason for the rise of furnace bottom is ().
A. Heavy metals infiltrate into the cracks of furnace bottom bricks to make the furnace bottom bricks float upward. B. undissolved lime and light burning are concentrated on the furnace bottom. C. high melting point crystalline phases C2S, C3S and MgO are adhered to the furnace bottom. D. cold steel is adhered to the furnace bottom. Answer: C
91. The correct chemical reaction formula for S removal in converter is ().A. [FES] + (CAO) = (FeO) + [CAS] B. [FES] + (MnO) = (FeO) + (MNS) C. [CAS] + 3 (Fe2O3) = {SO2} + 6 (FeO) + (CAO) D.2 [CAS] + 3 {O2} = 2 {SO2} + 2 (CAO) answer: B
92. In the ternary state diagram of calcium oxide (CAO), ferrous oxide (FeO) and silicon dioxide (SiO2), the melting point of three pure oxides and their corresponding pure oxides is ().
A. Three vertices B. three sides C. three corners answer: a
93. The effect of aluminum in steel on the properties of steel is ().
A. Refine grains and increase strength B. refine grains and improve corrosion resistance C. reduce corrosion resistance D. refine grains and improve impact properties answer: D
94. The melting point of Al2O3 is ().
A. 1100 ℃ b.1539 ℃ c.1650 ℃ d.2030 ℃ answer: D
95. The expression of slag desulfurization capacity is ().
A. Ls = [S%] / (s%) B. LS = (s%) / [S%] C. LS = (s%) / [S] 2 answer: B
96. According to the national standard (GB700-88), the correct expression order of carbon structural steel grades is: ().A. Letter representing yield strength, quality grade, deoxidation method, yield strength value B. quality grade, letter representing yield strength, yield strength value, deoxidation method C. letter representing yield strength, yield strength value, quality grade, deoxidation method answer: C
97. The main function of converter steelmaking ore is ().
A. Slagging agent B. coolant C. warming agent D. carburizing agent answer: B
98. The converter loading of large converter steel plant with full continuous casting should be ().
A. Phased quantitative loading B. fixed depth loading C. quantitative loading answer: C
99. The basicity of converter slag is generally controlled at about ().
A. 1.0b. 2.0c. 3.0 answer: C
100. The phenomenon of “back drying” is easy to occur in ().
A. Early stage of blowing B. middle stage of blowing C. late stage of blowing answer: B
101. The main reason for steel sticking of oxygen lance is ().
A. gun position is high and foam splashing occurs in the early stage of B. smelting. The furnace temperature is low, the gun position is high and the slag of C. is not good to produce metal splash. The answer is: C
102. The main function of fluorite is to improve the fluidity of slag, and its main component is ().
A. Caf2b.cac2c.cas answer: a
103. When the oxygen supply intensity is certain, when the gun position increases and the oxygen pressure decreases, the oxidizability of slag ().
A. Strengthen B. weaken C. constant answer: a
104. Fe2O3 in slag is () oxide.
A. Alkaline B. acidic C. neutral answer: C
105. Temperature control of converter refers to ().
A. Blowing end point temperature control B. blowing process temperature control C. blowing process temperature and blowing end point temperature control
Answer: C
106. Main requirements for lime for steelmaking ().
A. High effective calcium oxide, high content of silicon dioxide and sulfur and low over burning rate B. low effective calcium oxide, low content of silicon dioxide and sulfur and low over burning rate C. high effective calcium oxide, low content of silicon dioxide and sulfur and low over burning rate answer: C
107. Under certain oxygen supply intensity, the relationship between gun position and iron oxide in slag is ().
A. Increasing the gun position can increase the iron oxide content in the slag. B. reducing the position grab can increase the iron oxide content in the slag. C. the iron oxide content in the slag has nothing to do with the gun position. Answer: a
108. The description of batch number and adding time of slag making material is correct ().
A. Slagging materials are generally evenly added in three batches in the early, middle and late stages of the smelting process
B. The slag is basically added in two batches. The first batch of slag is added at the same time of blowing. The second batch of slag is added when the oxidation of silicon and manganese is basically completed, the first batch of materials is basically good, and it is more appropriate to add at the beginning of carbon flame.Depending on the slag situation, the third batch of materials can also be added as appropriate. C. It is not necessary to add slagging materials in batches, as long as they are added evenly. Answer: B
109. The main purpose of slag retaining and tapping is ().
A. Reduce back phosphorus B. conducive to secondary refining of molten steel C. reduce cooling answer: a
110. The oxidizability of slag is represented by ().
A．RB．ΣFeoc.mgo answer: B
111. Among the following deoxidizers, the one with the strongest deoxidation ability is ().
A. Fe sib.fe-mnc.al answer: C
112. The function of active lime for converter steelmaking is ().
A. Increase furnace life B. increase alkalinity C. conducive to slag formation D. conducive to decarbonization answer: C
113. The effect of multiple supplementary blowing on oxygen consumption per ton of steel is ().
A. Increase B. no effect C. decrease answer: a
114. Single slag operation is in the whole smelting process ().
A. Slag is added at one time. B. slag is poured once in the middle. C. slag is only made once. Slag is not poured or scraped in the middle until the end of tapping. Answer: C
115. In the basic converter steelmaking process, the most completely oxidized element is ().
A. Mnb.cc.si answer: C
116. Phosphorus content in molten iron ().
A. The higher the better B. the lower the better C. moderate answer: B
117. When returning to dry in the middle of blowing, properly improve the gun position operation, which is for ().
A. Increase ferrous oxide in slag B. increase furnace temperature C. increase stirring strength of molten pool answer: a
118. The main source of endogenous inclusions in steel is ().A. Erosion of refractory materials of furnace lining and steel drum
B. Elements in smelting process are oxidized and deoxidized to form oxide C. inclusions in furnace charge answer: B
119. It is better to add dolomite for Slagging in ().
A. Early stage of blowing B. middle stage of blowing C. late stage of blowing answer: a
120. In order to reduce the dephosphorization of ladle, the amount of slag from tapping should be ().
A. Add B. control to the minimum C. do not control answer: B
The solubility of 121. H in molten steel increases with the increase of temperature ().
A. Answer: C. increase
122. When the oxide decomposition reaction reaches equilibrium, the gas pressure generated is the decomposition pressure.If the oxide is more stable, the（
A. The larger the decomposition pressure is, B. the smaller the decomposition pressure is, C. It has nothing to do with the decomposition pressure. Answer: B
123. When splashing occurs, the oxygen lance should be ().
A. A little more B. a little lower C. immobile answer: a
124. The following () raw materials are not coolant.
A. Scrap B. ore C. dolomite D. iron oxide scale answer: C
125. Copper causes steel to produce () when heated.A. Hot brittleness B. cold brittleness C. hardenability answer: a
126. When the carbon of the molten steel at the end of the converter is low and the temperature is low, the temperature should be increased by () supplementary blowing to avoid the peroxidation of the molten steel.
A. Add slagging agent B. lower the gun position C. add an appropriate amount of temperature increasing agent into the furnace answer: C
127. During converter blowing, the main cause of slag “back drying” is ().
A. Large amount of slag B. oxygen supply is greater than the oxygen consumption of carbon oxygen reaction C. oxygen supply is less than the oxygen consumption of carbon oxygen reaction
Answer: C
128. In oxygen top blown converter steelmaking, the necessary condition for oxygen to transfer to the metal bath through slag is ().
A．PO2{O2}＞PO2{FeO}＞PO2[FeO]；B．PO2{O2}＜PO2{O}＜PO2[FeO]；
C．PO2{O2}＞PO2[FeO]＞PO2[FeO]。Answer: a
129. The crystallization and solidification of liquid steel into billet during casting is carried out by ().
A. From high temperature to low temperature at the same time B. the liquid steel starts when it is cooled to the crystallization temperature C. the liquid steel starts when it is cooled to a certain temperature below the crystallization temperature answer: C
130. The description of deoxidation and alloying is correct ().
A. Deoxidation first and then alloying B. alloying first and then deoxidation C. deoxidation and alloying are completed at the same time in the steelmaking process

Judgment questions (130 questions)

1. The heat source of converter steelmaking mainly comes from the physical heat and chemical heat of molten iron.() answer: √
2. After the oxygen stream is sprayed out of the oxygen gun nozzle, the pressure becomes smaller and smaller, and the air velocity becomes smaller and smaller.() answer: √
3. The recovery rate of manganese in tapping alloying is greater than that of silicon.() answer: √
4. The correct gun position curve shall meet the requirements of good slagging, less splashing, fast decarburization and high dephosphorization rate.() answer: √
5. Excessive loading will increase splashing, make slagging difficult and shorten the service life of furnace cap.() answer: √
6. The oxidation capacity of slag refers to the sum of all oxide concentrations of slag.() answer:×
7. The furnace with large furnace capacity ratio is not prone to large splashing.() answer: √
8. During the blowing process, when the gun position control is high or the oxygen pressure is low, the flame is relatively soft and the carbon drawing is easy to be high.() answer: √
9. The purpose of argon blowing and stirring molten steel in ladle is mainly to improve the temperature of molten steel.() answer:×
10. When the temperature of molten iron is low, the operation of low gun position can speed up the heating rate of molten iron bath.() answer: √
11. Poor deoxidation of molten steel is the main cause of subcutaneous bubbles in billet.() answer: √
12. Properly high manganese content in molten iron is conducive to rapid slag formation.() answer: √
13. The collection methods of converter flue gas include wet method and dry method.() answer:×
14. Sulfur is a harmful element in steel. Sulfur makes the steel produce thermal embrittlement during hot processing, reduces the mechanical and welding properties of the steel, and destroys the cutting properties of the steel.() answer:×
15. Blow argon at the bottom of the ladle, and the best position of the breathable brick is in the center of the bottom of the ladle.() answer:×
16. The oxygen lance nozzle made of red copper is mainly due to its poor thermal conductivity.() answer:×
17. Nitrogen supply at the bottom of the whole blowing process has no effect on the nitrogen content of molten steel.() answer:×
18. The activity of lime refers to the reaction ability of Cao with other substances in slag.() answer: √
19. After adding alloy into molten steel, the solidification point of molten steel will increase. The more alloy is added, the higher the solidification point will be.(answer:×
20. The measures to improve the slab quality are mainly to improve the ratio of columnar crystals.() answer:×
21. Reduction ability of H2 and CO: when the temperature is lower than 818 ℃, the reduction ability of CO is stronger than that of H2.() answer: √
22. When the oxygen content in steel is high, the nitrogen absorption capacity of molten steel is strengthened.() answer:×
23. The central carbon segregation of high carbon steel billet increases with the increase of carbon content.() answer: √
24. The stronger the argon blowing stirring in the ladle, the shorter the uniform time of molten steel composition and temperature, and the lower the inclusions in the steel.() answer:×
25. Mold vibration is to prevent the primary green shell from being pulled and leaked due to adhesion with the mold.() answer:×
26. Acid soluble aluminum refers to AlN and dissolved aluminum in steel obtained by acid dissolution method.() answer: √
27. CAS-OB refining process refers to argon blowing and alloying in the package.() answer:×
28. When there is residual liquid slag of high iron oxide in the furnace, iron mixing will produce splashing accident.（）
Answer: √
29. For most carbon manganese steels, the addition of rare earth in the steel does not significantly improve the impact value of the steel, but has a significant effect on the strength.() answer:×
30. Top blown oxygen stirring can be directly proportional to the flow rate at the outlet of the oxygen lance nozzle and inversely proportional to the outlet diameter of the nozzle.() answer:×
31. The amount of dissolved carbon in ferrite is between 0.008% – 0.0218%, which is the main component of steel.() answer: √
32. Under the same working conditions, the copper pipe lubricated by protective slag or oil shall be selected, and the taper of the former shall be greater than that of the latter.() answer: √
33. The main inspection items involved in the metallographic structure analysis of typical wire rod include: metallographic structure, decarburization layer, sorbitic rate, etc.() answer: √
34. the relationship between foaming slag and surface tension is the following: the greater the surface tension, the easier to form foamed slag.() answer:×
35. The lower the basicity of the slag, the higher the FeO content and the higher the bath temperature, the higher the reduced manganese and the higher the “residual manganese” in the molten steel.() answer:×
36. When there are bubbles in liquid steel, [C] and [O] will diffuse to the bubble surface and adsorb on the bubble surface for chemical reaction.() answer:×
37. The higher the carbon content, the higher the crack sensitivity in the crystalline two-phase region.() answer: √
38. Refractory products are substances composed of a variety of minerals, which soften and then melt after heating, so there is no fixed melting point.() answer: √
39. SiO2 in slag is more unstable than MnO.() answer:×
40. Dephosphorization reaction is exothermic, so low temperature is conducive to dephosphorization.() answer: √
41. The main component of metallurgical lime is (CAO), and its SiO2 content has little effect on its quality.() answer:×
42. Blowing AR can reduce the gas content of molten steel.() answer: √
43. Single slag method is a method of adding slag forming agent into the furnace at one time during blowing.() answer:×
44. In converter blowing, the main reason for the “back drying” phenomenon of slag is that the oxygen supply is less than the oxygen consumption of carbon oxidation reaction.() answer: √
45. Carbon can improve the corrosion resistance of steel.() answer:×
46. The effect of aluminum in steel on the properties of steel is to refine grain and improve toughness.() answer: √
47. The change law of decarburization rate of converter is that the decarburization rate changes from high to low because the carbon content in iron changes from high to low.() answer:×
48. In general, dephosphorization and desulfurization are mainly carried out in the middle of smelting.() answer:×
49. In the steelmaking process, temperature control is actually to determine the time and amount of coolant added.() answer:×
50. Among the elements in molten iron, carbon has the largest heating capacity.() answer:×
51. In the converter smelting process, decarburization and dephosphorization can be carried out simultaneously as long as they are properly controlled.() answer: √
52. MnO and Al2O3 are alkaline oxides.() answer:×
53. According to the quality classification, the varieties of steel can be divided into ordinary steel, high-quality steel and high-quality steel.() answer: √
54. Alkaline oxides in slag include Cao, MgO, P2O5, etc.() answer:×
55. Oxygen in steel exists mainly in the state of dissolution and compound, and rarely in the state of free.() answer: √
56. In case of splashing, lower the gun.() answer:×
57. After the furnace bottom rises, the lining erosion at the furnace cap is the most serious.() answer: √
58. As a coolant, iron ore has stable cooling effect and less slag formation than iron oxide scale.() answer:×
59. When the elements in the converter molten iron are oxidized in the same amount, the most heat release is carbon.() answer:×
60. High phosphorus in steel is easy to cause “cold embrittlement”, which intensifies with the increase of carbon, nitrogen and oxygen content in steel. Answer: √
61. (Fe0) + [C] = [Fe] + {C0} is an endothermic reaction.() answer: √
62. Adding a certain amount of Cu to the steel can improve the strength, but it is also easy to cause cracks.() answer: √
63. The distribution coefficient of phosphorus is LP = [P] / (P), which indicates the dephosphorization capacity of slag. The greater the ratio, the greater the dephosphorization capacity.() answer:×
64. Compared with the water inlet speed, the water inlet speed of oxygen lance cooling water is generally greater than the water return speed.() answer: √
65. The dephosphorization phenomenon of killed steel in ladle is more serious than that of boiling steel.() answer: √
66. The greater the interfacial tension between steel and inclusions, the smaller the interfacial tension between slag and inclusions, which is more beneficial to the removal of inclusions.() answer: √
67. Generally, in smelting low carbon steel, the temperature should be controlled slightly higher.() answer: √
68. Under the same materials and external environmental conditions, the nitrogen and hydrogen contents in oxygen top blown converter steel are lower than those in electric furnace.() answer: √
69. The melting point of slag refers to the temperature at which the slag begins to melt.() answer:×
70. When the converter tapping is alloyed in the ladle, the main factor affecting the alloy recovery is the short tapping time.() answer:×
71. Due to the continuous reaction of carbon and oxygen, oxygen top blown converter can smelt ultra-low carbon steel.() answer:×
72. The activity of silicon dioxide in alkaline slag is very low and silicon reduction will not occur.() answer: √
73. The ability of slag to oxidize impurities in metal solution is called the oxidizability of slag.() answer: √
74. Steel is divided into killed steel, boiling steel and alloy steel according to the degree of deoxidation.() answer:×
75. Lime is the main slag making material for steelmaking and has considerable dephosphorization and desulfurization capacity. Therefore, it must be added at one time during blowing.() answer:×
76. Molten iron quality mainly refers to that the temperature of molten iron meets the requirements without special provisions on the composition.() answer:×
77. The basic conditions for removing s are high FeO, low Cao and high temperature.() answer:×
78. The basic principle of gun position control in the blowing process is to melt the slag and decarbonize quickly, which has nothing to do with the furnace temperature.（）
answer:×
79. For the end of blowing, the higher the basicity of slag, the more conducive to dephosphorization.() answer:×
80. In steelmaking, lime is required to have high SiO2 content and low CaO content.() answer:×
81. There are two ways of oxygen transfer in the blowing process: direct oxygen transfer and indirect oxygen transfer.() answer: √
82. Silicon is oxidized in the initial stage of smelting in any steel-making method.() answer: √
83. In the operation of oxygen top blown converter, the slag forming speed of low gun position is faster than that of high gun position.() answer:×
84. Vanadium in steel can improve the strength limit, yield limit and elastic limit of steel.() answer: √
85. When the slag is “back dry”, the slag shall be reduced in time.() answer:×
86. Under the same conditions, the higher the molten pool temperature, the brighter and stronger the furnace mouth flame.() answer: √
87. The purpose of feeding silicon calcium wire to the ladle is to further deoxidize the molten steel (answer:×
88. In the period of intense carbon oxidation, the content of (FeO) is often low, which is prone to the “back drying” phenomenon of slag, resulting in metal splashing.() answer: √
89. Since the dephosphorization reaction is mainly carried out in the early stage of smelting, low alkalinity is conducive to the dephosphorization reaction. Answer:×
90. The dynamic control of converter steelmaking is conducive to improving the hit rate of the end point and reducing the number of furnace switching.() answer: √
91. Under the condition of a certain sulfur distribution coefficient, the sulfur content in steel depends on the sulfur content and slag content in the charge.() answer: √
92. In the steelmaking process, FeO in slag increases gradually with the decrease of decarburization rate.() answer: √
93. The solubility of argon in steel grade decreases with the increase of molten steel temperature.() answer:×
94. The main purpose of deoxidation is to remove excess oxygen from steel, but the task of adjusting the composition and alloying of steel must be completed during deoxidation.() answer: √
95. Production practice has proved that the phenomenon of dephosphorization in the ladle of killed steel is more serious than that of boiling steel.() answer: √
96. Inclusions can be divided into endogenous inclusions and exogenous inclusions according to their sources.() answer: √
97. Whether a chemical reaction can proceed spontaneously has nothing to do with the concentration of reactants and products.() answer:×
98. The greater the strength of secondary cooling water in continuous casting, the more developed the central equiaxed crystal and the narrower the columnar crystal.() answer:×
99. Within the steel-making temperature range, the product of [% C] and [% O] in the molten pool is basically a fixed value.() answer: √
100. Adding any substance that can reduce the melting point of slag can improve the fluidity of slag, such as CaF2, MnO, FeO, etc.() answer: √
101. The purpose of adding ferroalloy into the ladle is to remove excess oxygen in the steel and add alloying elements according to the chemical composition requirements of smelting steel to ensure the physical and chemical properties of the steel.() answer: √
102. The smaller the specific gravity gap between steel and slag in steelmaking production, the more complete the slag is removed from the molten steel, and the less the content of inclusions in the steel.() answer:×
103. The conditions for judging the end point are three elements: carbon content of molten steel, temperature and basicity of slag.() answer:×
104. If the silicon content in molten iron is too high, too much lime will be added and the amount of slag will be large, which has no effect on phosphorus removal.() answer:×
105. Controlling the amount of slag from tapping can reduce the dephosphorization of ladle.() answer: √
106. Excessive loading will lead to increased splashing, difficult slagging and shortened service life of furnace cap.() answer: √ 107Single slag method is a method of adding slag forming agent into the furnace at one time during blowing.() answer:×
108. During furnace repair, do not pour too much furnace repair materials at one time to prevent weak sintering.() answer: √ 109The main purpose of gun lowering before the end point is to raise the temperature.() answer:×
110. Because the iron content in molten iron is the highest, iron oxidation is the main heat source of converter steelmaking.（）
answer:×111. The so-called temperature system refers to the control of the end temperature.() answer:×
112. The higher the MgO in the slag, the more favorable it is to protect the furnace lining.() answer:×
113. “Constant pressure changing gun” operation means that the working oxygen pressure is constant and the gun position changes in the smelting process.() answer: √
114. In order to increase the furnace life, the lower the tapping temperature, the more favorable.() answer: √
115. The amount of scrap added is determined according to the material balance data.() answer:×
116. Double slag method is a method of adding slag forming agent into the furnace in two batches in the smelting process.() answer:×
117. Too high gun position is easy to cause large spray, and too low gun position is difficult to slagging.() answer: √
118. In the early stage of blowing, if the flame at the furnace mouth comes up late and there is more red smoke, it indicates that the temperature in the early stage is low.() answer: √
119. The primary carbon drawing rate at the end of blowing is low, the number of post blowing increases, and the service life of furnace lining will be reduced by multiple furnace pouring.() answer: √
120. The purpose of tapping slag retaining is to prevent or reduce the high iron oxide final slag of the converter from flowing into the ladle during tapping.() answer: √
121. Furnace volume ratio is the ratio of effective volume of converter to metal loading.() answer:×
122. Due to the strong erosion ability of (FeO) to the furnace lining, when the oxidation of slag is too high, the service life of the furnace lining will be greatly reduced.() answer: √
123. When the end carbon content is the same, the end oxygen content of top bottom combined blown converter is lower than that of top blown converter.() answer: √
124. If the oxidation of slag is strong, the alloy absorption rate is high.() answer:×
125. The content of CO in converter gas can be as high as 60% ~ 80%.() answer: √
126. Alloying addition sequence: alloying alloy elements are added first and deoxidizing alloy elements are added later.() answer:×
127. After adding high melting point alloy to molten steel, the melting point of molten steel also increases.() answer:×
128. In order to ensure slag splashing and furnace protection, the lower R is, the better.() answer:×
129. Slag splashing should start when starting a new furnace.() answer:×
130. The end point control strictly stipulates the contents of C, P and s in molten steel, but does not require the tapping temperature.() answer:×

Calculation questions (35 questions)

1. It is known that there are 42 tons of molten iron, in which the content of Si is 0.50%, the content of Cao in lime is 86%, the content of SiO2 in lime is 2.5%, and the basicity r of slag is 3.2. What is the amount of lime added?
Slaking: lime addition = 2.14×0.50％/（86％-3.2×2.5％）×Three point two×one thousand×42=1843.692Kg
Answer: the amount of lime added is 1843.692kg.
2.50t converter, loading 55T, blowing for 13min, oxygen flow 13500nm3 / h, how much Nm3 is the oxygen consumption at this time?
Solution: known: q = 13500nm3 / h, t = 13min by: q = V / T
Obtained: v = QT = (13500 / 60)×13＝2925Nm3
Answer: the oxygen consumption is 2925nm3.
3. The total loading capacity of a converter is 55 tons (45 tons of molten iron, 10 tons of scrap + pig iron) and the tapping capacity is 48 tons. Try to calculate the blowing loss of the converter?
Solution: blowing loss of converter = (incoming metal material – tapping amount) / incoming metal material×100%＝(55－48)/55×100%＝12.7%
Answer: the blowing loss of the converter is 12.7%.
4. A converter plant was put into service four times in 2009, producing 2.4 million tons of steel, with an average steel output of 46 tons per furnace. What is the average furnace life of the converter plant?
Solution: total number of heats = total output / average tapping volume = 2400000 / 46 = 52174 (heats) average furnace age = total number of heats / furnace service number = 52174 / 4 = 13043 (heats)
A: the average furnace life of the converter plant is 13043 furnaces.
5. A converter smelts 55 heats of steel within 24 hours, of which the reheating time is 45 minutes and the time for hot metal and scrap is 30 minutes. Try to calculate the smelting cycle of the converter?
Solution: smelting cycle = total smelting time / number of smelting furnaces = (24)×60-45-30)/55＝24.82min
Answer: the smelting cycle of the converter is 24.82 minutes.
6. The tapping capacity is 100t and the oxygen content in molten steel is 700ppm. How much aluminum should be added to calculate the total deoxidation of molten steel?(keep one significant digit after the decimal point. The relative atomic mass of Al is 27 and the relative atomic mass of oxygen is 16)
Solution:
(1) The reaction formula is 2Al + 3 [O] = (Al2O3)
(2) Molten steel contains 0.07% (700ppm) [O], total oxygen content in 100t: 100×one thousand×0.07%=70（Kg）
(3) Calculate the amount of aluminum, and set the amount of aluminum as X: 2Al + 3 [O] = (Al2O3) 2×Two hundred and seventy-three×16×70（2×27）/x=（3×16）/105x=（2×Twenty-seven×70）/（3×16）x≈79（Kg）
A: about 79kg of aluminum needs to be added for full deoxidation of molten steel
7. It is known that the target carbon of a certain steel is 0.22-0.25%, manganese is 1.15-1.45% and silicon is 0.40-0.60%.Silicon manganese alloy contains carbon 2%, manganese 65%, silicon 17%, silicon 72%, manganese absorption rate is 85%, silicon absorption rate is 70%, carbon absorption rate is 90%.The transfer in volume of converter is 52 tons, the blowing loss is 10%, and the residual manganese at the end point is 0.05%.How many kilograms of silicon manganese and silicon iron should be added in the calculation?What is the amount of carburization after adding the alloy?
Solution: converter tapping amount = 52×(1-10%)＝46.8t
Addition amount of silicon manganese alloy = [(1.15% + 1.45%) / 2-0.05%]×forty-six point eight×1000/(65%×85%)≈1059kg
Silicon increment of silicon manganese alloy = 1.059×17％×70％/46.8×100％＝0.27％
Ferrosilicon addition = [(0.40% + 0.60%) / 2-0.27%]×forty-six point eight×1000/(72%×70%)≈214kg
Silicon manganese carburizing amount = 1.059×2%×90%/46.8×100%＝0.04%
Answer: the addition amount of silicon manganese alloy is 1059kg and that of ferrosilicon alloy is 214kg;After adding the alloy, the carburization amount is 0.04%.
8. For smelting Q235 steel, the tapping amount is 50 tons, the addition amount of Fe Mn alloy is 420kg, the composition Mn of the finished product is 0.45%, and the remaining Mn at the end of molten steel is 0.45%08%, and the Mn content of Fe Mn is 65%. What is the absorption rate of Fe Mn in this furnace steel?
Solution: Ferromanganese absorption rate = (finished product composition Mn% – residual manganese%)×Tapping amount / (alloy content%)×Alloy addition amount)×100%＝(0.45%-0.08%)×50000/(65%×420)×100%＝67.8%
A: the Fe Mn absorption rate of molten steel in this furnace is 67.8%.
9. It is known that the element percentage (XI) in a molten steel is: carbon 0.11%, silicon 0.21%, manganese 0.42%, phosphorus 0.02%, sulfur 0.03%, copper 0.06%, and the rest is not counted.The influence value (△ Ti) of 1% of each element on liquid steel solidification is: carbon 90, silicon 6.2, manganese 1.7, phosphorus 28, sulfur 40, copper 2.6;The melting point of pure iron is 1538 ℃.Try to calculate the liquidus temperature of the molten steel (liquid T)?
Solution: liquid t = 1538 －∑ (XI)×△ti)＝1538－(0.11%/1%×90＋0.21%/1%×6.2＋0.42%/1%×1.7＋0.02%/1%×28＋0.03%/1%×40＋0.06%/1%×2.6)＝1524℃
Answer: the liquidus temperature of the molten steel is 1524 ℃.
10. The converter is charged with 45t molten iron, and the manganese content is 0.40%;Scrap steel 10t, manganese content 0.50%;Manganese content in bulk material is ignored.The amount of molten steel at the end point is 46t, and the residual manganese is 0.08%ω(MnO) = 4.0%, calculated by manganese balance method?(the atomic weight of Mn is 55 and that of O is 16)
Solution: set the slag amount asχTons.
Terminal slagω(MnO) = 4.0%, thenω（Mn）=4.0%×55/（55+16）=3.1%。
Manganese source amount = manganese amount of molten iron belt + manganese amount of scrap steel belt = 45×100×0.40%+10×one thousand×0.50% = 230kg manganese expenditure = manganese in molten steel + manganese in slag = 46×one thousand×0.08%+1000×3.1%χAccording to the law of conservation of mass, manganese source = manganese expenditure.230=46×one thousand×0.08%+1000×3.1%χχ=6.23t
Answer: the amount of slag is 6.23t.
11. Set the slag amount as 10% of the loading amount, the lining erosion amount as 1% of the loading amount, and the lining MgO amount as 40%;Hot metal composition Si = 0.6%, P = 0.09%, s = 0.04%;Final slag requirement (MgO) = 10% and alkalinity is 4.0. Calculate the amount of lime and dolomite to be added?Known lime composition: Cao = 88%, MgO = 1.7%, SiO2 = 0.4%;Dolomite composition: Cao = 40%, MgO = 35%, SiO2 = 3%.
Solution:
(1) Amount of dolomite to be added:
W White = 10%×10%×1000/35%＝28.6kg/t
(2) Amount of dolomite converted from MgO in slag after lining erosion:
W lining = 1%×40%×1000/35%＝11.4kg/t
(3) Amount of dolomite converted by lime into MgO:
W stone = 2.14×0.6%×Four×one thousand×1.7%/[35%×(88%-4×0.4%)]=2.89kg/t
(4) Actual dolomite addition:
W White ‘= 28.6-11.4-2.89 = 14.31kg/t
(5) Cao converted lime amount brought into slag by dolomite:
fourteen point seven×(40%-4×3%)/(88%-4×0.4%)＝4.64kg/t
(6) Actual amount of lime to be added:
W stone ‘= 2.14×0.6%×Four×1000/(88%-4×0.4%)-4.64=54.8kg/t
Answer: the amount of dolomite actually added is 14.7kg/t and the amount of lime is 54.6kg/t.
12. The amount of slag is 13%, the content of FeO in slag is 11%, and the content of Fe2O3 is 2%. Try to calculate the iron oxidation loss per ton of steel slag?
Solution: 1000×13%(11%×56/72+2%×112/160)=13kg
Answer: the iron oxidation loss per ton of steel slag is 13kg.
13. [Si] = 0.50% in molten iron, lime composition: Cao = 89%, SiO2 = 2%, slag alkalinity r = 3.5, calculate the amount of lime per ton of molten iron?
Slaking: lime addition = [(2.14)×[Si%])/(CaO%-R×SiO2%)]×R×1000＝(2.14×0.50%)/(89%-3.5×2%)×Three point five×1000 = 45.67kg/t molten iron
Answer: the lime consumption per ton of molten iron is 45.67kg.
14. Calculate the amount of converter slag (T) according to the manganese balance?(two decimal places are reserved).
Known: 1) iron content: 145t, Mn content: 0.20%;2) Scrap steel quantity: 10t, Mn content: 0.45%;3) Water content of steel: 140t, residual Mn content: 0.10%;4) Final slag: Mn: 1.2%.(Mn brought in by bulk materials is ignored) solution: set the slag amount as X tons.
Manganese input = 145×0.20%＋10×0.45%＝0.335(t)
Manganese production = 140×0.10%＋X·1.20%＝0.140＋1.2%X0.335＝0.140＋1.2%XX＝(0.335－0.140)÷1.2%X＝16.25(t)
A: the amount of converter slag is 16.25 tons.
15. The loading capacity of the converter is 120t, the blowing time of each furnace is 15min, and the oxygen consumption (standard state) of each furnace is 5500m3. Calculate the oxygen flow and oxygen supply intensity?
Solution: v = 5500m3, t = 15min, q = V / T = 5500 ÷ 15×60=22000m3/hI=Q/T=22000÷120÷60=3.06m3/min.t
Answer: the oxygen flow and oxygen supply intensity are 22000m3 / h and 3.06m3/min. T respectively.
16. It is known that: the amount of slag (Q slag) is 4T, the required content of magnesium oxide in slag (mg requirement%) is 9%, the furnace charge etching makes the slag contain magnesium oxide (MgO raw slag%) 2%, and the magnesium oxide ball contains magnesium oxide 70% (MgO magnesium ball%). What is the addition amount of magnesium oxide ball in each furnace?(kg to integer)
Solution: addition amount of magnesium oxide ball = [(MgO requirement% – MgO raw slag%) / MgO magnesium ball%]×Q slag = (9% – 2%) / 70%×Four×1000＝400(kg)
Answer: the addition amount of magnesium oxide balls per furnace is 400kg.
17. Calculate how much heat needs to be absorbed by heating 1 ton of scrap from 25 ℃ to 1650 ℃?It is known that the melting temperature of scrap steel is 1510 ℃, and the latent heat of scrap steel melting is 271.7 kJ / kg
The average heat capacity of solid scrap is 0.7 kJ / degree · kg, and the average heat capacity of liquid steel is 0.84 kJ / degree · kg
Solution: Q suction = 1000×｛(1510－25)｝×0.7＋271.7+(1650－1510)×0.84｝＝1428800kj
Answer: need to absorb heat 1428800kj.
18. The chemical composition of a steel is as follows:
C：0.20%；Si：0.25%；Mn：0.45%；P：0.02%；S：0.03%；Cu：0.20%；Other components are not included.The influence value of each 1% content of various elements on the solidification temperature of liquid steel is: C: 90;Si：6.0Mn：1.7P：28S：40Cu：2.6
The freezing point of pure iron is 1538 ℃, and the liquidus temperature in Benxi steel is calculated?(integer digits reserved)
Solution: 1538 – (0.2×90＋0.25×6＋0.45×1.7+0.020×28＋0.030×40+0.20×2.6)＝1515℃
Answer: liquidus temperature of this steel is 1515 ℃.
19. Composition target of a certain steel: silicon (Si target%) 0.28%, manganese (Mn target%) 0.5%, residual manganese in molten steel (Mn residual%) 0.05%, and steel water volume (m) 37 tons.Ferrosilicon and silicon manganese alloys are required to be added. It is known that ferrosilicon contains 74.1% silicon (Si ferrosilicon%) and the absorption rate is 74.1%（η80% Si%, 65.8% Mn (Mn Si Mn%), 18.5% Si Si Mn), and its absorption rate（ηMn%)90%。Try to calculate the addition amount of the two alloys?(calculated to kilogram, and the percentage is kept to three decimal places) solution:
(1) Manganese shall be prepared first, and the addition amount of silicon manganese shall be calculated
QMN = (Mn target% – Mn residual%) / (Mn silicomanganese%×ηMn%)×M＝(0.5%-0.05%)/(65.8%×90%)×Thirty-seven×1000＝281kg
(2) Calculate the silicon content of silicon manganese strip (Si silicon manganese%) Si silicon manganese = qmnsi silicon manganeseηSi/M＝281×18.5%×80%/(37×1000)＝0.112%
(3) Calculation of ferrosilicon addition
QSI = (Si target Si Si Mn) / (Si Si Fe%×ηSi)×M＝(0.28%-0.112%)/(74.1%×80%)×Thirty-seven×1000＝105kg
Answer: the addition amounts of MnSi and FeSi are 281kg and 105kg respectively.
20. For smelting 20MnSi, the charging amount of this furnace is 140t molten iron, 10t scrap steel, blow loss is 10%, the alloy composition used is “ferrosilicon: containing Si: 75%; FERROMANGANESE: Containing Mn: 70%, and the residual Mn at the smelting end point is 0.10%. The recovery rate of alloy silicon is 80%, and the recovery rate of alloy manganese is 85%. The addition amount of ferrosilicon and ferromanganese alloy of this furnace steel is calculated according to the medium limit composition (Mn: 1.40%; Si: 0.60%). (kg)? (keep integer) solution:
(1) Steel quantity = (140 + 10)×90%＝135(t)
(2) Ferromanganese addition = (1.40% – 0.10%) / (70%)×80%）×One hundred and thirty-five×1000 ＝ 2950 (kg / furnace)
(3) Ferrosilicon addition = 060% / (75%)×80%）×One hundred and thirty-five×1000 = 135 (kg / furnace)
Answer: 135 kg of ferrosilicon and 2950 kg of ferromanganese are added to this furnace.
21. When smelting 16Mn steel, if Mn Si, Al Ba Si and Ca Si alloys are used for deoxidization and alloying, Al BA – Si0 shall be added per ton of molten steel75kg, CA Si alloy 0.70kg, calculate the addition amount of Mn Si alloy and Fe Si alloy?Solution: first calculate the addition amount of Mn Si: (according to Mn)
Mn Si alloy addition = (1.40% – 0.16%)×1000/(68.5%×85%)=21.3kg/t
Silicon increase of Mn Si alloy = (21.3)×18.4%×80%/1000)×100%=0.313%
Al BA – Si0 per ton of molten steel75kg, 0.70kg silicon increase of Ca Si alloy: Al BA – Si silicon increase = (0.75×42%×80%/1000)×Silicon increment of 100% = 0.025% CA Si alloy = (0.7×58%×80%/1000)×100% = 0.032% due to insufficient Si content, additional Fe Si content: Fe Si alloy addition = (0.40% – 0.313% – 0.025% – 0.032%)×1000/(75%×80%)=0.5kg/t
Answer: 21.3kg/t Mn Si alloy and 0.5kg/t Fe Si alloy shall be added per ton of molten steel.
22. It is known that the silicon content of molten iron is 0.85% and the phosphorus content is 0.2%;The content of Cao in lime is 89%, the content of SiO2 is 1.2%, and the content of MgO is 3.0%;The content of Cao, MgO and SiO2 in dolomite is 32%, 21% and 1.3%, respectively;The alkalinity of final slag is 3.5, the content of MgO is 6%, and the amount of slag is 15% of the loading amount;The erosion amount of furnace lining is 0.9% of the loading amount, the content of MgO in furnace lining is 37%, and the content of Cao is 55%.Try to find the addition amount of dolomite and lime per 1000kg of molten iron?
Solution:
(1) Demand for lime:
Lime demand = (1000)×0.85%×60/28×3.5)/(89%-3.5×0.2%)＝75Kg
(2) Calculate the addition amount of dolomite:
Dolomite demand = (1000)×15%×6%)/21%＝43Kg
The amount of MgO brought in by lime converted into dolomite is 75×3.0/21%＝11Kg
The quantity of MgO converted into dolomite brought into the furnace lining is 1000×0.9%×37% / 21% = 16KG, so the addition amount of dolomite = 43-11-16 = 16KG
(3) Calculate the addition amount of lime:
The amount of Cao brought in by dolomite converted into lime is: (16×32%)/(89%-3.5×1.2%) = 6kg Cao brought in by furnace lining is converted into lime, and the quantity is 1000×0.9%×55%/(89%-3.5×1.2%) = 6kg, so the addition amount of lime = 75-6-6 = 63kg
It can be seen from the above that when dolomite slagging process is adopted in converter steelmaking, the amount of dolomite is about one quarter of that of lime. Answer: the addition amount of dolomite and lime per 1000kg of molten iron is 16KG and 63kg respectively.
23. Calculation of slag magnesium oxide.
It is known that the amount of slag (Q slag) is 7T, the required content of magnesium oxide (Q requirement%) is 9%, the lining erosion makes the slag contain magnesium oxide (MgO raw slag%) 2%, and the dolomite contains magnesium oxide (MgO dolomite%) 18%. Calculate the addition amount of dolomite (Q dolomite) kg per furnace?(kg to integer)
Solution: Q dolomite = (MgO requirement% – MgO raw slag%)×Q slag / MgO dolomite% Q dolomite = 2722 (kg)
A: 2722 kg of dolomite is required.
24. Try to calculate the silicon distribution of molten iron in the new converter?
It is known that the silicon content of hot metal (Si hot metal%) is 0.80%, the silicon content of ferrosilicon (Si ferrosilicon%) is 74%, and the loading capacity of hot metal is 90 tons. It is required that the silicon content of hot metal after preparation (Si requirement%) is 1.2%, and the dosage of ferrosilicon (Q kg).
Solution: q = (Si requires% – Si molten iron% / Si ferrosilicon%)×FQ = 486 (kg)
A: the dosage of ferrosilicon alloy is 486kg.
25. Calculate the alloy addition and alloy carburization for smelting 16Mn steel?
It is known that the medium limit of 16Mn steel specification: mn-1.40%, si-0.40%, and the remaining mn015%, and the remaining Si is the trace.Silicon manganese alloy and silicon iron deoxidation alloying are adopted.Silicon manganese alloy composition: mn70%, sil8%, C16%, ferrosilicon composition: si75%, alloy recovery? Mn＝85%，Si＝80%，C＝90%
Solution: first, use silicon manganese to match manganese to the middle limit
(1) Silicon manganese addition = (1.4% – 0.15%) / (70%)×85%）×1000 = 21kg / T steel
(2) Silicon manganese increase Si = silicon manganese addition×Silicon manganese containing silicon×?Si/1000＝21×18%×80% / 1000 = 0.30% (3) in addition, ferrosilicon shall be added to the middle limit of the finished product
Ferrosilicon addition = (0.40% – 0.30%)/（ηSi×75%)×100
＝（0.40%-0.30%）/（80%×75%）×1000 = 1.67kg/t steel
(4) Alloy increase △ C = silicon manganese addition×Carbon content of silicon manganese×c/1000＝21×1.6%×90%/1000＝0.03%
(5) Answer: the addition amount of silicon manganese and silicon is 21kg / T steel and 1.67kg/t steel respectively, and the carburization amount of alloy is 0.03%.
26.Calculate the tapping temperature of Q235 steel?
Known:
(1) Chemical composition of Q235 steel (%):
(2) Decrease of freezing point of pure iron per 1.0% element (℃):
The combined action of H2, N2 and O2 in steel reduces the freezing point by 7 ℃.
(3) Temperature drop of molten steel from tapping to continuous casting: 80 ℃.
(4) Temperature drop of molten steel from ladle to tundish during pouring: 40 ℃.
(5) Superheat requirement of molten steel in tundish: 30 ℃.
Solution: according to the formula t = Liquid T + △ Tl + △ T2 + △ t3t – liquidus temperature of the cast steel.TL – temperature drop of molten steel during pouring
T2 – temperature drop of molten steel from tapping to pouring, T3 – superheat of molten steel in tundish according to known conditions: t liquid = 1538 – ∑△ t×j＝1538－(0.2×65+0.2×8+0.4×5+0.03×30+0.02×25+7)＝1513℃
T out = 1513 + 80 + 40 + 30 = 1663 ℃
Answer: the tapping temperature of Q235 steel is 1663 ℃.
27.A factory produces 100 furnaces of steel per day, the output of each furnace is 40t, and the nitrogen consumption per ton of steel slag splashing is 10m3. What is the capacity of nitrogen press?
Solution: (100)×50×10)/24＝1666m3/h
Answer: the capacity of nitrogen compressor should be 1666m3 / h.
28. The MgO content in the final slag of a plant is 4%. After slag splashing, the MgO content in the slag needs to be increased to 8%. It is known that the MgO content in the lightly burned magnesium ball is 70%. How much magnesium ball should be added per ton of steel?(the amount of steel slag per ton is calculated as 100kg, and the increased amount of slag after adding magnesium ball is not counted)
Solution: 100×(8%-4%)/0.7＝5.7kg
Answer: 5.7kg magnesium balls shall be added per ton of steel.
29. The molten iron loading of oxygen top blown converter in a plant is 31t, the scrap steel is 9t, and the steel tapping is 36.6t. How much is the blowing loss?
Solution: blow loss = (loading capacity – tapping capacity) / loading capacity×100% = (31 + 9 － 36.6) / (31 + 8)×100%=8%
Answer: blow loss is 8%.
30. In the first quarter, the amount of steel in a steel plant was 824000 tons, and the output of qualified steel was 795000 tons: the amount of scrap was 5000 tons. What is the billet yield?
Solution: total billet output = 79.5 + 0.5 = 800000 tons
Billet yield = 80 / 82.4×100%=97.08%
A: the billet yield is 97.08%.
31. It is known that the Si content of low phosphorus molten iron is 0.8%;The CaO content of lime is 80%, and the SiO2 content is 5%;The basicity r of slag is required to be controlled at 3.0.Q: what is the amount of lime added when the amount of molten iron is 30t?(it is known that the ratio of molecular weight of SiO2 to atomic weight of Si is 2.14)
Solution: ê o = ê o-r×SiO2＝80%-3.0×5%＝65%
(1) Lime addition = 2.14×0.8%×3×1000/65%＝79.0(kg/t)
(2) The amount of lime added to the furnace steel = 79.0×30 = 2370 (kg) answer: when the amount of molten iron is 30t, the amount of lime added is 2370kg.
32. A steel plant has an annual output of 2 million tons of qualified steel, the consumption of molten iron is 2 million tons / year, and the amount of scrap steel is 10% of the amount of molten iron. Calculate the steel material consumption of the plant (kg / T)?
Solution: steel material consumption = (200 + 200)×10%)/200×1000＝1100kg/t
A: the steel material consumption of the plant is 1100kg / T steel.
33. It is known that the chemical composition of 45# steel is C = 0.45%, Si = 0.27%, Mn = 0.65%, P = 0.02%, s = 0.02%;The influence values of the following elements on the freezing point of pure iron are as follows (unit ℃): C = 65, Si = 8, Mn = 5, P = 30, s = 25;Other elements reduce the freezing point of pure iron to 7 ℃, and the freezing point temperature of pure iron is 1538 ℃.Calculate the freezing point temperature of the steel?
Solution: t coagulation = 1538 – (∑)ΔT.Δx)-7＝1538-(0.45×65+0.27×8+0.65×5+0.02×30+0.02×25+7)＝1495℃
Answer: the freezing point temperature of this steel is 1495 ℃.
34. The converter smelts Q235 steel, in which the tapping capacity is 25t and the residual manganese at the smelting end point is 0.15%. The deoxidizing alloy adopts silicon barium (the addition amount is determined as 80kg / furnace). Ferrosilicon and ferromanganese are added in the ladle, in which the content of silicon barium and silicon is 70%, the absorption rate of silicon is 85%, the content of silicon iron and silicon is 75%, the absorption rate of silicon is 75%, the content of manganese in ferromanganese is 65% and the absorption rate of manganese is 80%.What is the alloy amount of ferrosilicon and ferromanganese that should be added to the steel of this furnace?(Note: the composition of Q235 is 0.12% ~ 0.30% for Si and 0.30% ~ 0.70% for Mn)
Solution: Ferromanganese addition = (0.50% – 0.15%)×Twenty-five×1000/(65%×80%)＝168(kg)
Silicon increase after adding silicon and barium = (80×70%×85%×100%)/(25×1000) = 0.19% ferrosilicon addition = (0.21% – 0.19%)×Twenty-five×1000/(75%×75%)＝9.0(kg)
Answer: 9.0kg ferrosilicon and 168kg ferromanganese alloy should be added to the steel of this furnace.
35. The target composition of a certain steel is silicon (Si target%) 0.28%, manganese (Mn target%) 0.5%, residual manganese (Mn residual%) 0.05% in molten steel and 73 tons of steel water (m). Ferrosilicon and silicon manganese alloys are required to be added.It is known that ferrosilicon contains 74.1% silicon (Si, Fe%), 80% absorption rate (Si%), and silicon manganese contains 18.5% silicon (Si, Mn)（η80% Si%, 65.8% Mn, 65.8% Si（ηMn%) 90%, what is the addition amount of the two alloys?(the last three digits are reserved for the calculated percentage)
Solution: calculate the addition of silicon and manganese (QMN)
QMN = [Mn target% – Mn residual%] / Mn silicomanganese%×ηMn%]×M＝[(0.5%-0.05%)/(65.8%×90%)]×Seventy-three×1000＝555(kg)
Calculate the silicon content of silicon manganese (Si silicon manganese%)
Si Si Mn = (QMN)×Si Si Mn%×ηSi/M)×100%＝(555×18.5%×80%/73×1000)×100%＝0.113%
Calculate ferrosilicon addition (QSI)
QSI = [(Si target Si Si Mn) / Si ferrosilicon×ηSi]×M＝[(0.28%-0.113%)/74.1%×80%]×73×1000＝206(kg)
Answer: the addition amount of silicon manganese and ferrosilicon is 555kg and 206kg respectively.

Source: China Custom Flanges Manufacturer – Yaang Pipe Industry (www.epowermetals.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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