Type: UNS N08904 Seamless Pipe
Material: 904L (UNS N08904/W.Nr. 1.4539)
- Pipe OD: 141 MM; WT: 9.53 MM)
Standard: ASTM B677
Length: Normally fixed length 6m, can as per customer’s requirement.
End: Beveled End,Plain End
What is 904L (UNS N08904)?
UNS N08904, commonly known as 904L with its DIN equivalent W.Nr. 1.4539, is a low carbon super austenitic stainless steel. It has superior corrosion resistance to that of conventional Cr-Ni stainless steels such as SS316L and SS317L resulting from the deliberate addition of copper content. Although the 904L stainless steel has limited use with hydrochloric acids, it has high resistance to pitting corrosion in chloride solutions, high resistance to both crevice and stress-corrosion cracking. The grade is non-magnetic and has excellent formability and weldability, as well as good toughness in cryogenic temperatures. 904L stainless steels have greater resistance to precipitation of ferrite and sigma phases on cooling and welding. The low carbon content reduces the risk of intercrystalline corrosion on cooling or welding processes. This super austenitic stainless steel is widely used in chemical processing, oil & gas, and pharmaceutical industries.
Grade specifications of grade 904L
Chemical Composition of 904L (UNS N08904/W.Nr. 1.4539)
|The Chemical Composition of 904L, %|
Mechanical Properties of 904L (UNS N08904/W.Nr. 1.4539)
Density: 8.0g/cm3. Tensile strength: σB ≥ 520mpa. Elongation: δ ≥ 35%
Physical Properties of 904L (UNS N08904/W.Nr. 1.4539)
|Density||Specific Heat||Thermal Conductivity||Thermal Expansion||Modulus Elasticity||Electrical Resistivity|
Product Forms and Relative Standards of 904L (UNS N08904/W.Nr. 1.4539)
|904L plates, 904L sheets & strips||ASATM A240, A480|
|904L bars, 904L rods, 904L billets||ASTM A276, A479|
|Forgings (904L flanges, 904L pipe fittings, 904L Baffle, F904L Forged Ring, 904L Tube Sheet)||ASTM A182, A484|
|904L welded and seamless pipes/ Tubes||ASTM A312, A269|
|904L butt welding pipe fittings||ASTM A403, ASME B16.9|
Production chart of UNS N08904 Seamless Pipe
1. Cold Rolling (Cold drawn) Pipe Production Processes
Round Pipe Billet → Heating → Perforation → Head → Annealing → Pickling → Oil (Copper) → Multi Pass Drawing (Cold Rolling) → Billet → Heat Treatment → Straightening → Water Pressure Test → Marking → Storage
2. Hot Rolling Pipe Production Processes
Round Pipe Billet → Heating → Perforation → Three Roll Skew Rolling, Continuous Rolling or Extrusion → Off Pipe → Sizing (Or Reducing Diameter)→ Cooling → Billet → Straightening → Water Pressure Test ( Or Flaw Detection) → Marking → Storage
3. Longitudinal Welding (Straight Seam Welding) Pipe Production Processes
Including ERW, EFW.
Steel pipe wall thickness (ASME B36.10 & B36.19)
|Nominal Pipe Size||Outside diameter||Wall thickness|
|SCH 5S||SCH 10S||SCH STD (40S)||SCH XS||SCH 160S||SCH XXS|
|The dimensions are in millimeters|
|Sources : ASME B36.19, ASME B36.10|
PERMISSIBLE VARIATIONS IN OUTSIDE DIAMETERA AND WALL THICKNESS Permissible Variations In Outside Diametera And Wall Thickness
- (1) Pipe and tube having a nominal wall thickness fo 3% or less of the nominal ouside diameter. The mean outside diameter shall conform to the permissible variations of Table 3 and individual measurements (including ovality) shall conform to the plus and minus values of the table, with the values increased by 0.5% of the nominal ouside diameter.
- (2) The mean ouside diameter for pipe and tube over 4 1/2 in. (114 mm) in outside diameter with a nominal wall thickness greater than 3% of the nominal ouside diameter shall conform to the permissible variations of this table, and individual measurements shall not exceed twice the permissible variations of the table.
|Specified Outside Diameter||Permissible Variations|
|Outside||Thickness of Specified||Thickness of Specifined|
|Diameter, in (mm)||Average Wall, %||Minimum Wall, %|
|Cold-Worked Pipe and Tube:|
|0.500(13) to 5/8(16), excl||0.005(0.13)||0.005(0.13)||15||15||30||0|
|5/8(16) to 1 1/2(38), incl||0.0075(0.19)||0.0075(0.19)||10||10||20||0|
|Over 1 1/2(38) to 3 1/2(89), incl||0.010(0.25)||0.010(0.25)||10||10||22||0|
|Over 3 1/2(89) to 4 1/2(114), incl||0.015(0.38)||0.015(0.38)||10||10||22||0|
|Over 4 1/2(114) to 3 1/2(152), incl||0.020(0.51)||0.020(0.51)||12.5||12.5||25||0|
|Over 6(152) to 6 1/2(168), incl||0.25(0.64)||0.25(0.64)||12.5||12.5||25||0|
|Hot-Finished Tube A,B:|
|1 1/2(38.1) to 5 1/2(139.7), excl||0.031(0.79)||0.031(0.79)||12.5||12.5||28.5||0|
|5 1/2(139.7) to 9 1/2(234.5) incl||0.047(1.19)||0.047(1.19)||12.5||12.5||28.5||0|
- A. The wall thickness tolerances for hot-finished tubes includeseccentricity tolerance up to ±12.5%.
- B. For hot-finished 5 in. (127.0mm) and under in outside diameter, the tolerances on the ouside diameter apply for individual measurements and include ovality. For tubes over 5 in. ion outside diameter, the mean ouside diameter shall comform to the permissible variations of this table andindividual measurements shall not be twice the permissible variations for this table.
Processing performance of 904L
Like general stainless steel, 904L can be welded in a variety of ways. The most commonly used welding method is manual arc welding or Sui Xing gas shielded welding. The welding rod or wire metal is based on the composition and purity of the base metal, and the content of molybdenum is higher than that of the base metal. Preheating is generally not required before welding, but in cold outdoor operation, in order to avoid condensation of water vapor, the joint or adjacent area can be heated evenly. Note that the local temperature should not exceed 100 ℃, so as not to cause carbon accumulation and intergranular corrosion. Small linear energy, continuous and fast welding rate should be adopted during welding. Generally, no heat treatment is required after welding. If heat treatment is required, it shall be heated to 110 – 1150 ℃ and then cooled rapidly.
Supporting welding materials: welding rod (E385-16/17), welding wire (ER385).
The machining characteristics of 904L are similar to other austenitic stainless steels, and there is a trend of tool sticking and work hardening in the process of machining. It is necessary to use positive rake angle cemented carbide tools and use vulcanized and chlorinated oil as cutting coolant. The equipment and process shall be based on the premise of reducing work hardening. Slow cutting speed and feed amount should be avoided in the cutting process.
Grade 904L stainless steels offer good oxidation resistance. However, the structural stability of this grade collapses at high temperatures, particularly above 400°C.
Grade 904L stainless steels can be solution heat-treated at 1090 to 1175°C, following by rapid cooling. Thermal treatment is suitable for hardening these grades.
Grade 904L stainless steels are high purity steels with low sulphur content. They can be machined using any standard methods. These grades can be readily bent to a small radius under cold conditions. Although subsequent annealing is not required in most cases, it should be carried out when the fabrication is performed under severe stress corrosion cracking conditions.
Application of 904L
904L alloy is a multi-purpose material, which can be applied in many industrial fields:
- Petroleum and petrochemical equipment, such as reactors in petrochemical equipment.
- Sulfuric acid storage and transportation equipment, such as heat exchanger, transportation pipeline, etc.
- The main parts of FGD device in power plant are: tube sheet, absorber body, flue, baffle, internals, spray system, etc.
- Scrubber and fan in organic acid treatment system.
China Alloy Steel Pipe Manufacturer www.epowermetals.com offers ASTM B677 UNS N08904 Seamless Pipe, 141*9.53*1000MM, HT: 192-804.