China piping solution supplier: www.epowermetals.com | Email: sales@epowermetals.comTel: +8618267732328

A Comprehensive Guide to Nickel-based Super Alloy: Hastelloy X (UNS NO6002/W.Nr 2.4665)

Few materials like nickel-based superalloys in advanced material engineering can combine strength, corrosion resistance, and versatility. This comprehensive guide deeply explores the complexity and distinctive features that make Hastelloy X a true miracle of modern metallurgy.

What is Hastelloy X?

Hastelloy X, also known as “Alloy X”, is designated as UNS N06002 or W.Nr 2.4665. It is a nickel-chromium-iron-molybdenum alloy that possesses an exceptional combination of oxidation resistance, fabricability, and high-temperature strength. Hastelloy X has also been found to be exceptionally resistant to stress-corrosion cracking in petrochemical applications and resistant to carburization and nitriding. Hastelloy X (UNS N06002) is mainly made of chromium and a nickel-based superalloy with high iron content strengthened by molybdenum solid solution. It has good anti-cultivation and corrosion resistance, moderate durability and creep strength below 900℃, cold and hot working formability and welding The performance is good. Used in the manufacture of combustion chamber parts and other high-temperature parts of aero-engines, long-term use below 900 ℃, short-term working temperature up to 1080 ℃. The main products supplied are plates, strips, tubes, bars, forgings, ring parts and precision castings.

Unveiling the Origins

Hastelloy X, a member of the renowned
Hastelloy family, was conceived with an unwavering commitment to surmount the
limitations of conventional alloys. Haynes International Inc. developed this
alloy to thrive in the most unforgiving environments, such as high-temperature
combustion chambers, gas turbine engines, and industrial furnace applications.

Chemical Composition Requirements of Hastelloy X

The Chemical Composition of Hastelloy X, %
Ni balance
Cr 20.5-23.0
Fe 17.0-20.0
Mo 8.0-10.0
Co 0.5-2.5
W 0.20-1.00
C 0.05-0.15
Mn ≤1.00
Si ≤1.00
P ≤0.040
S ≤0.030

Typical Physical Properties of Hastelloy X

Density

Melting Range

Specific Heat

Thermal Conductivity

Electrical Resistivity

g/cm3

°C

J/kg.k

W/m.k

µΩ·m

8.22

1260-1355

486

9.1

1180

Product Forms and Standards of Hastelloy X

Product Form Standard
Bar ASTM B572
Plate, sheet and strip ASTM B435, B906
Seamless pipe and tube ASTM B622
Welded pipe ASTM B619, B775
Welded tube ASTM B626, B751
Welded pipe fitting ASTM B366
Billet and bar for reforging ASTM B472

*The mechanical properties of Hastelloy X materials vary according to different forms and heat treatment conditions.

The physical and chemical properties of Hastelloy X (N06002)

The melting temperature range of Hastelloy X (N06002): 1295-1381℃. 

  • Hastelloy X (N06002) alloy thermal conductivity: see Table 2-1.
  • Hastelloy X (N06002) alloy specific heat capacity: Table 2-2. 
  • Hastelloy X (N06002) alloy linear expansion coefficient: see Table 2-3. 
  • Thermal diffusivity of Hastelloy X (N06002) alloy castings: see Table 2-4. 
  • Density of Hastelloy X (N06002): ρ=8.28g/cm3 . 
  • Hastelloy X (N06002) electrical properties: the resistivity is shown in Table 2-5. 
  • Hastelloy X (N06002) magnetic properties: the alloy is non-magnetic. 
  • Hastelloy X (N06002) chemical properties: see Table 3-1.
  • Hastelloy X (N06002) oxidation resistance: the oxidation rate of the alloy after 100h test in air medium is shown in Table 2-6. 
  • Hastelloy X (N06002) mechanical properties: The mechanical properties of different varieties specified in HastelloyX technical standards are shown in Table 3-1. 

Table 2-1

θ/℃ 100 200 300 400 500 600 700 800 900

λ/(W/(m·℃))

13.38 17.97 20.27 22.40 24.62 26.79 29.05 31.14 33.44

Table 2 – 2 

θ/℃ 17 100 200 280 408 500 700 800 900
c/(J(kg·℃)) 372.6 372.6 389.4 456.4 427.1 452.2 515.0 535.9 561.0

Table 2- 3

θ/℃ 20-100 20-200 20-300 20-400 20-500 20-600 20-800 20-900
α/10 -6 ℃ -1 12.1 12.5 13.4 14.0 14.3 14.8 15.8 16.1

Table 2-4

θ/℃ 24 100 300 400 500 600 700 800 900
Q/(10 -6 m 2 /S)) 2.78 3.06 3.68 3.64 4.36 4.32 4.38 4.91 5.23

Table 2-5

θ/℃ 100 200 300 400 500 600 700 800 900
p/(10-6Ω.M)) 1.18 1.20 1.21 1.22 1.24 1.25 1.26 1.27 1.29




Table 2-6

θ/℃ 700 800 900 1000 1100
Oxidation rate/(g/(m 2 ·h)) 0.0023 0.060 0.117 0.200 0.611

Table 3-1

Variety Tensile performance at room temperature σP0.2/MPa 815 lasting performance σb/MPa Other properties
not less than δ5/% σ/MPa t/h δ5/%  Rockwell hardness
Cold-rolled sheet, cold-rolled strip, cold-drawn pipe, bar, ring, precision casting 310  725  35  110  24-  8.0  Bending 180° 
310  760 30       Bending 180° 
310  690  25        Hydraulic, flaring 
275  690  30  105  24-  10.0  HBS≤241 
275  690  30  105  24-  10.0  HBS≤241 
200 380 10 HBS≤96

① Room temperature tensile strength of strip with δ<0.25mm σb ≥725MPa, δ5 ≥25%. 
The σb ≥240MPa and δ5 ≥12 % of the precision casting at 815℃ . After 800℃, 50h, air cooling, (Rockwell hardness) HRC≤24. 

Alloy structure of Hastelloy X (N06002)

  • (1) The structure of the alloy in the solid solution state is an austenite matrix with a small amount of TiN and M6C carbides. After long-term aging at 700-900°C, the main precipitated phases are M12C and M3B2 , along with trace μ phase and L phase. A small amount of σ phase appeared after aging at 700°C for 200 hours, but there was no σ phase after aging at 800°C, and a trace amount of M23C6 was precipitated , sometimes a trace amount of L phase appeared. Therefore, the alloy shows a certain degree of age hardening after long-term aging, which reduces the plasticity and the high-temperature strength. 
  •  (2) The technical standard of cold-rolled sheet stipulates that the grain size of cold-rolled sheet in the supply state should be in the range of 4-8. 

Alloy process performance and requirements of Hastelloy X (N06002)

1. HastelloyX alloy forming properties:

The alloy has good cold and hot forming properties. The forging heating temperature is 1170℃±10℃, and the final forging temperature is not lower than 950℃; the slab hot rolling heating temperature is 1150℃±10℃, and the final rolling temperature is not lower than 850℃; the ring hot rolling heating temperature is 1170℃±10℃ . The high temperature tensile ductility of the alloy is shown in Figure 5-1.Figure 5-2 shows the recrystallization curve of high temperature upsetting sample after solution treatment at 1180℃ for 45min. 

2. HastelloyX welding performance:

This alloy has good welding process performance and can be welded by argon arc welding, seam welding and spot welding. HHastelloyX or HGH3113 welding wire is recommended for argon arc welding. 

(1) For HastelloyX manual argon arc welding butt specifications, see Table 5-1. 

20200729230407 38340 - A Comprehensive Guide to Nickel-based Super Alloy: Hastelloy X (UNS NO6002/W.Nr 2.4665) 20200729230435 47716 - A Comprehensive Guide to Nickel-based Super Alloy: Hastelloy X (UNS NO6002/W.Nr 2.4665)
Fig.5-1 High temperature tensile plasticity diagram of alloy Fig.5-2 Recrystallization curve of upsetting sample

Table 5-1

Metal material to be welded HastelloyX+HastelloyX
Thickness/mm 1.0 + 1.0
State before welding Supply state or solid solution state
Welding wire Grade HHastelloyX  HGH3113
Diameter/mm 1.2-1.6
Joint  form Docking
Welding current/A 40-60
Argon flow/(L/min) 10-13
Tungsten electrode diameter/mm 1.6-2.0
Power supply and polarity DC  Positive polarity

(2) For HastelloyX automatic tungsten pulse argon arc welding butt specification, see Table 5-2. 
Table 5-2

Thickness/mm 1.0  1.2  1.5
State before welding Solid solution
Welding wire Grade   HGH-1  HGH-1
Diameter/mm   1.0  1
Arc voltage/V 8.5  8.5  9
Pulse current/A 60  65  100
Arc current/A 20  22  28
Pulse amplitude ratio 3  3  3.5
Pulse width ratio 2  2  2
Pulse frequency 3  3  3
Welding speed/(m/min) 0.25  0.2  0.23
Wire feeding speed/(m/min)   0.20  0.25

(3) For HastelloyX seam welding specifications, see Table 5-3. 
Table 5-3

Metal material to be welded Thickness/mm State before welding Roller width/mm Welding time/s Rest time/s Welding speed/(m/min) Electrode pressure/kN
on under
HastelloyX+HastelloyX 1.0 + 1.0 Solid solution or supply state 5.5 7 0.14-0.18 0.14-0.22 0.34-0.40 0.25
1.5 + 1.5 5.5 7 0.16-0.20 0.14-0.22 0.22-0.34 0.25

(4) For HastelloyX spot welding specifications, see Table 5-4. 
Table 5-4

Metal material to be welded Thickness/mm State before welding Electrode diameter/mm Welding time/s Electrode pressure/kN Single point shear strength/MPa Tensile strength/MPa
on under
HastelloyX+HastelloyX 1.0 + 1.0 Solid solution or supply state 6 7 0.16-0.24 0.1-0.2 ≥9.35 ≥6.36
1.5 + 1.5 6 7 0.20-0.36 0.2-0.3 ≥12.30 ≥10.60

(5) The mechanical properties of HastelloyX welded joints are shown in Table 5-5. 
Table 5-5

Welding method

Thickness

/mm

State before welding Post-weld treatment

Welding

 wire grade

θ/℃

Joint

 strength

Lasting performance
σb/MPa Strength coefficient/% σ/MPa t/h
Argon arc welding 1.5 Supply status Untreated HHastelloy X 20  800  100     
650  586  100  294  217.6 
815 337 100 110 46.4
Pulse argon arc welding 1 Supply status Untreated 20  842  100     
650 531 90
1.5 Supply status Untreated HSG-1 20  826  100     
650 581 98 294 296.5
Seam welding 1.5 Supply status Untreated 20  763  96     
650  514  91  294  214.2 
815 325 100 110 48.6

3. Heat treatment process of Hastelloy X parts:

  • Solid solution treatment of plate parts: 1150℃±10℃, 2-15min, rapid air cooling.
  • Welding parts or flame tube treatment: 980℃±10℃, 60min, air cooling.
  • Stress relief treatment after machining: 870℃±10℃, 30-60min, air cooling.
  • Stable dimension treatment of parts: 760℃±10℃, 2h, air cooling.

Heat treatment system of hastelloy X (N06002)

Plates and tubes: 1130-1170℃, fast air cooling or water cooling; bar and ring test samples: 1175℃±15℃, air cooling or faster cooling; strip : 1065-1105℃, rapid cooling.
Specifications and supply status of hastelloy X (N06002): supply δ0.5-4.0mm plate, δ0.05-0.8mm strip, outer diameter 4-20mm, wall thickness 1.0-2.0mm pipe , Welding wire with a diameter of 0.2-10.0mm, rods with a diameter of ≤300mm, ring parts with various diameters and wall thicknesses, and precision castings with different shapes and sizes. Plates, strips and pipes are supplied after solution treatment and pickling. Strips can also be supplied in cold rolled state; welding wire is delivered in hard state, semi-hard state, solid solution plus pickling, bright solution treatment state , Can also be delivered straight; bars and ring parts are delivered without heat treatment. Precision castings are supplied in the as-cast state.

Smelting and casting process of hastelloy X (N06002)

Adopts electric arc furnace plus electroslag or non-vacuum induction furnace plus electroslag remelting process. The production of castings uses induction furnace to remelt the master alloy and then pouring it into a heated mold shell. The pouring speed is better. 

Application profile and special requirements of hastelloy X (N06002): This alloy has been widely used in foreign aero-engines and civil industries. China is mainly used to manufacture combustion chamber parts and other hot end parts and honeycomb structures. . The alloy has a certain age hardening phenomenon after long-term use at high temperature.

  • Gas turbines
  • Petrochemical industry
  • Industrial furnaces
  • Heat treating equipment
  • Nuclear engineering
  • Jet engine combustion chambers
  • Aircraft cabin heaters
  • Turbine exhaust components

hastelloy x astm b572 uns n06002 round bars - A Comprehensive Guide to Nickel-based Super Alloy: Hastelloy X (UNS NO6002/W.Nr 2.4665)

Hastelloy X round bars, ASTM B572 Gr. N06002, O.D=219 mm, Length=1025 mm.

Hastelloy X round bars manufactured to ASTM B572 Gr. N06002. Density: 0.297 lb/in3 [8.23 g/cm3]; Condition: hot rolled & solution annealed.

Alloy X is one of the most widely used nickel base superalloys for gas turbine engine combustion zone components such as transition ducts, combustor cans, spray bars and flame holders as well as in afterburners, tailpipes and cabin heaters. It is recommended for use in industrial furnace applications because it has unusual resistance to oxidizing, reducing and neutral atmospheres. Hastelloy X is also used in the chemical process industry for retorts, muffles, catalysts support grids, furnace baffles, tubing for pyrolysis operations and flash drier components.

PREV
NEXT

RELATED POSTS

Leave a Reply

*

*

Inquery now

SUBSCRIBE TO OUR NEWSLETTER

FOLLOW US

WhatsApp Skype

Telephone:
8618267732328
Wechat: 8618267732328
Wechat
Whatsapp

  • Email me
    Mail to us
    Skype