Nickel-based super alloy: Hastelloy X (UNS N06002)

What is Hastelloy X?

Hastelloy X (UNS N06002/W.Nr. 2.4665/Alloy X) 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. This Alloy X exhibits good ductility after prolonged exposure at temperatures of 650°C[1200°F], 760[1400°F] and 870°C[1600°F] for a period of 16000 hours. Hastelloy X are widely used in gas turbines, petrochemical and nuclear industries, furnaces, pressure equipment, and aircraft components.

hastelloy c22 flanges - Nickel-based super alloy: Hastelloy X (UNS N06002)

ASME B16.47 Series A Hastelloy X weld neck flanges

Characteristics of Hastelloy X (UNS N06002)

  • Excellent oxidation resistance at high temperature(>1200℃)).
  • Good high-temperature strength.
  • Good formability and weldability.
  • Good resistance to stress corrosion cracking.

20200902224436 49046 - Nickel-based super alloy: Hastelloy X (UNS N06002)

Hastelloy X Forged Elbow 1″ 3000#

Types of Hastelloy

  • Hastelloy B-3 nickel molybdenum alloy has excellent corrosion resistance in reducing environment
  • The upgraded version of Hastelloy B-3: B-3 has excellent corrosion resistance to hydrochloric acid at any temperature and concentration
  • Hastelloy C-4: good thermal stability, good toughness and corrosion resistance at 650-1040 ℃
  • Hastelloy C-22: has better uniform corrosion resistance than C-4 and C-276 in oxidizing medium and excellent local corrosion resistance
  • Hastelloy C-276: good resistance to oxidizing and moderate reducing corrosion, excellent resistance to stress corrosion
  • Hastelloy C-2000: the most comprehensive corrosion resistant alloy with excellent uniform corrosion resistance in oxidation and reduction environments
  • Hastelloy G-35: the upgraded product of G-30 has better corrosion resistance and thermal stability, and has excellent performance in phosphoric acid and other strong oxidizing mixed acid media with high chromium content
  • Hastelloy X: combined with the characteristics of high strength, oxidation resistance and easy processing, each of the above grades has its own specific chemical composition, mechanical properties and strong points, so we can’t generalize the characteristics of Hastelloy.

Hastelloy alloy is mainly divided into three series B, C and G. it is mainly used in iron-based Cr Ni or Cr Ni Mo stainless steel, non-metallic materials and other occasions with strong corrosive medium.
In order to improve the corrosion resistance and cold and hot working properties of Hastelloy, three major improvements have been made to Hastelloy:

  • Series B: B → B-3 (00ni70mo28) → B-3
  • Series C: C → C-276 (00cr16mo16w4) → C-4 (00cr16mo16) → X (00cr22mo13w3) → C-2000 (00cr20mo16)
  • G Series: G → G-3 (00cr22ni48mo7cu) → G-30 (00cr30ni48mo7cu)
  • The most widely used materials are N06002 (B-3), N10276 (C-276), N06002 (X), N06455 (C-4) and N06985 (G-3)

Chemical Composition of Hastelloy X (UNS N06002)

C Cr Ni Fe Mo W Al B Co Si Mn P S
0.05~0.15 20.5~23.5 balance 17.0~20.0 8.0~10.0 0.2~1.0 ≤0.1 ≤0.005 0.5~2.5 ≤1.0 ≤1.0 ≤0.015 ≤0.01

hastelloy x astm b572 uns n06002 round bars - Nickel-based super alloy: Hastelloy X (UNS N06002)

ASTM B572 Hastelloy X round bars

Equivalent Grades of Hastelloy X (UNS N06002)

Hastelloy X GH3536 Hastelloy X N06002 NiCr22Fe18Mo 2.4665 HR 6 NC22FeD
Inconel HX Inconel HX HR 204
Nicrofer 4722 Co
Nimonic PE13

Physical Properties of Hastelloy X (UNS N06002)

Density (g/cm3) Melting temperature (℃) Elastic modulus(GPa) Hardness(HBS) Thermal conductivity Specific Heat Electrical Resistivity
λ( W/(m•K) J/kg.k µΩ·m
8.3 1260~1355 142-199 ≤241 13.38 486 1180

Mechanical Properties of Hastelloy X (UNS N06002)

Temperature Tensile strength/MPa  Yield strength Elongation
MPa %
20 760 378 44
540 614 245 49
650 572 244 54
760 462 237 53
Varieties Room temperature tensile properties Endurance at 815 ℃ Other performance
σP0.2/MPa σb/MPa δ5/% σ/MPa t/h δ5/%
Not less than
Cold rolled sheet 310 725 35 110 24 8 Bending 180 degrees
Cold rolled strip 310 760 30 Bending 180 degrees
Cold drawn pipe 310 690 25 Hydraulic, flaring
Bar 275 690 30 105 24 10 HBS≤241
Ring piece 275 690 30 105 24 10 HBS≤241
Investment casting 200 380 10 HBS≤96
  • ① Room temperature tensile strength σ of strip with δ < 0.25mm b ≥725MPa,δ five ≥25%。
  • ② As cast at 815 ℃ b ≥240MPa,δ five ≥12%。 After cold treatment, the temperature was less than or equal to 800 ℃ after air cooling.

Product Forms and Standards of Hastelloy X

Product Form Standard
Rod 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
Welding 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 melting temperature range of Hastelloy x (n06002) alloy is as follows:

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

The thermal conductivity of Hastelloy x (n06002) alloy is as follows:

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

The specific heat capacity of Hastelloy x (n06002) alloy is as follows:

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

The linear expansion coefficient of Hastelloy x (n06002) alloy is as follows:

θ/℃ 24 100 300 400 500 600 700 800 900
Q/(10-6m2/S)) 2.78 3.06 3.68 3.64 4.36 4.32 4.38 4.91 5.23

The thermal diffusivity of Hastelloy x (n06002) alloy casting is as follows:

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

Oxidation resistance: the oxidation rate of the alloy after 100 h in air medium is shown.

θ/℃ 700 800 900 1000 1100
Oxidation rate/(g/(m2·h)) 0.0023 0.060 0.117 0.200 0.611

Forming processing of Hastelloy X (UNS N06002)

Cold working and forming of the various product forms can be done with standard tooling and processing.

Machinability of Hastelloy X (UNS N06002)

The alloy is machinable by conventional methods and is similar to machining of the austenitic (300 series) stainless steels.

Forging of Hastelloy X (UNS N06002)

Hot forging can be accomplished by conventional practice.

Cold Working of Hastelloy X (UNS N06002)

Readily cold worked in a manner similar to that for austenitic (300 series) stainless steels except that this alloy is somewhat “stiffer” and may require more forming pressure. After severe cold working the product can be solution annealed as indicated in “Heat Treating”.

Aging of Hastelloy X (UNS N06002)

The alloy can be aged, after solution heat treatment, at temperatures of 1200 to 1600 F. Aging will result in a slight increase in strength and hardness with the effect being related to hours of exposure at the aging temperature – the longer the time the greater the effect.

Welding of Hastelloy X (UNS N06002)

Welding by conventional processes such as resistance welding, shielded metal arc, and MIG or TIG can readily be done with this alloy. Matching filler metal should be used. Preheating and/or post heating are not required.

Heat treatment of Hastelloy X (UNS N06002)

The alloy usually is supplied in the solution annealed condition. This is accomplished at 2150 F followed by a rapid cooling.

  • Plate and tube: 1130 ~ 1170 ℃, rapid air cooling or water cooling;
  • Bar and ring inspection sample: 1175 ℃± 15 ℃, air cooling or faster cooling;
  • Strip: 1065 ~ 1105 ℃, rapid cooling.

Application areas of nickel-based alloy Hastelloy X (UNS N06002):

20200902225659 70005 - Nickel-based super alloy: Hastelloy X (UNS N06002)

An Alloy X 90DEG Elbow 6″ SCH80S extruded from the UNS N06002 seamless pipe.

Due to its corrosion resistance to all kinds of atmosphere at high temperatures,and excellent high-temperature strength, Hastelloy X has been widely used in various high temperature environment. Some of the more common uses of Hastelloy X include:

  • Wire wound resistors.
  • Bimetal contacts.
  • Electric and electronic applications.
  • Marine engineering.
  • Chemical and hydrocarbon processing equipment.
  • Gasoline and freshwater tanks.
  • Crude petroleum stills.
  • De-aerating heaters.
  • Boiler feed water heaters and other heat exchangers.
  • Pumps, shafts and fasteners.
  • Industrial heat exchangers.
  • Chlorinated solvents.
  • Crude oil distillation towers.
  • Meter and valve parts.
  • Screw machine products.
  • Oil refinery piping.
  • Heat exchangers.
  • Nuclear fuel production.
  • Generator tubing.
  • High temperature heating coils.
  • Crude oil transfer piping.
  • Propeller and pump shafts.
  • Piping system.
  • Heat exchange tubes.
  • Pipe fittings.
  • Flanges.
  • Valves.

Variety specifications and supply status of Nickel-based super alloy: Hastelloy X (UNS N06002):

Variety classification:

Yaang Pipe Industry can produce various specifications of Hastelloy X seamless pipeHastelloy X steel plateHastelloy X round bar, Hastelloy X forgings, Hastelloy X flangeHastelloy X pipe fittings, Hastelloy X welded pipe, Hastelloy X steel strip, Hastelloy X wire and supporting welding materials. 

Delivery status:

  • Seamless pipe: solid solution + acid white, length can be set;
  • Plate: solid solution, pickling, trimming;
  • Welded pipe: solid solution acid white + RT% flaw detection;
  • Forging: annealing + car polish; Bars are forged and rolled, surface polished or car polished;
  • Strips are delivered after cold rolling, solid solution soft state, and deoxidized;
  • Wire rods are finely ground in solid solution pickled disk or straight strips, solid solution straight strips Delivery in light state.

Source: China Hastelloy X Flanges Manufcturer – Yaang Pipe Industry (

(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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Nickel-based super alloy: Hastelloy X (UNS N06002)
Hastelloy X (UNS N06002/W.Nr. 2.4665/Alloy X) is a nickel-chromium-iron-molybdenum alloy that possesses an exceptional combination of oxidation resistance, fabricability, and high-temperature strength.
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