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Nickel Alloy Hastelloy G-2-AW (As-welded deposit)

Heat-treated state

UNS N06975

Use to evaluate weld joint properties; as-welded strength approaches the annealed base metal, but weld dendritic segregation lowers the corrosion margin, so solution treat after welding for severe service.

High cost $$$$

Values for the AW condition

Other Hastelloy G-2 tempers and conditions

Hastelloy G-2 is listed in 5 conditions; see the grade overview at Hastelloy G-2.

Compare all 5 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Hot Finished and Annealed
Pick hot finished and annealed heavy plate, forgings and large-diameter bar for pressure-vessel heads and flanges; coarser grain lowers yield to 280 MPa but keeps 50% elongation.28063550183 HB1.4 % IACS
SADefault
Solution Annealed
Choose mill solution annealed and water quenched sheet, strip, tube or bar for the best corrosion resistance and toughness (295 MPa yield, 48% elongation); the default for chemical equipment.29565548190 HB—
AWThis page
As-welded deposit
Use to evaluate weld joint properties; as-welded strength approaches the annealed base metal, but weld dendritic segregation lowers the corrosion margin, so solution treat after welding for severe service.34064035200 HB1.4 % IACS
Cold drawn
Choose for fasteners, valve stems and pump shafts needing 550 MPa yield with tight dimensional accuracy; control the cold-drawing residual stress with a stress-relief treatment.5507902822 HRC1.4 % IACS
Cold Worked / Hard strip and tube
Pick for spring elements and thin-wall high-pressure tubing needing 720 MPa yield; ductility falls to 12% and intergranular corrosion margin drops, so solution treat after forming.7209301228 HRC1.4 % IACS

What is Hastelloy G-2-AW?

Hastelloy G-2-AW is Hastelloy G-2 heat treated to AW — use to evaluate weld joint properties; as-welded strength approaches the annealed base metal, but weld dendritic segregation lowers the corrosion margin, so solution treat after welding for severe service. Hastelloy G-2-AW has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 63% of nickel alloy grades. Elongation at break is 35% and the elastic modulus is 199 GPa (28.9 Msi). Hastelloy G-2-AW has a density of 8.14 g/cm³ (0.294 lb/in³), lighter than 74% of nickel alloy grades. It melts at 1,330°C (2,426 °F). SA is the default condition FabDigit quotes; AW is available on request or by drawing note.

Limitations

  • Limited service temperature — 540°C (1,004 °F), worse than 75% of nickel alloy grades

Hastelloy G-2-AW properties

Typical room-temperature values for Hastelloy G-2-AW; 21 are specific to this condition. Other listed values are Hastelloy G-2 reference data and may not represent this condition. Bars are the position among nickel alloy grades.

Physical3

Hastelloy G-2-AW has a density of 8.14 g/cm³ (0.294 lb/in³), lighter than 74% of nickel alloy grades. It melts at 1,330°C (2,426 °F).

Density8.14 g/cm³0.29 lb/in³
Melting Point (Solidus)1,330°C2,426 °F
Liquidus Temperature1,390°C2,534 °F

Mechanical13

Hastelloy G-2-AW has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 63% of nickel alloy grades. Elongation at break is 35% and the elastic modulus is 199 GPa (28.9 Msi).

Elastic (Young's) Modulus199 GPa28.9 Msi
Shear Modulus77 GPa11.2 Msi
Bulk Modulus165 GPa23.9 Msi
Poisson's Ratio0.3
Tensile Strength (Ultimate)640 MPa92.8 ksi
Yield Strength (0.2% offset)340 MPa49.3 ksi
Elongation at Break35%
Reduction in Area35%
Shear Strength430 MPa62.4 ksi
Fatigue Strength (Endurance Limit)230 MPa33.4 ksi
Charpy V-Notch Impact (RT)110 J81.1 ft·lbf
Hardness, Brinell200 HB
Hardness, Rockwell B92 HRB

Thermal6

Hastelloy G-2-AW is rated for continuous service to 540°C (1,004 °F). It conducts heat at 10.5 W/m·K (6.07 BTU/hr·ft·°F), worse than 73% of nickel alloy grades. Thermal expansion is 13.6 µm/m·K (7.56 µin/in·°F).

Thermal Conductivity10.5 W/m·K6.1 BTU/hr·ft·°F
Specific Heat Capacity440 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)13.6 µm/m·K7.6 µin/in·°F
Latent Heat of Fusion290 J/g125 BTU/lb
Max Service Temperature (continuous)540°C1,004 °F
Min Service Temperature-196°C-321 °F

Electrical3

Hastelloy G-2-AW conducts electricity at 1.4 % IACS, worse than 65% of nickel alloy grades.

Electrical Conductivity1.4 % IACS
Electrical Resistivity1.23×10⁻⁶ Ω·m48.4 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is very good (76/100), worse than 59% of nickel alloy grades.

Galvanic Potential (seawater, vs SCE)-0.15 V
Corrosion ResistanceVery good76/100
Chemical Resistance Summary—

Sustainability4

Producing a kilogram of Hastelloy G-2-AW takes about 150 MJ of energy and emits 12 kg of CO₂ — less than 68% of nickel alloy grades. Typical recycled content is 35%.

Embodied Energy (primary production)150 MJ/kg64,488 BTU/lb
Embodied Carbon (primary production)12 kg CO₂/kg
Embodied Water350 L/kg41.9 gal/lb
Typical Recycled Content35%

Manufacturability8

Hastelloy G-2-AW's machinability is poor (18/100, worse than 61% of nickel alloy grades); weldability very good (70/100); formability fair (40/100).

MachinabilityPoor18/100
Machinability Rating (AISI 1212 = 100 %)11%
WeldabilityVery good70/100
Formability (cold)Fair40/100
CastabilityFair35/100
Brazeability / SolderabilityGood55/100
PolishabilityVery good75/100
Anodizing Response—

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Hastelloy G-2-AW

Is Hastelloy G-2 easy to machine?

Handle as a nickel corrosion alloy: low speed with heavy feed, rigid clamping, sharp positive-rake tooling (K/M-grade carbide) and generous emulsion coolant to prevent rubbing that builds a work-hardened layer.

Can Hastelloy G-2 be welded?

Mainly GTAW and GMAW using matching filler or ERNiCrMo-1 (Alloy G-3). Keep heat input low and interpass temperature below 100 °C, no preheat required; a post-weld solution treatment can be used for severe corrosion service.

Can Hastelloy G-2 be formed, bent or molded?

Ductile in the annealed condition for cold pressing, plate rolling and tube expanding, but the work-hardening rate is high, so deep forming needs intermediate anneals at about 1120 °C followed by water quench. Hot work at roughly 900–1180 °C.

What surface finishes work on Hastelloy G-2?

Not suitable for anodizing. Remove scale by nitric-hydrofluoric pickling and then passivate, or mechanically polish / electropolish to a low roughness to improve pitting resistance.

Hastelloy G-2 chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
Ni47 – 5249.5
Cr23 – 2624.5
Mo5 – 76
Cuimproves corrosion resistance in reducing acids0.7 – 1.20.9
Tistabilizer, suppresses intergranular corrosion0.7 – 1.51
C≤ 0.030.02
Mn≤ 10.5
Si≤ 10.4
P≤ 0.03—
S≤ 0.03—
Febalance, typically 15–20%balance—

Hastelloy G-2-AW — frequently asked

What is Hastelloy G-2-AW used for?

Hastelloy G-2-AW is typically used for sulfuric acid alkylation units, mixed acid service, chemical process vessels and acid coolers. In short: mixed nitric-sulfuric acid grade; cu-bearing Ni-Cr-Mo alloy; 540 °C service limit.

What is the yield strength of Hastelloy G-2-AW?

Hastelloy G-2-AW has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 63% of nickel alloy grades. Strength varies by condition: see the 5 listed tempers.

Is Hastelloy G-2-AW easy to machine?

Not especially — machinability is rated poor (18/100, worse than 61% of nickel alloy grades). Handle as a nickel corrosion alloy: low speed with heavy feed, rigid clamping, sharp positive-rake tooling (K/M-grade carbide) and generous emulsion coolant to prevent rubbing that builds a work-hardened layer.

Can Hastelloy G-2-AW be welded?

Yes — weldability is rated very good (70/100). Mainly GTAW and GMAW using matching filler or ERNiCrMo-1 (Alloy G-3). Keep heat input low and interpass temperature below 100 °C, no preheat required; a post-weld solution treatment can be used for severe corrosion service.

What surface finishes work on Hastelloy G-2-AW?

Not suitable for anodizing. Remove scale by nitric-hydrofluoric pickling and then passivate, or mechanically polish / electropolish to a low roughness to improve pitting resistance.

Can Hastelloy G-2-AW be formed, bent or molded?

Ductile in the annealed condition for cold pressing, plate rolling and tube expanding, but the work-hardening rate is high, so deep forming needs intermediate anneals at about 1120 °C followed by water quench. Hot work at roughly 900–1180 °C.

What is the maximum service temperature of Hastelloy G-2-AW?

Hastelloy G-2-AW is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between Hastelloy G-2-SA and Hastelloy G-2 CW-H?

SA is the default condition — choose mill solution annealed and water quenched sheet, strip, tube or bar for the best corrosion resistance and toughness (295 MPa yield, 48% elongation); the default for chemical equipment. CW-H: pick for spring elements and thin-wall high-pressure tubing needing 720 MPa yield; ductility falls to 12% and intergranular corrosion margin drops, so solution treat after forming. Yield strength is 295 MPa in SA versus 720 MPa in CW-H.

Sources

  1. ASTM B582 — Ni-Cr-Fe-Mo-Cu Alloy Plate, Sheet and Strip (N06975) — ASTM International (2019)
  2. ASTM B581 — Ni-Cr-Fe-Mo-Cu Alloy Rod and Bar (N06975) — ASTM International (2019)
  3. ASTM B622 / B626 — Seamless and Welded Ni-Alloy Pipe and Tube — ASTM International (2022)
  4. HASTELLOY G-series Alloys (G, G-2, G-3, G-30) technical data — Haynes International (2020)
  5. ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
  6. ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.