Nickel Alloy Hastelloy G-HF (Hot Worked / Hot Finished)
Grade
UNS N06007, N06920 · EN 2.4618
Heavy bar, ring and forging sections where hot working is followed by solution anneal; slightly lower strength scatter than cold work.
Values for the HF condition
Other Hastelloy G tempers and conditions
Hastelloy G is listed in 5 conditions; see the grade overview at Hastelloy G.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HFThis page Hot Worked / Hot Finished | Heavy bar, ring and forging sections where hot working is followed by solution anneal; slightly lower strength scatter than cold work. | 300 | 670 | 50 | 175 HB | 1.5 % IACS |
ANNDefault Annealed | Standard stocked condition for plate, sheet, tube and forgings in acid service — best corrosion resistance and ductility. | 310 | 690 | 55 | 180 HB | — |
As-welded deposit | Weld metal / as-welded joint properties for fabricated vessels; solution anneal after welding where sensitization is a concern. | 420 | 680 | 35 | 13 HRC | 1.5 % IACS |
Cold drawn | Choose for straight, close-tolerance bar/tube and higher yield strength fasteners and shafts in acid plant hardware. | 550 | 800 | 30 | 22 HRC | 1.5 % IACS |
Cold worked | Springs, clips and thin strip needing maximum strength; corrosion performance and ductility both reduced versus annealed. | 750 | 950 | 15 | 30 HRC | 1.5 % IACS |
What is Hastelloy G-HF?
Hastelloy G-HF is Hastelloy G in the HF grade — heavy bar, ring and forging sections where hot working is followed by solution anneal; slightly lower strength scatter than cold work. Hastelloy G-HF has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 670 MPa (97.2 ksi) — weaker than 78% of nickel alloy grades. Elongation at break is 50% and the elastic modulus is 198 GPa (28.7 Msi). Hastelloy G-HF has a density of 8.31 g/cm³ (0.3 lb/in³), heavier than 51% of nickel alloy grades. It melts at 1,260°C (2,300 °F). ANN is the default condition FabDigit quotes; HF is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 50%, better than 88% of nickel alloy grades
- Low embodied carbon — 11 kg CO₂/kg, better than 85% of nickel alloy grades
Limitations
- Low strength — 300 MPa (43.5 ksi), worse than 78% of nickel alloy grades
Hastelloy G-HF properties
Typical room-temperature values for Hastelloy G-HF; 21 are specific to this condition. Other listed values are Hastelloy G reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
Hastelloy G-HF has a density of 8.31 g/cm³ (0.3 lb/in³), heavier than 51% of nickel alloy grades. It melts at 1,260°C (2,300 °F).
Mechanical13
Hastelloy G-HF has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 670 MPa (97.2 ksi) — weaker than 78% of nickel alloy grades. Elongation at break is 50% and the elastic modulus is 198 GPa (28.7 Msi).
Thermal6
Hastelloy G-HF is rated for continuous service to 550°C (1,022 °F). It conducts heat at 10.1 W/m·K (5.84 BTU/hr·ft·°F), worse than 84% of nickel alloy grades. Thermal expansion is 13.9 µm/m·K (7.72 µin/in·°F).
Electrical3
Hastelloy G-HF conducts electricity at 1.5 % IACS, better than 59% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 74% of nickel alloy grades.
Sustainability4
Producing a kilogram of Hastelloy G-HF takes about 145 MJ of energy and emits 11 kg of CO₂ — less than 77% of nickel alloy grades. Typical recycled content is 40%.
Manufacturability7
Hastelloy G-HF's machinability is poor (25/100, better than 76% of nickel alloy grades); weldability very good (70/100); formability good (65/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Hastelloy G-HF
Is Hastelloy G easy to machine?
Machine like a gummy austenitic Ni alloy: rigid setups, positive-rake carbide, low speed/heavy feed, flood coolant and no dwelling to avoid work-hardened glaze.
Can Hastelloy G be welded?
GTAW/GMAW/SMAW with matching ERNiCrMo-1 or G-3 filler, stringer beads, low heat input and interpass <100 °C; post-weld solution anneal if the HAZ will see hot acid.
Can Hastelloy G be formed, bent or molded?
Very ductile in the annealed state but work-hardens fast — allow extra press tonnage, generous radii and interstage anneals at ~1100 °C with rapid cooling.
What surface finishes work on Hastelloy G?
Pickle (HNO₃-HF) or bead-blast to remove weld/heat-tint oxide, then passivate; no anodizing — mechanical polish or electropolish for hygienic/acid surfaces.
Hastelloy G 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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | ≤ 0.05 | 0.03 |
| Mn | 1 – 2 | 1.5 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Cr | 21 – 23.5 | 22 |
| Fe | 18 – 21 | 19.5 |
| Mo | 5.5 – 7.5 | 6.5 |
| Cuimproves resistance in sulfuric acid | 1.5 – 2.5 | 2 |
| Nb+Tastabilizer against intergranular attack | 1.75 – 2.5 | 2.1 |
| Co | ≤ 2.5 | — |
| W | ≤ 1 | — |
| Nibalance, approx. 42–46 % | balance | — |
Hastelloy G-HF — frequently asked
What is Hastelloy G-HF used for?
Hastelloy G-HF is typically used for phosphoric acid production, sulfuric acid handling and chemical process piping. In short: original acid-service Hastelloy; superseded by G-3/G-30; good weldability and formability.
What is the yield strength of Hastelloy G-HF?
Hastelloy G-HF has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 670 MPa (97.2 ksi) — weaker than 78% of nickel alloy grades. Strength varies by condition: see the 5 listed tempers.
Is Hastelloy G-HF easy to machine?
Not especially — machinability is rated poor (25/100, better than 76% of nickel alloy grades). Machine like a gummy austenitic Ni alloy: rigid setups, positive-rake carbide, low speed/heavy feed, flood coolant and no dwelling to avoid work-hardened glaze.
Can Hastelloy G-HF be welded?
Yes — weldability is rated very good (70/100). GTAW/GMAW/SMAW with matching ERNiCrMo-1 or G-3 filler, stringer beads, low heat input and interpass <100 °C; post-weld solution anneal if the HAZ will see hot acid.
What surface finishes work on Hastelloy G-HF?
Pickle (HNO₃-HF) or bead-blast to remove weld/heat-tint oxide, then passivate; no anodizing — mechanical polish or electropolish for hygienic/acid surfaces.
Can Hastelloy G-HF be formed, bent or molded?
Very ductile in the annealed state but work-hardens fast — allow extra press tonnage, generous radii and interstage anneals at ~1100 °C with rapid cooling.
What is the maximum service temperature of Hastelloy G-HF?
Hastelloy G-HF is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Hastelloy G-ANN and Hastelloy G-CW?
ANN is the default condition — standard stocked condition for plate, sheet, tube and forgings in acid service — best corrosion resistance and ductility. CW: springs, clips and thin strip needing maximum strength; corrosion performance and ductility both reduced versus annealed. Yield strength is 310 MPa in ANN versus 750 MPa in CW.
Sources
- ASTM B582 — Nickel-Chromium-Iron-Molybdenum-Copper Alloy Plate, Sheet and Strip (N06007) — ASTM International (2019)
- ASTM B581 — Ni-Cr-Fe-Mo-Cu Alloy Rod (N06007) — ASTM International (2019)
- ASTM B622/B619 — Seamless and Welded Nickel Alloy Pipe and Tube — ASTM International (2020)
- Hastelloy alloy G / G-3 technical data — Haynes International (formerly Cabot Corp.) (1990)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys — ASM International (2000)
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.