Stainless Steel Incoloy 800 · grade
Stainless Steel Incoloy 800-HF
Properties of the HF condition, compared with the other Incoloy 800 tempers.
Pick for heavy bar, forgings and thick plate where hot-worked strength is adequate and a machining allowance covers the scaled surface.
What is Incoloy 800-HF?
Incoloy 800-HF is Incoloy 800 in the HF grade — pick for heavy bar, forgings and thick plate where hot-worked strength is adequate and a machining allowance covers the scaled surface. Incoloy 800-HF has a yield strength of 310 MPa (45 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 63% of stainless steel grades. Elongation at break is 38% and the elastic modulus is 196 GPa (28.4 Msi). Incoloy 800-HF has a density of 7.94 g/cm³ (0.287 lb/in³), heavier than 78% of stainless steel grades. It melts at 1,357°C (2,475 °F). ANN is the default condition FabDigit quotes; HF is available on request or by drawing note.
Advantages
- High service temperature — 815°C (1,499 °F), better than 77% of stainless steel grades
Limitations
- Poor heat conductor — 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 96% of stainless steel grades
- High embodied carbon — 6.5 kg CO₂/kg, worse than 92% of stainless steel grades
- Low electrical conductivity — 1.8 % IACS, worse than 88% of stainless steel grades
Incoloy 800-HF properties
Typical room-temperature values for Incoloy 800-HF — 15 properties are specific to this condition; the rest are grade-level values shared by every Incoloy 800 temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
Incoloy 800-HF has a density of 7.94 g/cm³ (0.287 lb/in³), heavier than 78% of stainless steel grades. It melts at 1,357°C (2,475 °F).
Mechanical15
Incoloy 800-HF has a yield strength of 310 MPa (45 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 63% of stainless steel grades. Elongation at break is 38% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal5
Incoloy 800-HF is rated for continuous service to 815°C (1,499 °F). It conducts heat at 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 96% of stainless steel grades. Thermal expansion is 14.4 µm/m·K (8 µin/in·°F).
Electrical3
Incoloy 800-HF conducts electricity at 1.8 % IACS, worse than 88% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 63% of stainless steel grades.
Sustainability4
Producing a kilogram of Incoloy 800-HF takes about 95 MJ of energy and emits 6.5 kg of CO₂ — more than 96% of stainless steel grades. Typical recycled content is 45%.
Manufacturability8
Incoloy 800-HF's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability very good (78/100); formability good (65/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Incoloy 800 tempers and conditions
Incoloy 800 is also supplied in 6 other conditions. The full side-by-side table is on the Incoloy 800 overview.
- ANNDefaultDefault stocked condition for plate, sheet, tube and bar — maximum ductility, uniform grain structure and best corrosion/oxidation behaviour.260 MPa yield · 140 HB
- FHHighest room-temperature strength and hardness for spring strip, wire and cold-drawn tube; very limited formability and cold work is lost by recovery above ~500 °C.830 MPa yield · 31 HRC
- 1/2HChoose when roughly double the annealed yield strength is needed at room temperature with some residual bend ductility (springs, fasteners, stiff tubing).620 MPa yield · 23 HRC
- CDCold-drawn bar or tube with a low-temperature stress relief — good dimensional accuracy and surface finish with moderately raised yield.520 MPa yield · 215 HB
- 1/4HLight cold work for extra stiffness/yield in strip and tube while keeping useful bendability.470 MPa yield · 200 HB
- HFPick for heavy bar, forgings and thick plate where hot-worked strength is adequate and a machining allowance covers the scaled surface.310 MPa yield · 160 HB
Working with Incoloy 800-HF
Is Incoloy 800 easy to machine?
Machine like a tough austenitic: rigid setup, positive-rake sharp carbide, 15–35 m/min surface speed, heavy feed to cut under the work-hardened skin, and flood coolant — avoid dwelling.
Can Incoloy 800 be welded?
Readily welded by GTAW/GMAW/SMAW with ERNiCr-3 (Inconel 82) or ENiCrFe-3; no preheat, low heat input, clean sulphur-free surfaces, no post-weld heat treatment normally required.
Can Incoloy 800 be formed, bent or molded?
Excellent cold formability in the annealed condition but work-hardens faster than 304, so allow extra power and interstage anneals at 980–1050 °C; hot work between 870 and 1200 °C.
What surface finishes work on Incoloy 800?
Not anodizable — pickle in HNO3/HF or grit blast plus passivate to restore the chromia film; polishes well and can be electropolished for high-purity service.
Incoloy 800 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 |
|---|---|---|
| Ni | 30 – 35 | 32.5 |
| Cr | 19 – 23 | 21 |
| C0.05–0.10 for 800H/800HT | ≤ 0.1 | 0.05 |
| Mn | ≤ 1.5 | 0.8 |
| Si | ≤ 1 | 0.5 |
| S | ≤ 0.02 | 0.01 |
| Cu | ≤ 0.75 | 0.3 |
| Al | 0.15 – 0.6 | 0.35 |
| TiAl+Ti also specified 0.30–1.20 in some specs | 0.15 – 0.6 | 0.35 |
| Febalance, 39.5 % minimum per ASTM | ≥ 39.5 (balance) | — |
Incoloy 800-HF — frequently asked
What is Incoloy 800-HF used for?
Incoloy 800-HF is typically used for heat exchanger tubing, furnace muffles and retorts, petrochemical reformer tubing and steam generator components. In short: baseline 800-series alloy; oxidation and carburization resistant; cheaper than nickel-base alternatives.
What is the yield strength of Incoloy 800-HF?
Incoloy 800-HF has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 63% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is Incoloy 800-HF easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Machine like a tough austenitic: rigid setup, positive-rake sharp carbide, 15–35 m/min surface speed, heavy feed to cut under the work-hardened skin, and flood coolant — avoid dwelling.
Can Incoloy 800-HF be welded?
Yes — weldability is rated very good (78/100). Readily welded by GTAW/GMAW/SMAW with ERNiCr-3 (Inconel 82) or ENiCrFe-3; no preheat, low heat input, clean sulphur-free surfaces, no post-weld heat treatment normally required.
What surface finishes work on Incoloy 800-HF?
Not anodizable — pickle in HNO3/HF or grit blast plus passivate to restore the chromia film; polishes well and can be electropolished for high-purity service.
Can Incoloy 800-HF be formed, bent or molded?
Excellent cold formability in the annealed condition but work-hardens faster than 304, so allow extra power and interstage anneals at 980–1050 °C; hot work between 870 and 1200 °C.
What is the maximum service temperature of Incoloy 800-HF?
Incoloy 800-HF is rated for continuous use to about 815°C (1,499 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Incoloy 800-ANN and Incoloy 800-FH?
ANN is the default condition — default stocked condition for plate, sheet, tube and bar — maximum ductility, uniform grain structure and best corrosion/oxidation behaviour. FH: highest room-temperature strength and hardness for spring strip, wire and cold-drawn tube; very limited formability and cold work is lost by recovery above ~500 °C. Yield strength is 260 MPa in ANN versus 830 MPa in FH.
Sources
- ASTM B409 / B408 / B407 (N08800 plate, bar, tube) — ASTM International (2022)
- INCOLOY alloy 800 technical bulletin — Special Metals Corporation (2004)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- EN 10095 / VdTÜV 434 — X10NiCrAlTi32-21 (1.4876) — CEN (2018)
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.