Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Incoloy 800H — Nickel-Iron-Chromium Alloy for High-Temperature Service
Incoloy 800H (UNS N08810, Werkstoff 1.4876, DIN X10NiCrAlTi32-21) is an austenitic nickel-iron-chromium alloy with 30 to 35 percent nickel, 19 to 23 percent chromium and a balance of iron, controlled to a carbon range of 0.05 to 0.10 percent and an ASTM grain size of 5 or coarser to deliver enhanced creep and stress-rupture strength above 600 deg C (1100 deg F). Incoloy 800HT (UNS N08811) is the higher-temperature variant of the same chemistry with a combined Al plus Ti window of 0.85 to 1.20 percent for service above 700 deg C (1290 deg F). Both grades are specified into ethylene cracker pigtails, hydrocarbon reformer tubes, fired heater radiant sections, steam superheaters, heat exchanger tubes, furnace fixtures and ASME Section VIII pressure vessels where oxidation, carburization and sulfidation resistance must hold to 982 deg C (1800 deg F). TorqBolt supplies Incoloy 800H to ASTM B407 (seamless pipe and tube), ASTM B408 (rod and bar), ASTM B409 (plate, sheet and strip), ASTM B564 (forgings) and ASME SB-series adoptions.
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Incoloy 800H International Designations and Equivalents
| Designation system | Incoloy 800H | Incoloy 800HT |
|---|---|---|
| UNS (Unified Numbering System) | N08810 | N08811 |
| Werkstoff (German register) | 1.4876 | 1.4959 |
| DIN chemical-symbol designation | X10NiCrAlTi32-21 | X8NiCrAlTi32-21 |
| ASTM (primary specification family) | B407 / B408 / B409 / B514 / B515 / B564 | B407 / B408 / B409 / B514 / B515 / B564 |
| ASME (boiler & pressure vessel code) | SB-407 / SB-408 / SB-409 / SB-564 | SB-407 / SB-408 / SB-409 / SB-564 |
| Common trade names | INCOLOY alloy 800H, Alloy 800H, Inco 800H | INCOLOY alloy 800HT, Alloy 800HT |
| Originator / brand | Special Metals (Huntington Alloys) | Special Metals (Huntington Alloys) |
Incoloy 800H Chemical Composition (Ni-Fe-Cr Family)
| Element | 800H (N08810), percent | 800HT (N08811), percent | Role |
|---|---|---|---|
| Nickel (Ni) | 30.0 to 35.0 | 30.0 to 35.0 | Austenite stabilizer; oxidation resistance |
| Chromium (Cr) | 19.0 to 23.0 | 19.0 to 23.0 | Cr2O3 passive film; high-temp oxidation |
| Iron (Fe) | balance (~39.5) | balance (~39.5) | Matrix; cost-base solution-strengthening |
| Carbon (C) | 0.05 to 0.10 | 0.06 to 0.10 | Creep strength via carbide precipitation |
| Aluminium (Al) | 0.15 to 0.60 | 0.25 to 0.60 | Combined Al+Ti for creep + carburization resistance |
| Titanium (Ti) | 0.15 to 0.60 | 0.25 to 0.60 | Combined Al+Ti for stability |
| Al + Ti combined | 0.30 to 1.20 | 0.85 to 1.20 | Defines 800H vs 800HT distinction |
| Manganese (Mn) | 1.5 maximum | 1.5 maximum | Sulfur tie-up; deoxidation residual |
| Silicon (Si) | 1.0 maximum | 1.0 maximum | Deoxidation; mild oxidation aid |
| Copper (Cu) | 0.75 maximum | 0.75 maximum | Tramp limit |
| Sulfur (S) | 0.015 maximum | 0.015 maximum | Tramp limit |
Incoloy 800H Mechanical Properties (Solution Annealed)
| Property | Incoloy 800H | Incoloy 800HT | Test condition |
|---|---|---|---|
| Tensile strength (Rm) | >= 450 MPa (65 ksi) | >= 450 MPa (65 ksi) | RT, solution annealed |
| 0.2 percent proof stress (Rp0.2) | >= 170 MPa (25 ksi) | >= 170 MPa (25 ksi) | RT, solution annealed |
| Elongation A5 | >= 30 percent | >= 30 percent | RT, longitudinal |
| Hardness (HB) | 120 to 184 | 120 to 184 | Brinell, max for ASTM |
| Tensile at 540 deg C (1000 deg F) | >= 415 MPa (60 ksi) | >= 415 MPa (60 ksi) | ASTM high-temp test |
| Tensile at 815 deg C (1500 deg F) | ~ 200 MPa (29 ksi) | ~ 200 MPa (29 ksi) | ASTM high-temp test |
| Creep rupture stress (10,000 hr) at 815 deg C | ~ 35 MPa (5 ksi) | ~ 45 MPa (6.5 ksi) | ASME Section VIII basis |
| ASTM grain size | 5 or coarser | 5 or coarser | Required for creep certification |
| Maximum service temperature | 982 deg C (1800 deg F) | 1093 deg C (2000 deg F) | Oxidation envelope |
Where Incoloy 800H Is Specified (Petrochemical, Refining, Power)
Incoloy 800H is the standard structural material in petrochemical and refining high-temperature service where the operating envelope sits above 600 deg C (1100 deg F) and conventional 300-series stainless steels fall out of useful creep life. The decisive selection drivers are creep-rupture strength to ASME Section VIII design tables, oxidation resistance to 982 deg C (1800 deg F), carburization resistance in hydrocarbon furnace atmospheres, and stable austenitic structure with no sigma-phase embrittlement on long-term exposure.
- Ethylene Cracker Tubes: Incoloy 800H radiant pigtails and convection bundles in steam-cracker furnaces for ethylene and propylene production.
- Reformer Pigtails: Outlet pigtails from primary steam-methane reformer tubes, connecting catalyst tubes to outlet headers.
- Hydrocarbon Cracking Furnaces: Furnace tube hairpins, return bends and crossovers in ethylene, propylene and aromatics units.
- Radiant Tubes: Indirect-fired furnace radiant tubes in heat-treating and carburizing service.
- Furnace Components: Hearth plates, fixtures, retort assemblies and muffle linings for batch and continuous furnaces.
- Steam Superheater Tubes: Final-stage superheaters and reheaters in fossil and waste-heat boilers.
- Heat Exchanger Tubes: Process-side high-temperature exchangers in refinery hydrocracker units and coal gasification.
- Pressure Vessels (ASME Section VIII): Code-qualified vessels for hydrocarbon processing and chemical service above 540 deg C (1000 deg F).
Incoloy 800H Forms Supplied
TorqBolt supplies Incoloy 800H and Incoloy 800HT across the fasteners, forgings, fittings, flanges, machined components, pipe, tube, plate, sheet and bar form-factor range covered by ASTM B-series specifications. Material is supplied solution-annealed in the high-temperature anneal condition required for ASTM grain size 5 or coarser, with EN 10204 type 3.1 mill test certificate by default and type 3.2 with Lloyds Register, DNV, BV, SGS or TUV witness on call-out.
| Form factor | Specification + size range | Page |
|---|---|---|
| Fasteners (Bolts, Nuts, Studs, Washers, Rods) | Full range — see Fasteners hub | Fasteners |
| Forgings (TorqBolt-manufactured) | ASTM B564, up to 1500 kg piece weight | Forgings |
| Flanges (TorqBolt-manufactured) | ASME B16.5, NPS 1/2" to 24", Class 150 to 2500 | Flanges |
| Fittings (Buttweld + Socketweld + Threaded) | ASME B16.9 / B16.11, NPS 1/2" to 24" | Fittings |
| Machined Components (custom) | Per project drawing | Machined Components |
| Seamless pipe | ASTM B407, NPS 1/2" to 12", Sch 10S to XXS | Seamless Pipe |
| Welded pipe | ASTM B514, NPS 1/2" to 24" | Welded Pipe |
| Seamless tube | ASTM B407, OD 6 mm to 150 mm, wall 1 mm to 12 mm | Seamless Tube |
| Centrifugally cast tubes | ASTM A608, primary ethylene-cracker form | Centrifugally Cast Tubes |
| Plate | ASTM B409, thickness 4.75 mm to 100 mm | Plate |
| Sheet | ASTM B409, thickness 0.4 mm to 4.75 mm | Sheet |
| Round bar | ASTM B408, OD 8 mm to 250 mm | Round Bar |
Where Incoloy 800H Sits Against Neighbouring Grades
| Grade | UNS | Service envelope | Why choose / when to step |
|---|---|---|---|
| Incoloy 800 (standard) | N08800 | up to 650 deg C (1200 deg F) | Step up to 800H when sustained service exceeds 650 deg C |
| Incoloy 800H | N08810 | up to 815 deg C (1500 deg F) | Petrochem furnace tubes, ASME VIII vessels, reformer pigtails |
| Incoloy 800HT | N08811 | up to 982 deg C (1800 deg F) | Highest sustained creep strength when Al+Ti window is required |
| Incoloy 825 | N08825 | Corrosion service to 540 deg C | Step laterally for sulfuric / phosphoric acid corrosion (not high-temp creep) |
| Inconel 600 | N06600 | Carburizing, nitriding furnaces | Step up when stress-corrosion cracking in chloride is the controlling failure mode |
| Inconel 625 | N06625 | Salt-water + acid + high-temp | Step up when both corrosion and high-temp are demanded simultaneously |
| Hastelloy X | N06002 | Combustion + gas turbine | Step up for gas turbine combustor cans and aerospace high-temp service |
| Haynes 230 | N06230 | Long-term to 1149 deg C | Step up for extreme creep at the top of the nickel-superalloy envelope |
| 310H stainless | S31009 | up to 1100 deg C oxidation | Lower-cost alternative when creep strength is not controlling; carburization risk |
Incoloy 800H Frequently Asked Questions
Q. What is the difference between Incoloy 800, 800H and 800HT?
The three are the same Ni-Fe-Cr base chemistry differentiated by carbon content and Al+Ti window. Standard Incoloy 800 (UNS N08800) is the baseline alloy for general heat resistance below 650 deg C (1200 deg F). Incoloy 800H (UNS N08810) carries controlled carbon 0.05 to 0.10 percent and ASTM grain size 5 or coarser to qualify for sustained service to 815 deg C (1500 deg F) under ASME Section VIII design tables. Incoloy 800HT (UNS N08811) adds the combined Al plus Ti window of 0.85 to 1.20 percent to extend creep-rupture strength to 982 deg C (1800 deg F).
Q. Is Incoloy the same as Inconel?
No. Incoloy is a nickel-iron-chromium family with iron as the matrix base (30 to 35 percent Ni, balance Fe). Inconel is a nickel-chromium family with nickel as the matrix base (above 50 percent Ni). The two are different alloy classes with different specifications, different welding procedures and different price levels. Incoloy 800H is not interchangeable with Inconel 600 or 625 even where the operating temperature envelopes overlap.
Q. Is Incoloy 800H ASME-code qualified?
Yes. Incoloy 800H is listed in ASME Section II Part B as SB-407 (seamless pipe and tube), SB-408 (rod and bar), SB-409 (plate, sheet and strip) and SB-564 (forgings) with maximum design temperature 815 deg C (1500 deg F) for Section VIII Division 1 pressure-vessel service. Higher-temperature service is permitted under ASME Code Cases for specific applications.
Q. Do you supply Incoloy 800H with EN 10204 type 3.2 certification?
Yes. Type 3.1 is supplied by default with heat number, chemistry, solution-anneal cycle, mechanical results, grain size verification and dimensional report. Type 3.2 with Lloyds Register, DNV, BV, SGS or TUV witness is supplied on call-out and is standard practice on refinery and petrochemical procurement.
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