Introductions

Incoloy 800H Alloy (UNS N08810 / W.Nr. 1.4958) is a controlled‑composition, austenitic nickel-iron-chromium alloy developed for high‑temperature structural applications requiring superior creep resistant performance. The alloy contains 30–35% nickel, 19–23% chromium, with the balance iron, and features controlled carbon content of 0.05–0.10%—in the upper range of standard Incoloy 800—solution annealed at 2100–2150°F to achieve ASTM grain size 5 or coarser for optimal creep‑rupture strength. This heat resistant alloy 800H delivers excellent oxidation resistance up to 1100°C (2010°F), superior carburization resistance, and maintains useful strength above 600°C (1112°F), making it the preferred material for heat exchangers, petrochemical reformer tubes, furnace equipment, ethylene cracking furnaces, power generation, hydrogen production, and pressure vessels. Available in Incoloy 800H plate, sheet, seamless pipe, tube, bar, round bar, wire, forgings, flanges, fittings, and fasteners, in hot rolled, cold rolled, cold drawn, annealed, and solution annealed conditions.

Chemical compotents（%）

Mechanical properties

Physical properties

Incoloy 800H Available Products and Standard

1. GB/T 15007 (Nickel and Nickel Alloy Plate, Strip, and Foil)

Domestic Grade: NS112 (GB/T 15007) / Incoloy 800H equivalent

Type: Sheet / Plate / Strip / Wire / Tube / Bar

Size Range:

• Incoloy 800H Alloy Wire: 0.1 – 15.0 mm dia

• Incoloy 800H Alloy Strip: 0.05 – 5.0 mm thick × 5 – 500 mm wide

• Incoloy 800H Alloy Round Bar: 8 – 355 mm dia

• Incoloy 800H Alloy Sheet / Plate: 0.5 – 180 mm thick

• Incoloy 800H Alloy Seamless Tube / Pipe: Custom sizes available

Surface: Annealed, Bright, Pickled, Ground

Testing: Chemical analysis, mechanical test (tensile strength, yield strength, elongation), hardness test, intergranular corrosion test, high-temperature creep test, dimensional inspection

2. ASTM B407 (Standard Specification for Nickel-Iron-Chromium Alloy Seamless Pipe and Tube)

Grade: UNS N08810 / Incoloy 800H / Alloy 800H / W.Nr. 1.4958

Type: Seamless Pipe / Seamless Tube / Heat Exchanger Tube

Size Range:

• Incoloy 800H Alloy Seamless Pipe: 6 – 610 mm OD × 1 – 50 mm wall thickness

• Incoloy 800H Alloy Seamless Tube: Custom sizes

Surface: Annealed, Pickled, Bright

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hydrostatic test, eddy current test, creep rupture test (optional), dimensional inspection

3. ASTM B408 (Standard Specification for Nickel-Iron-Chromium Alloy Rod and Bar)

Grade: UNS N08810 / Incoloy 800H / Alloy 800H

Type: Round Bar / Rod / Wire

Size Range:

• Incoloy 800H Alloy Round Bar: 8 – 355 mm dia (hot rolled or cold drawn)

• Incoloy 800H Alloy Wire: 0.1 – 15.0 mm dia (coils or straight)

Surface: Annealed, Pickled, Ground, Turned, Bright

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hardness test, ultrasonic test, dimensional inspection

4. ASTM B409 (Standard Specification for Nickel-Iron-Chromium Alloy Plate, Sheet, and Strip)

Grade: UNS N08810 / Incoloy 800H / Alloy 800H

Type: Sheet / Plate / Strip

Size Range:

• Incoloy 800H Alloy Sheet / Plate: 0.5 – 180 mm thick (hot rolled or cold rolled)

• Incoloy 800H Alloy Strip: 0.05 – 5.0 mm thick × up to 500 mm wide (coils)

Surface: Annealed, Pickled, Bright, Polished

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hardness test, intergranular corrosion test, high-temperature creep test, dimensional inspection

Applications

1. Petrochemical Industry & Reformer Tubes

• For reformer outlet piping, transfer lines, and steam reformer manifolds, Incoloy 800H delivers creep resistance and oxidation/carburization resistance at 550–800°C. The controlled carbon and coarse grain structure provide superior creep‑rupture strength compared to standard 800.

• For ethylene cracking furnaces and pyrolysis units, Alloy 800H tube withstands thermal cycling, high internal pressures, and aggressive carburizing atmospheres.

2. Heat Exchangers & Process Piping

• For shell‑and‑tube heat exchangers, superheater tubing, and reboiler bundles, Incoloy 800H provides oxidation resistance and thermal stability at elevated temperatures.

• For high‑temperature process piping, UNS N08810 pipe handles temperatures up to 1100°C while resisting oxidation, carburization, and nitridation.

• For furnace equipment including fans, muffles, fixtures, and radiant tubes, heat resistant alloy 800H delivers high‑temperature strength and oxidation resistance for long‑term thermal processing service.

3. Power Generation & Hydrogen Production

• For power generation superheater and reheater tubing, Incoloy 800H offers oxidation resistance and maintains mechanical properties at elevated temperatures.

• For hydrogen production and ammonia synthesis, Incoloy 800H pipe is specified for primary and secondary reformer tubes, transfer lines, and outlet manifolds where resistance to high‑temperature hydrogen attack is critical.

4. Industrial Heating Equipment & Pressure Vessels

• For furnace linings, heat‑treating equipment, and thermal processing components, Incoloy 800H plate and sheet provide resistance to oxidation and carburization.

• For ASME‑coded pressure vessels in high‑temperature corrosive service, ASTM B409 Incoloy 800H plate combines fabricability with elevated‑temperature strength and oxidation resistance.

FAQ – Incoloy 800H Alloy

Q: What is the difference between Incoloy 800, 800H, and 800HT?

A: Incoloy 800H alloy (UNS N08810) has controlled carbon content (0.05–0.10%) and is solution annealed at higher temperatures (2100–2150°F) to achieve ASTM grain size 5 or coarser, providing superior creep resistant Incoloy 800H properties above 1100°F (593°C). Incoloy 800 (UNS N08800) has lower carbon (0.08% max) and lower annealing temperature, making it suitable for short‑term high‑temperature exposure. Incoloy 800HT (UNS N08811) has controlled carbon with aluminum and titanium addition (≥0.85% Al+Ti) for maximum creep‑rupture strength. For service temperatures above 1100°F where creep resistance is critical, 800H is preferred; for the most demanding applications, 800HT is specified.

Q: What is the maximum operating temperature for Incoloy 800H?

A: Incoloy 800H alloy is suitable for continuous service up to 1100°C (2010°F). The controlled carbon content and coarse grain structure provide optimum creep and rupture strength above 600°C (1112°F). For maximum ductility, this grade should be used above 700°C (1290°F). The alloy maintains good oxidation resistance and structural stability across the entire elevated temperature range.

Q: What industries commonly use Incoloy 800H?

A: Petrochemical industry (reformer tubes, transfer lines, outlet manifolds, ethylene cracking furnaces), chemical processing (heat exchangers, process piping, reactors), power generation (superheater and reheater tubing), nuclear industry (ASME Code‑recognized pressure vessels), industrial heating (furnace components, heat‑treating equipment), hydrogen production (steam methane reformers, ammonia synthesis), and pressure vessel manufacturing.

Q: What are the key ASTM standards for Incoloy 800H?

A: ASTM B409 covers Incoloy 800H plate, sheet, and strip; ASTM B407 covers seamless pipe and tube; ASTM B408 covers bar, rod, and wire. All three standards require the material to be solution annealed at 1149–1177°C to achieve an ASTM grain size of 5 or coarser. ASME equivalents include SB409, SB407, and SB408 for pressure vessel applications.

We are a trusted Incoloy 800H Supplier and Incoloy 800H Manufacturer, China‑based, serving petrochemical plants, heat exchanger fabricators, furnace equipment builders, power generation contractors, and nuclear industry suppliers worldwide. All products comply with ASTM B409 / ASTM B407 / ASTM B408 / ASME SB409 with EN 10204 3.1 mill certificates, PMI verification, and dimensional inspection reports. We offer Incoloy 800H plate, sheet, seamless pipe, tube, bar, round bar, rod, wire, forgings, flanges, fittings, and fasteners in custom sizes, with cut‑to‑size, precision machining, and solution annealing services. Contact us at info@monokj.com for size chart, pricing, or custom requirements.