Hangbo Alloy Group
Shanghai · Est. 2012
N08802 technical guide: nominal chemical composition, mechanical and physical properties, corrosion resistance, welding, product forms and ASTM standards...
Incoloy 802 (UNS N08802) is a nickel-iron-chromium alloy. High-carbon 800-type for carburising resistance. Ethylene-pyrolysis furnace workhorse. This guide covers its nominal chemical composition, typical mechanical and physical properties, corrosion behaviour, welding, common applications, available product forms and the ASTM standards that apply — everything a specifier needs to evaluate Incoloy 802 for a project.
Incoloy 802 belongs to the nickel-iron-chromium alloy class of materials. It is high-carbon 800-type for carburising resistance. It is ethylene-pyrolysis furnace workhorse. It is good oxidation resistance to 1000 °c.
Nominal (wt%) composition of Incoloy 802 (UNS N08802):
| Element | Composition (wt%) |
|---|---|
| Nickel (Ni) | 30.5 – 34.0 |
| Chromium (Cr) | 20.5 – 23.0 |
| Iron (Fe) | Balance |
| Titanium (Ti) | 0.6 – 1.2 |
| Aluminium (Al) | 0.3 – 0.8 |
| Carbon (C) | 0.30 – 0.60 |
| Manganese (Mn) | ≤ 1.5 |
| Silicon (Si) | ≤ 1.0 |
| Sulphur (S) | ≤ 0.015 |
| Copper (Cu) | ≤ 0.75 |
Typical physical properties:
| Property | Value |
|---|---|
| Density | 7.95 g/cm³ |
| Melting Range | 1300 – 1400 °C |
| Thermal Expansion (20–1000 °C) | 15.6 µm/m·K |
| Thermal Conductivity (100 °C) | 12.0 W/m·K |
| Modulus of Elasticity | 196 GPa |
Typical room-temperature mechanical properties (annealed / specified condition unless noted):
| Property | Typical Value |
|---|---|
| Tensile Strength (Rm) | 620 MPa (90 ksi) |
| Yield Strength, 0.2% (Rp0.2) | 275 MPa (40 ksi) |
| Elongation in 50 mm | 40% |
| Hardness (Rockwell B) | 75 – 90 HRB |
| Property | Value |
|---|---|
| Service temperature | Up to 1000 °C |
| High carbon for carburisation resistance | 0.30 – 0.60 % C |
802 is a high-carbon Ni-Fe-Cr alloy for high-temperature engineering. The elevated carbon improves carburisation and metal-dusting resistance, while the chromium gives good oxidation resistance. It is the traditional choice for ethylene-pyrolysis furnace components.
Welded with matching ERNiCrFe-?? or Incoloy 800H-type fillers; the high carbon means care is needed to avoid sensitising in the HAZ, so qualified procedures and often post-weld heat treatment are used.
The grade is supplied to the following common specifications:
| Standard | Product Form / Scope |
|---|---|
| ASTM B407 | Seamless pipe & tube |
| ASTM B408 | Bar & wire |
| ASTM B409 | Plate, sheet & strip |
| ASTM B366 | Fittings |
Standards & References. Specifications cited on this page; confirm current revisions with the issuing body.
General references: Nickel Institute · AMPP (corrosion) · SAE International · ASTM International
802 is a high-carbon version of the 800 family (Ni-Fe-Cr) developed for high-temperature service. The 0.30–0.60 % carbon improves resistance to carburisation and metal dusting, making it the classic ethylene-pyrolysis furnace alloy.
Annealed: ≈ 620 MPa tensile, ≈ 275 MPa yield, 40 % elongation, 75–90 HRB, serviceable up to about 1000 °C.
Both are Ni-Fe-Cr; 802 has much higher carbon (0.30–0.60 % vs ≤ 0.10 %) for carburisation/metal-dusting resistance in furnace tubes, whereas 800H is optimised for creep with controlled carbon and Ti/Al.
Yes, with 800H-type or matching fillers, but the high carbon requires a qualified procedure and often post-weld heat treatment to avoid HAZ sensitisation.
Ethylene pyrolysis furnace tubes and pigtails, retorts, radiant cups, furnace rollers and carburising fixtures.
ASTM B407 (seamless pipe/tube), B408 (bar/wire), B409 (plate/sheet/strip) and B366 (fittings).
As a dedicated nickel alloy manufacturer serving chemical processing, power generation, petrochemical sectors, Hangbo Alloy Group supplies the grades discussed here across all standard product forms with full ASTM/ASME documentation and EN 10204 3.1 certification. Our material is specified for applications where corrosion resistance, high-temperature strength, and traceable quality are non-negotiable. See our production & testing facilities for more on how every heat is verified.