Nickel Alloys Incoloy Alloy 800 N08800
Austral Wight Speciality Metals

 Product Data Sheet  Nickel Alloys

Alloy 800™, 800H™, 800HT™  UNS-N08800, N08810, N08811

Incoloy® Alloy 800™ is widely used in equipment that must have high strength and resistance to oxidation, carburisation and other harmful effects of high temperature exposure. For service requiring optimum creep and rupture properties, Incoloy 800H or 800 HT are used. The high contents of nickel and chromium in the alloys also give good corrosion resistance.

Chemical Composition

ASTM B407 – Seamless Pipe & Tube

ElementIncoloy 800Incoloy 800HIncoloy 800HT
39.50 min39.50 min39.50 min
0.10 max0.05-0.100.06-0.10
Aluminium + Titanium
ASTM Grain Size
Not Specified5 or Coarser

Specified Minimum Mechanical Properties

ASTM B407 – Seamless Pipe & Tube

Yield Strength
Tensile Strength
Incoloy 800, 800H, 800HTHot Finished, Annealed17045030
Incoloy 800Cold Worked, Annealed20552030


Incoloy 800 is a solid solution strengthened alloy of nickel, chromium and iron with small additions of aluminium and titanium. Incoloy 800H and Incoloy 800HT are developments of Incoloy 800, which give better performance at high temperature. ASME design codes give significantly higher design strengths for Incoloy H and HT than Incoloy 800, and allow their use to higher temperatures. AS1210 prequalifies Incoloy 800 for use to 800°C. ASME specifications allow the use of Incoloy 800 to 815°C, and of Incoloy 800H and 800HT to 982°C.

Typical Applications

Thermal processing equipment in industrial applications, such as baskets, trays, and fixtures. In chemical or petrochemical processing it is used for heat exchangers and piping systems in nitric acid media, especially where resistance to chloride stress corrosion cracking is required.


Incoloy 800/800H/800HT are solid solution nickel chromium iron alloys with small additions of aluminium and titanium to improve corrosion and oxidation resistance. They are used for high temperature service, where resistance to oxidation and carburisation are required. For optimum stress rupture properties, or for pressure vessel service above 815°C, Incoloy 800H or Incoloy 800HT should be used.


Austral Wright Metals can supply these alloys as plate, sheet and strip, rod and bar, seamless and welded tube and pipe, fittings, condenser & heat exchanger tube, forgings and forging stock.

Oxidisation Resistance

The chromium and nickel contents of the alloy give excellent oxidation resistance, good resistance to carburisation and resistance to sulphidation at low concentrations of oxidising and reducing sulphur. The alloy also has reasonable resistance to nitridation in cracked ammonia, but falls short of the resistance of Inconel 600.

Variation of Tensile Properties with Temperature

Nickel Alloys Incoloy AlloyIncoloy Alloy 800 N08800

Variation of tensile properties with temperature for Incoloy 800

Variation of tensile properties with temperature for Incoloy 800HT

Corrosion Resistance

Incoloy 800/800H/800HT is generally free from both chloride stress corrosion cracking and intergranular corrosion caused by sensitisation. The alloy can be used in sea water. Incoloy 800/800H/800HT has resistance to acids similar to austenitic stainless steels. It has excellent resistance to both oxidising and non oxidising salts, except for halide salts, where pitting may occur. Please consult Austral Wright Metals for advice on your specific application.


Incoloy 800/800H/800HT can be readily hot worked. Forging is finished above 870°C, and air cooled. The work is then solution annealed. The alloys can be cold formed similarly to stainless steel but deformation forces are higher.


Incoloy 800/800H/800HT are “C” class alloys, difficult to machine. Heavy machines, sharps, slow speeds and deep cuts to remove the work hardened layer are needed.


Incoloy 800/800H/800HT are readily welded by the SMAW (manual), GMAW (MIG), GTAW (TIG) and SAW processes. Preheat or post heat and post weld heat treatment are not needed. Contamination of the weld pool should be prevented. Argon is used as the shielding gas.

Welding Consumables

Incoloy 800Incoloy 800HT
RecommendedINCO WELD AInconel FM 82INCO CORED 82DHInconel WE 117Inconel FM 617
Higher StrengthInconel WE 112Inconel FM 625INCO CORED 625DHInconel WE 117Inconel FM 617
Better Corrosion ResistanceInconel WE 182Inconel FM 82INCO CORED 82DHInconel WE 117Inconel FM 617

Heat Treatment

Incoloy 800 is solution annealed at 980°C, then rapidly cooled. Appreciable grain growth will occur if this temperature is exceeded. Incoloy 800H and 800HT are annealed at is 1150 – 1200°C to grow the grain size to ASTM 5.

Equivalent Specifications

FranceAFNORZ 8 NC 32.21

Physical Properties

Metric Units
7,940 kg/m³ @ 20°C
Melting Range
Electrical Resistivity
0.989 micro-ohm . m @ 20°C
Specific Heat
460 J/kg . °C @ 20°C
Mean Coefficient of Expansion
14.4 x 10-6 / °C @ 20°C
Thermal Conductivity
11.5 W / m . °C @ 20°C
Curie Temperature
Modulus of Elasticity
196.5 GPa @ 20°C
73.4 GPa @ 20°C
Poisson’s Ratio
0.339 @ 20°C
Magnetic Permeability
1.014 @ 200 Oe

ASTM Product Specifications

Seamless Nickel and Nickel Alloy Condenser and Heat Exchanger Tubes
Factory Made Wrought Nickel and Nickel Alloy Fittings
Nickel Iron Chromium Alloy Seamless Pipe and Tube
Nickel Iron Chromium Alloy Rod and Bar
Nickel Iron Chromium Alloy Plate, Sheet and Strip
Welded Nickel Iron Chromium Alloy Pipe
Welded UNS N08120, N08800, N08810 and UNS N08811 Alloy Tubes
Nickel Alloy Forgings
General Requirements for Nickel and Nickel Alloy Welded Tube
General Requirements for Nickel and Nickel Alloy Welded Pipe
General Requirements for Nickel and Nickel Alloy Seamless Pipe and Tube
The technical advice and recommendations made in this Product Data Sheet should not be relied or acted upon without conducting your own further investigations, including corrosion exposure tests where needed. Please consult current editions of standards for design properties. Austral Wright Metals assumes no liability in connection with the information in this Product Data Sheet. Austral Wright Metals supplies a comprehensive range of stainless steels, copper alloys, nickel alloys and other high performance metals for challenging service conditions. Our engineers and metallurgists will be pleased to provide further data and applications advice.