Incoloy 800HT (UNS N08811 / W.Nr. 1.4959)

Incoloy 800HT (UNS N08811 / W.Nr. 1.4959) nickel-iron-chromium alloys that have the same basic composition as INCOLOY alloy 800 but with significantly higher creep-rupture strength. The higher strength results from close control of the carbon, aluminum and titanium contents in conjunction with a high temperature anneal. Used in chemical and petrochemical processing, power plants for super-heater and reheater tubing, industrial furnaces and heat-treating equipment.

Equivalent Grades

Trademark	GB	GOST	ASTM	UNS	DIN	W.Nr.	NF	BS	JIS	SS
Incoloy 800HT	NS1102 NS112	–	Incoloy 800HT	N08811	X10NiCrAlTi32-20	1.4959	–	NA15H	–	–

Chemical Composition, %

Alloy	C	Si	Mn	P	S	Cr	Ni	Al+Ti	Ti	Fe
Incoloy 800HT	0.06-0.10	≤0.10	≤3.00	≤0.03	≤0.02	19.0-23.0	30.0-35.0	0.25-1.20	0.15-0.60	≥39.5

Typical Physical and Mechanical Properties (RT, Solution annealed)

Density, g/cm3	Melting Point, ℃	Tensile Strength, MPa	Yield Strength, MPa	ELongation, %	Hardness, HB
8.00	1357-1375	531	200	52	–

Available Products and Specifications

Rod, Bar, Wire and Forgings	ASTM B408/ASME SB408, ASTM B564/ASME SB564, ISO 9723/9724/9725
Plate, Sheet and Strip	ASTM A240/A480/B409/B906/ASME SA240/SA480/SB409/SB906, ISO 6208
Pipe and Tube	ASTM B163/ASME SB163, ASTM B407/B829/ASME SB407/SB829, ASTM B514/B775/ASME SB514/SB775, ASTM B515/B751/ASME SB515/SB751, ISO 6207
Welding Product	–
Others	ASTM B366/ASME SB366(Fittings)

Features

Resistance to prolonged exposure to elevated temperatures
Excellent resistance to oxidation, sulfidation, and carburization
Added Carbon and annealing treatment allows for higher creep and rupture properties above 600℃
Resistant to high temperature corrosion
Readily machined by standard methods
Best joined/welded using products for high temperature situations
Resistance to aqueous corrosion at moderate temperatures

Applications

Chemical and Petrochemical Processing—process equipment for the production of ethylene, ethylene dichloride, acetic anhydride, ketene, nitric acid and oxy-alcohol
Petroleum Refining—steam/hydrocarbon reformers and hydrodealkylation units
Power Generation—steam super-heaters and high temperature heat exchangers in gas-cooled nuclear reactors, heat exchangers and piping systems in coal-fired power plants
Thermal Processing Fixtures—radiant tubes, muffles, retorts and fixtures for heat-treating furnaces