Alloy 800 is an iron-nickel-chromium alloy with moderate strength and good resistance to oxidation and carburization at elevated temperatures.
Alloy 800H is a solution heat treated (2100¡ãF/1150¡ãC), controlled-carbon version of alloy 800 with improved elevated temperature properties. It has improved creep and stress-rupture characteristics in the 1100¡ãF (593¡ãC) to 1800¡ãF (982¡ãC) temperature range.
Typical applications for alloy 800 and 800H are – Heat exchangers and process piping; carburizing fixtures and retorts; furnace components; electric range heating-element sheathing; extruded tubing for ethylene and steam methane reforming furnaces; ammonia effluent coolers.
The principle di?erence between alloys 800H and 800HT is the restricted aluminum and titanium content in 800HT, which results in higher creep and stress rupture properties.
Alloy 800H/800HT is frequently used in applications that involve long-term exposure to elevated temperatures where resistance to oxidation, carburization and other types of elevated temperature corrosion is required.
ncoloy 800H Forgings have good strength and excellent resistance to oxidation, sulfidation and carburization at elevated temperatures.
Incoloy 800H Forgings are components manufactured from chromium nickel alloy with additions of aluminium, titanium and high carbon content.
Incoloy 800H is an iron-nickel-chromium alloy having the same basic composition as Incoloy 800, with significantly higher creep-rupture strength.
The higher strength results from close control of carbon, aluminum, and titanium contents in conjunction with a high temp anneal.
The 800H modification was to control carbon (0.05 to 0.10%) and grain size to (>ASTM 5) to optimize stress rupture properties.
800H, AT (Incoloy 800) is an austenitic heat resistant alloy designed for high temperature structural applications.
The strength of 800H is achieved by controlled levels of carbon, aluminum and titanium along with a 2100¡ãF minimum anneal to achieve a grain size of ASTM 5 or coarser.
800H is commonly welded using RA82 (ERNiCr-3) bare wire for applications under 1450¡ãF.
RA330-04 (N08334) bare wire offers a closer match of thermal expansion coefficient, and somewhat higher strength.
For maximum strength alloy 617 (ERNiCrCoMo-1) bare wire or 117 (ENiCrCoMo-1) covered electrodes are suggested.
To avoid possible stress relaxation grain boundary cracking of N08811 in applications above 1000¡ãF the welded fabrication may be heated 1650¡ãF for about one hour per inch of thickness or 30 minutes minimum then air cooled.
Incoloy 800H is a solution heat treated, carbon controlled version of its parent Alloy 800.
The point to note with the higher carbon version of the Incoloy 800H that the modified alloy comes with improved elevated temperature properties.
The Nickel Alloy 800H is known for its excellent cold forming characteristics.
NAS 800H (NCF 800H, UNS N08810)/NAS 800T (UNS N08811) are nickel-iron-chromium alloys that provide high strength and excellent resistance to oxidation and carburization at high temperatures
High creep strength is attained through control over crystal grains¡ªvia high temperature heat treatment, together with fine control over carbon, titanium, and aluminum content.
INCOLOY alloy 800 (UNS N08800, W. Nr. 1.4876) is a widely used material for construction of equipment requiring corrosion resistance, heat resistance, strength, and stability for service up to 1500¡ãF (816¡ãC).
Alloy 800 offers general corrosion resistance to many aqueous media and, by virtue of its content of nickel, resists stress corrosion cracking.
At elevated temperatures it offers resistance to oxidation, carburization, and sulfidation along with rupture and creep strength.
For applications requiring greater resistance to stress rupture and creep, especially at temperatures above 1500¡ãF (816¡ãC), INCOLOY alloys 800H and 800HT are used.
The emphasis of this alloy is placed on the fact that it is more resistant to aggressive forms of corrosion. In particular, Incoloy 800 shows very high resistance to corrosive compounds seen in aqueous environments.
INCOLOY alloy 800 is used in a variety of applications involving exposure to corrosive environments and high temperatures.
The inclusion of chromium in combination with nickel in its chemistry makes it resilient to chemical and environmental corrosion.
The alloy also exhibits resistance to physical deterioration, e.g. – surface pitting and cracking.
Incoloy 800 is a popular choice in the oil and gas industries because it can withstand sour gas and high chloride environments.