ASTM B407 INCOLOY 800HT / UNS NO8811 NICKEL ALLOY SEAMLESS PIPE

Incoloy 800HT, also known as “Alloy 800HT”, is designated as UNS N08811 or DIN W.Nr. 1.4959. It is an iron-nickel-chromium alloy having the same basic composition as Incoloy 800 and Incoloy 800H but with significantly higher creep-rupture strength. The higher strength results from deliberate control of the carbon, aluminum, and titanium contents in conjunction with a high-temperature anneal. Used in chemical and petroleum processing, in power plants for superheater and reheater tubing, in industrial furnaces, and for heat treating equipment.

Incoloy 800HT is primarily used in applications with temperatures up to 1100° F, where alloys 800H and 800HT are normally used in temperatures above 1100° F where resistance to creep and rupture is required. The chemical balance allows the nickel steel alloy to exhibit excellent resistance to carburization, oxidation and nitriding atmospheres. Incoloy 800HT will not become embrittled even after long periods of usage in the 1200-1600° F range where many stainless steels become brittle. Excellent cold forming characteristics typically associated with the nickel-chromium alloys are exhibited with 800HT. When cold formed extensively the grain size produces a visibly undulated surface called “orange peel”. Incoloy 800HT can be welded by the common techniques used on stainless steels.

Chemical Composition

Mechanical Properties

Physical Properties

Application

• Sulphuric acid piping and vessels

• Phosphoric acid evaporators

• Pickling tank heaters, pickling tanks and equipment

• Chemical process equipment

• Propellor shafts

• Tank trucks

• Calorifiers

• Electrostatic precipitator electrodes

• Hot vessels for food, water and seawater,

• ammonium sulphate vessels

• Expansion bellows

• Marine exhaust systems

• Power station ash hoppers

• Industrial furnaces

• Heat-treating equipment

• Chemical and petrochemical processing

• Super-heater and re-heaters in power plants

• Pressure vessels

• Heat exchanger