AMS5871 Execution Standard

Introduction to Incoloy 800HT Material

Incoloy 800, 800H, and 800HT are nickel-iron-chromium alloys that exhibit good strength and excellent resistance to oxidation and carburization at high temperatures. These nickel-steel alloys are identical except for the higher carbon content in the 800H alloy and the addition of up to 1.20% aluminum and titanium in the 800HT alloy. Incoloy 800 was the first of these alloys, which was slightly modified to become Incoloy 800H. This modification was made to control carbon (.05-.10%) and grain size to optimize stress rupture properties. Incoloy 800HT underwent further modification with combined levels of titanium and aluminum (.85-1.20%) to ensure superior high-temperature performance. The nickel alloy is dual-certified (800H/HT), combining the characteristics of both forms. Incoloy 800H/HT alloys are suitable for high-temperature structural applications. The nickel content makes the alloy highly resistant to chloride stress corrosion cracking and embrittlement caused by sigma phase precipitation. General corrosion resistance is excellent. In the solution-annealed condition, alloys 800H and 800HT exhibit excellent creep and stress rupture properties.

Chemical Composition of Incoloy 800HT:

Physical Properties of Incoloy 800HT:

Mechanical Properties of Incoloy 800HT at Room Temperature:

Available in various specifications including plates, bars, strips, wires, discs, ring blanks, and ring forgings. Bars are supplied in forged-rolled condition, surface polished or turned; discs and ring blanks are supplied in forged condition; rings are supplied in solution-treated condition; plates are supplied after solution treatment, alkali pickling, straightening, and edge trimming; strips are delivered cold-rolled, solution-treated, and descaled; wires are supplied in solution-pickled coil or straight form, or solution-treated straight fine polished condition.