Incoloy 800 Round Bars, 800H, and 800HT are iron-nickel-chromium alloys with good strength and excellent resistance to oxidation and carburization in high-temperature exposure. These nickel steel alloys are identical except for the higher level of carbon in alloy 800H, and the addition of up to 1.20 percent aluminum and titanium in alloy 800HT. Incoloy 800 was the first of these alloys and it was slightly modified into Incoloy 800H. This modification was to control carbon (.05-.10%) and grain size to optimize stress rupture properties. Incoloy 800HT has further modifications to the combined titanium and aluminum levels (.85-1.20%) to ensure optimum high-temperature properties. The nickel alloy is dual certified (800H/HT) and combines the properties of both forms. Incoloy 800H/HT alloy was intended for high-temperature structural applications. The nickel content makes the alloys highly resistant to both chloride stress-corrosion cracking and to embrittlement from precipitation of sigma phase. The general corrosion resistance is excellent. In the solution annealed condition, alloys 800H and 800HT have superior creep and stress rupture properties.
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, Valves, fittings and other components exposed to corrosive attack from 1100-1800° F, Chemical and petrochemical processing, etc.