ATI 840™ alloy is a titanium- and aluminum-bearing austenitic stainless steel offering elevated-temperature scaling resistance superior to conventional chromium-nickel stainless steels, such as Type 304. The oxidation resistance of ATI 840 alloy compares favorably with higher alloyed grades up to 1900°F (1038°C), making it a good candidate alloy for use in sheathing for electric heating elements, automotive emission control systems, and other applications where resistance to elevated temperature degradation is important.

APPLICATIONS
ATI 840 alloy is a common sheathing material for electrical resistance heating elements. It is suitable for this application due to its combination of formability, weldability, corrosion resistance, and oxidation resistance. The alloy composition results in the formation of a cosmetically desirable dark oxide layer during annealing in a gas-fired furnace. This oxide layer is retained during service due to the alloy's elevated chromium and nickel contents. The excellent environmental resistance of this alloy makes it suitable for other applications as well. For example, ATI 840 stainless has sufficient chromium and nickel to resist the corrosive environment present in automotive exhaust systems.