AM 355 is a chromium nickel molybdenum stainless steel which can be hardened by martensitic transformation and/or precipitation hardening. Alloy AM 355 has good resistance to atmospheric corrosion and to a number of other mild chemical environments. AM 355 may have an austenitic structure and formability similar to other austenitic stainless steels or a martensitic structure and high strength comparable to other martensitic stainless steels. High strengths may also be attained by cold working, and are maintained (whether produced by heat treatment or by cold work) at temperature up to 1000 °F(538 °C). This alloy has been used for blades, knives, industrial cutters, discs, rotors, shafts and in similar parts where high strength is required at intermediate elevated temperatures.
Corrosion resistance of the alloy is superior to that of other quenched-hardenable martensitic stainless steels and approaches the capabilities of chromium-nickel austenitic stainless steels. AM 355 is normally supplied in either the annealed or equalized and over-tempered condition.