Ferritic stainless steel has a similar ferrite structure to carbon steel, a body-centered cubic crystal structure, with a chromium content ranging from 10.5% to 27%, and very little or no nickel.
Due to the addition of chromium, this microstructure is present at all temperatures, so they cannot be hardened by heat treatment. They cannot be strengthened to the same degree by cold working as austenitic stainless steels. They are magnets.
Because they contain almost no nickel, they are cheaper than austenitic steel and are found in many products; Type 439 and Type 441 are used for Building components for European building and structural applications (Type 430 with 17% Cr)
