Ferritic tempered steels have a ferrite microstructure like carbon steel, which is a body-focused cubic precious stone construction, and contain somewhere in the range of 10.5% and 27% chromium with almost no or no nickel. This microstructure is available at all temperatures because of the chromium expansion, so they are not hardenable by heat treatment. They can't be reinforced by chilly work similarly as austenitic hardened steels. They are attractive.
