Ferritic stainless steel

They are characterized by being magnetic, non-hardenable by heat treating, and having excellent resistance to stress-corrosion cracking (SCC).

By comparison with austenitic stainless steels, these are less hardenable by cold working and less weldable, but more cost-effective due to the lower nickel content.

Canadian-born engineer Frederick Mark Becket (1875-1942) at Union Carbide industrialised ferritic stainless steel around 1912, on the basis of "using silicon instead of carbon as a reducing agent in metal production, thus making low-carbon ferroalloys and certain steels practical".

Where the Cr, Mo, and N, terms correspond to the contents by weight % of chromium, molybdenum and nitrogen respectively in the steel.

Compared to austenitic stainless steels, they offer a better thermal conductivity, a plus for applications such as heat exchangers.