The three major series of stainless steels born in 1910 are austenite, ferrite and martensite respectively. From the perspective of chemical composition, they mainly belong to the two systems of Fe-Cr and Fe-Cr-Ni.
At present, there are more than 230 kinds of stainless steels that have been put into the market, of which about 80% are derivatives of austenitic stainless steel (18 Cr--8 Ni), while the remaining 20% are evolved from 13 Cr steel.
