Ferritic Stainless Steel

It is the most abundantly utilized stainless steel and has ferritic structure as which it cann’t be heat-treated. This has high resistance against corrosion and oxidation. It is used in furnace as container of acids and trims of alitomobiles. Carbon content of ferritic steel varies from 0.08 to 0.2%, Cr from 12 to 20. Mn from 1 to 1.5% and Si is 1.0%. Martensitic Stainless Steel This steel has martensitic structure and thus hardness. This can be hardened by quenching. It is used for table wear, springs and blades of turbines, surgical instruments and tools like cutting blades. The composition is C-0.01 to 1.2%, Cr-I2 to 18%, Mn-l t3 1.2%, Si-0.05 to 1 .O, Nickel-1 .O to 2.0%. For surgical instruments 0.75% Mo is added. Free machining quality achieved big additional of 0.75% S.