For improved surface quality, formability, corrosion, and wear resistance, NITRONIC Alloys are divided into the 200 and 300 series and include between 16 and 30 percent chromium and 2 to 20 percent nickel. Heat treatment isn't an option for hardening austenitic metals. Because of their better formability and corrosion resistance, these stainless steels are the most extensively used grades. In their annealed condition, all austenitic steels are nonmagnetic. When cold worked, some austenitics can be mildly magnetic, depending on their composition.