American iron and steel institute (AISI) use three numbers to clarify different types of steel which are 200, 300, 400 and 600 series. According to the components which could be discriminate into “nickel-chromium-manganese, chromium-nickel and chromium series.” The main elements of austenitic stainless steel are nickel, chromium, manganese which divided to 200 and 300 series; the materials are non-magnetic normally but after cold processing will become slightly magnetic. 304 could be general use and have great corrosion resistance, processing and welding properties.
