309 stainless steel is an austenitic stainless steel containing higher chromium and nickel content. 309 stainless steel has excellent corrosion resistance in various corrosive media, including acid, alkali, salt and other solutions, as well as organic solvents. It can still maintain good corrosion resistance at high temperatures. Moreover, it has good high-temperature strength and creep properties and can work stably for a long time in high-temperature environments. It is suitable for high-temperature equipment in aviation, chemical industry and other fields. 309 stainless steel can be formed and welded through various processing methods and has good processing performance. Lastly, 309 stainless steel is non-magnetic and suitable for manufacturing parts and components without magnetic requirements.