309/309S stainless steel coil/strip is a high alloy austenitic stainless steel material with excellent high temperature oxidation resistance and corrosion resistance. It contains high chromium (about 22-24%) and nickel (about 12-15%) components, which can maintain stable mechanical properties and oxidation resistance in high temperature environment. 309S is a low carbon version of 309 with a lower carbon content (≤0.08%), which reduces the precipitation of carbides during welding and reduces the risk of intergranular corrosion.

These two materials are often used in high temperature equipment, such as furnace parts, heat treatment equipment, heat exchangers, and high temperature environments in the chemical and petroleum industries, and are particularly suitable for long-term use in high temperature oxidation and corrosive media.