309S stainless steel pipe

309S is a free-cutting stainless steel containing sulfur, used where easy cutting and high surface finish are primarily required.

The corresponding Chinese brand of 309S is 0Cr23Ni13, American standard S30908 (American AISI, ASTM) characteristics and uses: corrosion resistance and heat resistance are better than 0Cr19Ni9.

309s is a variant of 309 stainless steel with a lower carbon content and is used where welding is required. The lower carbon content minimizes the precipitation of carbides in the heat-affected zone close to the weld, and the precipitation of carbides may cause intergranular corrosion (welding erosion) of stainless steel in certain environments.

Alloys 309 and 309S are austenitic chromium-nickel stainless steels typically used in higher temperature applications. Due to their high chromium and nickel content, Alloys 309 and 309S are highly corrosion-resistant, have excellent resistance to oxidation and have excellent heat resistance while providing good strength at room and elevated temperatures. The only significant difference between 309 and 309S is the carbon content. Alloy 309S contains much less carbon, minimizing carbide precipitation and improving weldability.