SIRIUS 309 S grade is a fully austenitic stainless steel containing 23% Cr, and 13% Ni additions. The alloy is well known for its multi-purpose high temperature corrosion resistance behaviour.

Carbon additions are optimized in order to provide improved creep resistance properties. Alloy SIRIUS 309S can be easily welded.

With its high chromium and low nickel contents, the alloy is designed for high temperature applications up to 1000°C (1832°F) in sulphur containing atmospheres. Higher sulphur content in gases will result in lower maximum temperature of uses.

The alloy can be also used in slightly oxidizing atmospheres, nitriding, cementing conditions as well as with thermal cyclings, but the maximum temperature of use will be reduced.