Alloy 31 is a nickel, chromium and molybdenum stainless steel with nitrogen and copper additions. It combines moderate tensile strength and high ductility with excellent corrosion resistance in sulfuric acid, reducing and oxidizing media and has strong resistance to corrosion and erosion corrosion in phosphoric environment.
Typically the alloy has PREN of ≥ 48, which ensure that the resistance to pitting corrosion is high.