UNS S31254 (254 SMO) is a high-alloy austenitic stainless steel known for its exceptional resistance to chloride-induced corrosion, pitting, and crevice corrosion. It was originally developed to address the needs of industries operating in harsh marine and chemical processing environments where conventional stainless steels, like 316L, fall short. With a combination of high molybdenum and nitrogen content, UNS S31254 (254 SMO) offers a superior solution for resisting corrosion, making it ideal for demanding applications in the oil and gas, chemical processing, pulp and paper, and marine industries.

The steel combines moderate mechanical strength (typically over 300 MPa yield strength) and high ductility with excellent corrosion resistance in seawater and a variety of industrial environments. Typically the alloy has a PREn (Pitting Resistance Equivalent) of 42-44 which ensures that the resistance to pitting corrosion is high. In addition, the steel provides good resistance to crevice corrosion. Ambient and sub-zero temperature notch ductility is very good. These attributes mean that this high molybdenum stainless steel can be