High‐Strength Austenitic Stainless Steels for High‐Pressure Hydrogen Applications

Hydrogen embrittlement (HE) poses the risk of premature failure in high‐pressure hydrogen applications, such as storage tanks, pressure sensors, valves, pipes, and compressors. Especially, high‐strength martensitic or ferritic steels are most susceptible to hydrogen, which limits lightweight design for many future energy applications. Due to the utilization of hydrogen as a green energy carrier, efforts are made to improve the resistance of steels to HE at elevated pressures and low temperatures. For that purpose, a performance screening of high‐strength austenitic stainless steels is performed using slow strain rate testing. Different high strength austenitic stainless steels, such as Böhler P511/Nitronic 50, Böhler P513/Nitronic 60, Böhler P568, Böhler P569, and Böhler T200/A286, were tested and ranked with respect to the nickel and chromium equivalents and the martensite start temperatures M s and M d30 . The results were benchmarked with standard stainless austenitic grade 316L. It is shown that the austenite stability is the main factor of influence with respect to the HE susceptibility. Furthermore, the roles of chromium and nitrogen were evaluated and discussed. Finally, two new risk assessment maps are proposed, which allow a simplified classification of the HE resistivity based on the chemical composition, temperature, and strain.