Lean-alloyed austenitic stainless steel with high resistance against hydrogen environment embrittlement

To address the upcoming austenitic stainless steel market for automotive applications involving hydrogen technology, a novel lean – alloyed material was developed and characterized. It comprises lower contents of nickel and molybdenum compared to existing steels for high – pressure hydrogen uses, for instance 1.4435 (AISI 316L). Alloying with manganese and carbon ensures a sufficient stability of the austenite at 8 wt.% of nickel while silicon is added to improve resistance against embrittlement by dissolved hydrogen. Investigations were performed by tensile testing in air and 400 bar hydrogen at 25 °C, respectively. In comparison to a standard 1.4307 (AISI 304L) material, a significant improvement of ductility was found. The materials concept is presented in general and discussed with regard to austenite stability and microstructure.