The stress field dependency of martensitic transformation in metastable austenitic stainless steel

Many large hydrogen storage tanks worldwide are constructed from metastable austenitic stainless steel; however, their fracture properties remain insufficiently understood. This is because the strain-induced martensitic transformation is dependent on stress triaxialities η. The present study focuses on quantitatively evaluating the effect of different η on the α′ transformation. This study firstly utilizes SEM-EBSD due to the high spatial resolution. Three (η = 0.5, 0.33, 0) different conditions were investigated. The results regenerated the η dependency on α′ transformation. It also found out that the low η condition somewhat suppressed the α′ transformation with large grain size.