Scanning Kelvin probe force microscopy study on hydrogen distribution in austenitic stainless steel after martensitic transformation

•Hydrogen distribution in γ-SS after martensitic transformation was studied.•Hydrogen is proved to accumulate in γ adjacent to martensite (α′) by SKPFM.•The peak of hydrogen concentration in γ increases first and then decreases. Martensite (α’) usually plays an important role in the hydrogen embrittlement (HE) of metastable austenitic stainless steels (γ-SS). However, there is still controversy about the location of hydrogen accumulation after martensitic transformation in γ-SS. Scanning Kelvin probe force microscopy (SKPFM) combined with finite element analysis (FEA) have been used to study the hydrogen distribution and evolution in hydrogen-precharged γ-SS after martensitic transformation. It is found that hydrogen accumulates in austenite (γ) adjacent to α′ after the formation of α′. The peak of hydrogen concentration in γ induced by α′ increases first and then decreases as hydrogen diffuses further into γ.