Direct observation of hydrogen-enhanced plasticity in super duplex stainless steel by means of in situ electrochemical methods

In situ electrochemical hydrogen charging in combination with atomic force microscopy and optical microscopy has been used to study the effect of hydrogen on the austenite phase in super duplex stainless steel. Observations showed that hydrogen charging results in an irreversible deformation of austenite. High residual tensile stresses form in austenite during quench annealing. These stresses, in combination with the activation of dislocation sources by hydrogen, result in formation of slip lines on the austenite surface during in situ hydrogen charging.