Investigation of the surface reactivity on a 304L tensile notched specimen using scanning electrochemical microscopy

Local electrochemical reactivity around a notched tensile sample of 304L stainless steel under applied stress was investigated using scanning electrochemical microscopy (SECM). The plastic strain field around the notch was evaluated by finite element model (FEM). Microscopic observations of local plasticity related to grain morphology were correlated with the effective plastic strain field calculated with FEM around the notch root. Numerical results, surface observations and experimental electrochemical investigations showed the significant effect of plastic strain gradient on the surface reactivity. The effect of roughness induced by the triaxial plastic strain field around the notch was investigated with surface topography measurements.