Strain-induced preferential dissolution at the dislocation emergences in MnS: an atomic scale study

The long-standing problem of dislocation-preferential dissolution in a crystal has been generally ascribed to the distortion energy stored in the vicinity of the dislocation core. However, due to lack of experimental means, the relationship between the local distortion state and the electrochemical behaviour of a single dislocation has not been established so far. via in situ ex-environment transmission electron microscopy (TEM), we demonstrate that the emergences of both edge and screw dislocations on MnS surfaces are the preferential sites for dissolution of the MnS inclusions within a stainless steel. In addition, we map the strain-induced variation of the standard electrode potential around the edge dislocation by a combination of the aberration-corrected high-resolution TEM and strain-analysis-based mechanochemistry theory. Significantly, our report provides a new approach to investigate the strain-corrosion correlation at an atomic scale.