Microstructural change and corrosion variation of SAPH440 steel induced by pre-deformation

Abstract

The influence of microstructural variation on corrosion of SAPH440 steel induced by pre-deformation has been investigated in the corrosive solution. The microstructure observation was carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The corrosion was characterized by weight loss method (WLM), open circuit potential (OCP) and potentiodynamic polarization curve (PPC) measurements. The results show that compared to the as-received specimens, the corrosion potential moves to the negative direction and corrosion current density increases after pre-deformation. The corrosion susceptibility is enhanced by the pre-deformation behavior, which is attributed to the increase in dislocation density with the increasing tensile elongation.