Local mechanical-electrochemical behaviour of duplex stainless steels: a novel approach for mapping precursor sites for pitting corrosion

摘要

The influence of residual surface stresses generated by polishing on the pitting susceptibility of duplex stainless steels was studied by combining microelectrochemical measurements with thermal-mechanical simulation. It has been shown that the surface stress state was the driving force for pit initiation along the austenite/ferrite interface. The local stress gradient was the key-parameter in pit initiation and the local average stress was the parameter governing the transition from metastable to stable pitting.