Electrochemical investigation of passive film in pre-deformation AISI 304 stainless steels

The electrochemical measures in deformed AISI 304 stainless steels ranged from 0% to 24% were investigated. With the increasing of the strain α′-martensite was gradually increasing. Moreover, the morphologies and densities of dislocations changed with increasing strain. The Mott–Schottky plots showed that the maximum total of donor and acceptor densities in passive film occurred in borate buffer solution when ɛ-martensite was most, while in borate buffer solution with 5000 ppm Cl− the maximum total of donor and acceptor densities occurred when the content of α-martensite was most. These results were proven by further impedance spectroscopy experiments.