Influence of tensile pre-strain and sensitization on passive films in AISI 304 austenitic stainless steel

The degree of sensitization for tensile pre-strain (0%, 10%, 20%, 30%, 40%) of AISI 304 stainless steels and sensitization at 575 °C was investigated by the double loop electrochemical potentiokinetic reactivation technique and scanning electron microscopes (SEMs). The properties of passive films of all the sensitized specimens in borate buffer solution (pH = 9.2) with 5000 ppm Cl− were investigated by the Mott–Schottky analysis. The degree of sensitization results showed that two reactivation current peak values were obtained for the sensitized specimens after 30% and 40% pre-strain. The degree of sensitization was decreased by pre-strain, except for specimen with 10% pre-strain. The results were further confirmed by the Mott–Schottky analysis.