Correlation of martensite content and dislocation density of cold worked 316L on defect densities of passivating film in acidic environment

Abstract

Influence of cold work (CW) on volume of martensite (α') and rise in dislocation density was investigated by x-ray diffraction in the first stage. Then, the influence of CW on film resistance, passivation current density (ip) and corrosion current density (icorr) was investigated by electrochemical techniques. Also, mott-schottky (M-S) technique was used to investigate the semi-conducting behaviour and defect densities of passivating film. It is found that CW increase α' and dislocation density. It is also found that CW decreases charge transfer resistance (Rct) and increases ip and icorr. Drop in Rct suggests that the passivating film conductivity and consequently ip and icorr increased. Also, the relationship between the defects of the substrate and the defects of the passivating film and consequently its effect on icorr has been established.