Influence of cold work on electrochemical behavior of 316L ASS in PEMFC environment

The influence of cold work (CW) on electrochemical behavior of 316L ASS in PEMFC (0.5M H 2 SO 4 + 2 ppm HF at 70 °C) environment was investigated by microstructural observations, x-ray diffraction (XRD), polarization, electrochemical impedance spectroscopy (EIS) and Mott-Schottky (M-S) techniques. The XRD is used to analyze the increase in dislocation density and formation of α '-martensite with increasing CW degree. The EIS is used to find out the effect of substrate dislocation density on the film resistance. The EIS result show that with increasing CW, the diameter of depressed semi-circular arc and consequently film resistance decreased. This indicates the formation of highly disordered and porous film on CW. From PDP results, it is found that icrit, i p and i corr increased on increasing CW degree. Moreover, the direct relationship was drawn from the dislocation density of the substrate to the defect density of the passive film from M-S technique.