The Effects of Strain on Stability of Passivation in Austenitic Stainless Steels: Comparison with Heat Treatment
The passive film mainly consists of oxides and hydroxide and is a key for corrosion protection of metallic materials. It increases the durability and performance of engineering components by spontaneous formation of effective, adherent barrier between the corrosive environment and a substrate. Herein, influence of plastic strain and after heat treatment on austenitic stainless steels was compared with the focus on stability of the passive film. The following materials were used in this study: Sanicro 28(tm) AISI 316 L, and AISI 304 L. These specimens were subjected to a true strain of 0.58. The conventional three electrode cell was used to record the anodic potentiodynamic polarization curves. The grain size and other misorientation parameters were extracted using electron backscattered diffraction (EBSD) Fourier transform infrared spectroscopy (FTIR) imaging was used for capturing chromium oxide (Cr2O3) peaks for all specimens. The average area of Cr2O3 peaks was compared with deformed and after heat treatment of 700 degC 30 min specimens. It was found that heat treated specimens exhibited slightly higher average area of Cr2O3 than deformed.
Experimental Techniques