Determination of tensile stress induced by oxide film during corrosion process for α-Ti

Abstract

If a tensile stress generates at the metal/oxide film interface during natural corrosion, it will assist the applied stress to promote stress corrosion cracking (SCC). Such induced tensile stress has been reported during the anodic polarization of {alpha}-Ti in 0.1 mol/L H{sub 2}SO{sub 4} solution. In this study, the authors investigate the sign and magnitude of the internal stress generated during natural corrosion for {alpha}-Ti in the same solution under open circuit condition. In addition, the authors attempt to show that for all anodic dissolution controlled SCC systems, a large tensile stress will generate at the metal/passive film interface during natural corrosion. The induced stress can assist the applied stress to promote the dislocation emission and motion and make SCC nucleate in a lower applied stress range. But for the systems without SCC, the induced tensile stress is very small or compressive stress develops. If so, the mechanism of anodic dissolution controlled SCC can be clarified in the level of dislocation based on the in situ TEM observations.