Evaluation of the active mechanism for acidic SCC induced mechanical degradation : a methodological approach

This work evaluates the mechanical degradation of Dual Phase steel due to acidic stress-corrosion cracking (SCC). The SCC susceptibility is studied by in-situ constant extension rate testing, followed by post-mortem fractographic evaluation, while the corrosion rate is determined by electrochemical measurements. Elevating the temperature results in a decrease in both strength and ductility. Organic acids addition further leads to a significant ductility loss, whereas oxygen removal yields a ductility gain. The corrosion rate shows a linear relationship with the H+ concentration. Between a pH of 4.2-7, anodic dissolution occurs, whereas hydrogen absorption takes place at lower pH, causing hydrogen-assisted stress-corrosion cracks