Environmentally assisted cracking mechanism of pipeline steel in near-neutral pH groundwater

A modified Devanathan dual cell was used in environmentally assisted cracking (EAC) tests to independently control the concentration of dissolved hydrogen and anodic current density. The experimental evidence indicates that the corrosion may reduce the micro-hardness of steel, suggesting a dissolution-induced degradation of the mechanical properties in the surface layer. An EAC model is described in which surface micro-plastic deformation can be enhanced by the dissolved hydrogen and anodic dissolution, and plays a crucial role in cracking processes. The model can provide a reasonable prediction for the dependence of the cracking resistance of pipeline steel on the applied potential.