The presence of absorbed hydrogen (H) within pure iron and most steels (including carbon and stainless steels) has been found to increase their corrosion. Historically, the enhanced corrosion of H-charged steels has been attributed to the ability of H to destabilize the passive film formed upon the metal. However, recent works have revealed that absorbed H can promote Fe dissolution even in non-passivating solutions. This indicates that the effect of H on metal corrosion could be "intrinsic," rather than through "extrinsic" mechanisms involving solely the destabilization of the passive film. In this review, the impact of absorbed H on the corrosion of different types of steels has been collated, summarized, and discussed. The influence of H on the pitting and environmentally assisted cracking mechanisms of steels has been elaborated. Some implications of H-assisted corrosion from an engineering perspective have also been discussed.
- Hydrogen assisted cracking
- Hydrogen-induced corrosion pitting
- Sulfide stress cracking