Effect of plastic strain on corrosion-induced hydrogen infusion and embrittlement behaviors of Zn-coated ultra-high strength steel sheet

This study examined the effects of plastic strain on the corrosion-induced hydrogen evolution, infusion, and embrittlement behaviors of ultra-high strength steel sheets with galvanized (GI) and galvannealed (GA) coatings. The tensile pre-straining of the coated steels did not increase the hydrogen permeation flux in the absence of applied cathodic polarization, in contrast to the case under cathodic polarization. This was closely associated with the rapid kinetics of corrosion scale formation under pre-strains, providing an inhibitory effect on the surface. From this aspect, the difference in the resistance to corrosion-induced hydrogen embrittlement between GI and GA-coated steels was mechanistically interpreted.