Effect of hydrogen charging time on hydrogen blister and hydrogen-induced cracking of pure iron

Abstract

Hydrogen blister (HB) and hydrogen-induced cracking (HIC) of pure iron at various charging times were investigated. The results show that an increase in charging time leads to the increased HB height/width and HIC length/depth, and a change in hydrogen damage morphology. Subsurface HIC initiates and propagates along the grain boundaries, which makes the surface bend outwards to form blister on blister features, suggesting grain boundary cracking-induced blister-blister interaction mechanism. Crystallographic analysis demonstrates that adjacent grain boundary oriented-{100}//ND and {110}//ND exhibits the highest susceptibility to HIC, which offers a pathway to design hydrogen-resistant structural steels through the control of grain boundary.