| Abstract: | Hydrogen blistering, hydrogen‐induced plasticity loss (HIPL) under slow strain rate test and hydrogen‐induced cracking or fracture (HIC) under constant load for rail steel were evaluated. The threshold diffusible hydrogen concentrations for blistering, HIPL and HIC were 2.03 ppm, 0.26 ppm and 0.24 ppm, respectively. During charging, blistering formed first and fissure initiated at the wall of the blistering. HIPL (lδ) was found to decrease linearly with the reciprocal of the diffusible hydrogen concentration (C0), i.e. lδ = 105 ‐ 27/C0. The threshold stress for HIC (σc) in MPa decreases linearly with In C0 in ppm i.e., σc = 642 ‐ 284 In C0. |
