The effect of the charging time and current density of the electrochemical hydrogen charging process, as well as the crystallographic structure of the steel on the hydrogen embrittlement sensitivity of stainless steels were assessed via slow strain rate tensile test. The results showed that for ferritic stainless steel, with the increase of hydrogen charging time and current density, the plasticity decreases significantly, and the sensitivity of hydrogen embrittlement increases greatly. The SEM observation results of the fracture morphology show that the fracture type changed from ductile fracture to brittle fracture. As a contrast, under the same conditions, the sensitivity of hydrogen embrittlement of austenitic stainless steel was lower, and the resistance of hydrogen embrittlement was higher. It was found that there was a large amount of hydrogen on the surface of the tested steel after hydrogen charging, and the hydrogen content gradually decreased with the depth of the sample. As hydrogen traps, grain boundaries may affect the hydrogen embrittlement sensitivity of steels.

Keywords： electrochemical hydrogen charging ; ferritic stainless steel ; austenitic stainless steel ; hydrogen embrittlement sensitivity