Comparative Study of Hydrogen Embrittlement of Three Heat-resistant Cr-Mo Steels Subjected to Electrochemical and Gaseous Hydrogen Charging

Abstract

Hydrogen embrittlement (HE) behaviors of low carbon steel and three heat-resistant Cr-Mo steels having different Cr contents were compared through tensile testing, silver decoration, and blistering observation after electrochemical hydrogen charging and hardness testing after gaseous hydrogen charging. It was observed that higher Cr content caused a longer suppression in charging hydrogen into the steels. However, under hydrogen supersaturation conditions, the higher the strength of the heat-resistant steels, the poorer the HE resistance after electrochemical charging. In contrast, the higher the Cr content, the better the HE resistance under high-temperature gaseous charging conditions.