Effect of Hydrogen on the Mechanical Behaviour of 22-13-5 Stainless Steel at Room Temperature

A stable fcc 22-13-5 stainless steel was hydrogen charged by exposing it in 9.8 MPa hydrogen gas at 300 ℃ for 14 days. The concentration of hydrogen was determined tobe 651 ppm. The mechanical testing at room temperature shows that after hydrogen charging the yield strength of the steel increases and the behaviour of transient creep and stress relaxation become more intensive in comparable conditions. All the results can be interpreted qualitatively and part of the creep results can be quantitatively calculated by the theory of mobile dislocation density proposed by Alden. The analysis indicates that the essential effects of hydrogen are to obstruct the movement of dislocation, so that the strength and the inelastic visccaity of the steel increase.