A novel heat treatment for improving the hydrogen embrittlement resistance of a precipitation-hardened martensitic stainless steel

Application of the novel heat treatment significantly improves the PH13–8Mo steel hydrogen embrittlement (HE) resistance over that obtained by conventional heat treatment, while maintaining the mechanical properties. The mechanism of the proposed method is as follows: austenite captures hydrogen and the mechanical properties are improved by fine grain strengthening. The results of this study show that compared with the steel properties obtained by conventional peak-aged heat treatment, the novel heat treatment results in a reduction in the tensile strength from 1500 MPa to 1400 MPa, but a significant decrease in the HE susceptibility index (IHE) from 52% to 14%.