Effects of Hydrogen Charging Time and Pressure on the Hydrogen Embrittlement Susceptibility of X52 Pipeline Steel Material

The effects of hydrogen charging time and pressure on the hydrogen embrittlement (HE) susceptibility of X52 pipeline steel material are studied by slow strain rate tensile tests. The fracture morphologies of the specimens are observed by scanning electron microscopy. The HE susceptibility of the X52 pipeline steel material increases with an increase in both hydrogen charging time and hydrogen pressure. At a charging time of 96 h, the HE susceptibility index reaches 45.86%, approximately 3.6 times that at a charging time of 0 h. Similarly, a charging pressure of 4 MPa results in a HE susceptibility index of 31.61%, approximately 2.5 times higher than that at a charging pressure of 0.3 MPa.