STUDY ON X52M PIPELINE AND WELD MECHANICAL PROPERTIES IN HYDROGEN-NATURAL GAS PIPELINE TRANSPORTATION

In this paper, by simulating a hydrogen doped environment with a total pressure of 6.3 MPa and 30%, slow strain rate tensile, fracture toughness and gas phase hydrogen penetration tests were carried out on the X52M base metal and girl-weld, and the performance degradation of the test steel in a hydrogen doped environment was analyzed. The results show that the mechanical properties of the test steel base metal and girth weld are lower than those in the air environment at a total pressure of 6.3 MPa and a hydrogen ratio of 30%. By analyzing the sensitivity of different mechanical properties to hydrogen, it is suggested that notched tensile strength loss and the area proportion of toughness area, combined with the crack tip opening displacement, evaluate the applicability of pipe in hydrogen doped environment.