Influence Law of Hydrogen Content in Coal Gas System on Hydrogen Embrittlement Sensitivity of X80 Pipeline Steel

The sensitivity of X80 steel in gaseous hydrogen environment was evaluated by tightened disk pressure test and notch slow strain tensile test combined with fracture analysis, and the change rule of hydrogen embrittlement sensitivity of X80 pipeline steel with the hydrogen content in hydrogen-containing coal gas environment was also studied. The results showed that the burst pressure ratio (p_He/p_H2) of X80 pipeline steel in the atmosphere of helium and hydrogen was 1~2, and X80 pipeline steel had certain hydrogen embrittlement sensitivity. When X80 pipeline steel was used in the environment containing hydrogen, it should be further evaluated according to the use environment. When the partial pressure of hydrogen was 0.36 MPa, the elongation after fracture and reduction of area of X80 pipeline steel were similar to those in air at normal temperature and pressure. When the partial pressure of hydrogen was higher than 0.36 MPa, with the increase of hydrogen partial pressure, the plastic loss of X80 pipeline steel increased, the fracture exhibited embrittlement, and the hydrogen embrittlement sensitivity increased.