Susceptibility of X80 Pipeline Steel to Hydrogen Embrittlement in Coal Gas Environment Containing Hydrogen

The hydrogen embrittlement (HE) susceptibility of X80 steel in coal gas environment containing hydrogen was evaluated by slow strain rate test (SSRT), tension test of notched specimens and fracture morphology observation. The results show that HE susceptibility of X80 pipeline steel was increased in high-pressurized hydrogen environment, as the strength and plasticity both dropped. And the transverse direction was more sensitive to HE. Comparing the ratios of plastic index in high-pressurized hydrogen and atmospheric pressurized air, the loss of ductility was produced both in SSRT and in tension test of notched specimens, and the region in three-dimensional stress was subjected to a greater impact of hydrogen embrittlement.