STUDY ON GAS PHASE HYDROGEN PERMEATION AND HYDROGEN DAMAGE BEHAVIOR OF X80 PIPELINE STEEL

In this paper, gas phase hydrogen permeability test and slow strain rate tensile test were carried out for X80 pipeline steel in different hydrogen-doped environments, and combined with the method of micro-morphology analysis, hydrogen permeability and hydrogen damage behavior of X80 pipeline steel in hydrogen-doped environments were studied. The experimental results show that with the increase of hydrogen doping ratio, except for the hydrogen diffusion coefficient (D_eff), the other hydrogen permeation kinetic parameters show an increasing trend, which indicates that the hydrogen embrittance sensitivity of the pipe increases with the increase of hydrogen doping ratio. When hydrogen is added to 30%, the tensile strength of the pipe line steel does not change significantly compared with that of the atmospheric air environment, and the elongation and section shrinkage after fracture decrease, and the ductility of the pipeline decreases. The fracture edge of the notched tensile specimens showed brittle cleavage morphology, and the material underwent brittle transformation.