EXPERIMENTAL STUDY ON HYDROGEN DIFFUSION AND HYDROGEN CORROSION IN STEEL PIPE

The steel pipe transporting hydrogen-containing atmosphere will suffer from hydrogen corrosion slowly and its performance downgrades. In this study, by analyzing the mechanism of atomic hydrogen permeation and diffusion, three commonly used steel pipes (20#, 16Mn and X52) were selected for Devanathane-Stachurski hydrogen permeation experiment. The morphology of steel after hydrogen permeation was analyzed by scanning electron microscope, and the changes of self corrosion potential and current before and after hydrogen permeation were compared by potentiodynamic polarization curve. The results show that the hydrogen diffusion coefficient of 20# steel is the largest and X52 is the smallest. With the increase of hydrogen charging current density and hydrogen charging time, the corrosion degree of steel also intensifies. The potentiodynamic polarization curve test shows that the self corrosion current of 16Mn increases by two orders of magnitude and the performance decreases obviously; X52 steel has good corrosion resistance and the performance degradation is the least.