Effect of hydrogen on the stress corrosion cracking behavior of X80 pipeline steel in Ku’erle soil simulated solution

Ping Liang1,2), Cui-wei Du1), Xiao-gang Li1), Xu Chen1), and Zhang liang1) 1) School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China 2) School of Mechanical Engineering, Liaoning Shihua University, Fushun 113001, China

摘 要：Hydrogen was a key factor resulting in stress corrosion cracking （SCC） of X80 pipeline steel in Ku’erle soil simulated solution. In this article, the effect of hydrogen on the SCC susceptibility of X80 steel was investigated further by slow strain rate tensile test, the surface fractures were observed using scanning electron microscopy （SEM）, and the fracture mechanism of SCC was discussed. The results indicate that hydrogen increases the SCC susceptibility. The SEM micrographs of hydrogen precharged samples presents a brittle quasi-cleavage feature, and pits facilitate the transgranular crack initiation. In the electrochemical impedance spectroscopy （EIS） measurement, the decreased polarization resistance and the pitting resistance of samples with hydrogen indicate that hydrogen increases the dissolution rate and deteriorates the pitting corrosion resistance. The potentiodynamic polarization curves present that hydrogen also accelerates the dissolution rate of the crack tip.

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