External Stress Corrosion Cracking Risk Factors of High Grade Pipeline Steel

Abstract

The influence weights of various sensitive factors, such as steel grade, applied potential, temperature and soil environment, on stress corrosion cracking behavior of high-grade pipeline steel were studied by means of orthogonal test at mixed level and slow strain rate test. The stress corrosion behavior of X80 pipeline steel in near neutral and high pH simulated soil solution under overprotection potential was observed by SEM. The results showed that the applied potential has the greatest weight on stress corrosion index of ISSRT, followed by temperature, steel grade and soil environment. X80 pipeline steel exhibits high stress corrosion sensitivity in near-neutral and high pH simulated soil solutions at applied potential of -1500mV, and its SCC mechanism is hydrogen embrittlement (HE). This study can provide guidance for practical engineering application of pipeline steel.