Abstract
The influence of various negative half-wave alternating current (AC) densities on the stress corrosion cracking (SCC) behavior and mechanism of X80 pipeline steel (widely used in West-East natural gas transmission) was investigated in typical NS4 near-neutral solution (used to simulate the electrolyte trapped under a disbonded coating) by data acquisition technique, electrochemical method, immersion tests, slow strain rate tensile tests, and surface analysis techniques. It was found that the negative half-wave AC could accelerate corrosion of the steel for the potential decreasing, current density increasing and generating the local anodic dissolution such as nucleated pits. The SCC susceptibility of X80 steel was relatively high for disturbing the local double-charge layer structure at 5A·m−2 current density. Besides, the negative half-wave AC could promote cathodic hydrogen evolution reaction, the SCC susceptibility was low for hydrogen-induced plasticity at 10 and 20A·m−2 and the SCC mechanism was collectively controlled by anodic dissolution (AD) and hydrogen embrittlement, but it was elevated for the hydrogen-induced local anodic dissolution and hydrogen-induced embrittlement above 30A·m−2 and the SCC mechanism was hydrogen embrittlement.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
