Investigation on stress corrosion cracking of API 5L X65 steel in CO2 corrosion medium

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2021-09, Vol.824, p.141856, Article 141856
• Main Authors: Sadeghi, Mohammad Amin, Javidi, Mehdi
• Format: Article
• Language: English
• Subjects: Anodic dissolution; Carbon dioxide; CO2 corrosion; Corrosion; Corrosion effects; Corrosion rate; Dissolution; High strength low alloy steels; Hydrogen involvement; Potentiodynamic polarization; Slow strain rate; Slow strain rate tensile test; Stress corrosion cracking; Surface properties; Temperature; Temperature effects; Tensile tests
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2021.141856

This investigation studied the simultaneous effect of temperature (in the range of 30–70 °C) and NaCl concentration (in the range of 1–20 wt%) on stress corrosion cracking behavior of API 5L X65 steel in CO2 corrosion medium. The results of slow strain rate tensile test and surface characterization revealed that SCC susceptibility increased by an increase in temperature and a decrease in NaCl salt concentration. Furthermore, potentiodynamic polarization technique was employed in case of condition with the highest SCC susceptibility and illustrated that contribution of anodic dissolution and hydrogen involvement was the main SCC mechanism. •SCC susceptibility of X65 steel in CO2 saturated NaCl solution were investigated.•SCC susceptibility increases with increasing temperature and decreasing NaCl.•Harshest condition and the most SCC susceptibility was for 1 wt% NaCl at 70 °C.•Anodic dissolution and hydrogen involvement are the dominant SCC mechanism.•Fracture surface showed ductile fracture at high salt/brittle fracture at high T.