Corrosion Behavior of 13Cr and S13Cr Steel in Raw Gas from Underground Coal Gasification

Stress corrosion cracking tests and corrosion simulation tests were conducted on 13Cr and S13Cr (stainless) steel to investigate their sensitivity to stress corrosion cracking and corrosion behavior in high-temperature and high-pressure crude gas wellbore conditions. The results show that both samples had low stress corrosion sensitivity in a gas environment containing H₂, CO₂, H₂S, etc. at 550 ℃ and a total pressure of 10 MPa. No macroscopic or microscopic cracks were found in the four point bending samples. The simulated corrosion test results show that the corrosion resistance of S13Cr was better than that of 13Cr, and its uniform corrosion rate and localized corrosion rate were both lower than those of 13Cr. According to the NACE 0775 standard, it belonged to moderate corrosion, and after the simulated corrosion test, no high-temperature decarburization phenomenon was found on the surfaces of the two samples.