Cheng, FrankYang, Yao2016-08-102016-08-1020162016Yang, Y. (2016). Studies of Circumferential Stress Corrosion Cracking of Pipelines (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27912http://hdl.handle.net/11023/3175The circumferential stress corrosion cracking (C-SCC) of X46 and X65 steels in a near-neutral pH environment was studied in this work. The steels were found to be susceptible to SCC. The corrosion and cracking behavior of the steels were investigated. The anodic dissolution at the crack tip was enhanced by stress, contributing to the crack propagation. The increase of corrosion rate was associated with the porous corrosion product. The mechanism of SCC was found to be stress dependent. The SCC process was anodic dissolution dominant under a low stress, while the process was mechanical fracture dominant under a sufficiently high stress. The different SCC behaviors between the steels were studied. Compared with X65 steel, X46 steel contained pearlite and has larger grain size, resulting in better adhesion of corrosion product on the steel and lower mechanical strength. Therefore, X46 steel is more susceptible to mechanical fracture, instead of corrosion.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Materials ScienceEngineering--Mechanicalcircumferential stress corrosion crackingpipelinesstress enhanced corrosioncrack propagation ratemaster thesis10.11575/PRISM/27912