The influence of residual stress on the initiation and propagation of trans-granular stress corrosion cracking in high-pressure natural gas transmission pipelines.

摘要

Trans-granular stress corrosion cracking is a phenomenon that occurs on the exterior surfaces of buried high-pressure steel pipelines that transport gas and other liquid hydrocarbons. Trans-granular stress corrosion cracking has been recognized as a significant contributor to the total leaks and ruptures experienced by the massive infrastructure of buried pipelines in North America. Currently, the exact mechanism of trans-granular stress corrosion cracking initiation and growth on pipelines surfaces, although theorized, is not well defined. Empirical evidence supports the action of an aqueous environment, a failed surface coating, a susceptible material and stress as necessary components for the initiation and growth of trans-granular stress corrosion cracking. Residual stress may be one source of stress that plays a role in the initiation and early stage growth of trans-granular stress corrosion cracking. This thesis will investigate the relationship between levels of residual stress and the location of trans-granular stress corrosion cracking initiation, early stage crack growth and cracking velocity.