Thermodynamic analysis and experimental investigation of SCC in steel gas pipelines

摘要

SCC is considered as a crack propagation process which is strongly coupled with plastic deformation,diffusion and eelctrochemicla corrosion.this is a central point in the thermodynamic modeling of SCC. The crack layer theory is used to describe the crack growfth in steel pipelines.The process zone in SCC consists of several sub-zones i.e.,a small submicron core adjacent to hte crack tip dominated by eelctrochemicla processes and diffusion,and the macroscopic elasto-plastic deformaiton zone.SCC mechanisms under specific loading and environmental conditions must be studied to obtain informaiton that is requreid for thermodynamic modeling of SCC. Experimental investigation of micromechanisms of SCC and coupling between plastic deformation on one hand and diffusion and electrochemistry on another are reported.