Current Research on the Corrosion Fatigue Crack Propagation Rate of Pipeline Steels

Corrosion fatigue damage is one of the most serious fracture forms of oil and gas transmission pipeline steels, which can cause severe fracture and failure. Recently, the corrosion fatigue crack propagation behavior, mechanisms of several influencing factors and the modeling of the crack propagation rate have attracted much focus, and a number of new methods and theories have been proposed. However, the understanding in some aspects still remains controversial. The majority of the current crack propagation rate models, whose reliability was experimentally validated when they were applied to their specific materials/environment systems, are the amendment to the linear superposition model. By the modeling which could provide a theoretical support to the actual operation and protection of the pipelines, the life of pipeline steels could be predicted, and the effects of influencing factors could be quantified. In this article, the current research on some influencing factors and theoretical models of the crack propagation rate of pipeline steels is summarized and discussed, and the future research priorities and problems to be solved are prospected.