Effect of Prestrain on the Fatigue Crack Initiation life of X60 Pipeline Steel
It is impossible to keep pipelines free from defects in the manufacturing, installation and servicing processes. In this paper, pre-tension deformation was used to imitate the defects of the part of material and the U-notch specimens were used to investigate the fatigue crack initiation life of X60 pipeline steel after pre-tension straining with ductile deformation of 0,5%,10% and 15%. Test results show that the prestrain had apparent straining hardening effects, but decreased the plasticity of pipeline steel. The prestrain prolonged the fatigue crack initiation life, and increased resistance coefficient and equivalent stress threshold of the fatigue crack initiation.
M. B. Chen and Y. R. Jiang, "Effect of Prestrain on the Fatigue Crack Initiation life of X60 Pipeline Steel", Advanced Materials Research, Vols. 311-313, pp. 841-844, 2011