Research on the Mechanism of Fatigue Crack Initiation of X60 Pipeline Steel after Per-Tension Deformation

Abstract:

It is impossible to keep pipelines free from defects in the manufacturing, installation and servicing processes. In this paper, pre-tension deformation of X60 pipeline steel was employed to experimentally simulate the influence of dents and the mechanism of fatigue crack initiation of X60 pipeline steel after per-tension deformation under cyclic loading were investigated. The results indicate that the mechanism of fatigue crack initiation is the typical cleavage fracture characteristics and the cracks mainly initiates from the non-metallic inclusions which was the local brittle fracture materials such as MnS inclusion. With the pre-tension deformation increase, the yield strength of the matrix was increased and the toughness decreased due to the work-hardening effect. With the effects of the non-metallic inclusions larger, the fatigue cracks initiated from the non-metallic inclusions easier.

• Periodical: Applied Mechanics and Materials (Volume 197)
• Pages: 798-801
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.197.798
• Online since: September 2012
• Authors: Yu Rong Jiang, Mei Bao Chen
• Keywords: Crack Initiation, Crack Source, Fatigue, Per-Tension Deformation, X60 Pipeline Steel

References

[1] Cosham A. and Hopkins P., in: The pipeline defect assessment manual, Fourth international pipeline conference, Pergamon, New York(2002) , in press.

DOI: 10.1115/ipc2002-27067

[2] Meibao Chen and Yurong Jiang: Progress in Safety Science and Technology Vol. VII (2008), p. (1919).

[3] Leis B.N. and Francini R. B., in: Final report on project PR 3-9305 to the Line Pipe Research Supervisory Committee of the Pipeline Research Council International, (1999).

[4] Edward D.C.: Engineering Research Station, Report 4080(1988), p.55.

[5] Hopkins P. and Corbin P., in: NG-18/EPRG seventh joint biennial technical meeting on line pipe research, Calgary, Alta., Canada, (1988).

[6] Miller A.G.: Int. J. Press Vessel Piping Vol. 32(1988), p.191.

[7] Maxey W.A., in: NG-18 Report No. 162. AGA Catalogue No. L51518, Battelle, (1986).

[8] Fowler J.R., Katsounas A.T. and Boubenider R., in: The America Gas Association Offshore Supervisory Committee and Pipeline Research Committee, AGA(1992), p.201.

[9] Fowler J.R., Alexander C.R., Kovach P.J. and Connelly L.M., in: EPRG/PRC 10th Biennial Joint Technical Meeting on Pipeline Research, Proceedings, vol. 1, Cambridge, UK(1995), pp.15-1.

[10] Batisse R., Meziere Y., Mokhdani C. and Pineau A., in: EPRG/PRC 10th Biennial Joint Technical Meeting on Pipeline Research, Proceedings, vol. 1, Cambridge, UK(1995), pp.16-1.

[11] Xiulin Zheng : Int. J. Fatigue Vol. 23(2001), p.751.

[12] Yong Zhong, Yiyin Shan, Furen Xiao, et al.: Material Letters Vol. 59(2005), p.1780.

[13] Meibao Chen and Rong Wang: Materials for Mechanical Engineering Vol. 28 (2004), p.18 (in Chinese).

[14] Xiulin Zheng, in: Quantitative Theory of Metal Fatigue, Northwest Industrial University press, Xi An(1994), in press. (in Chinese).

[15] Meibao Chen and Yurong Jiang: Advanced Materials Research Vol. 311-313 (2011), p.841.

[16] Meibao Chen and Yurong Jiang: Advanced Materials Research Vol. 284-286 (2011), p.1148.