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Variability of Fatigue Crack Initiation Life in Flux Cored Arc Welded API 2W Gr.50 Steel Joints

  • Sohn, Hye-Jeong (Department of Mechanical Design Engineering, Pukyong National University) ;
  • Kim, Seon-Jin (Department of Mechanical and Automotive Engineering, Pukyong National University)
  • Received : 2012.06.08
  • Accepted : 2012.08.25
  • Published : 2012.08.31

Abstract

Flux Cored Arc Welding (FCAW) is a common practice to join thick plates such as the structural members of large scale offshore structures and very large container ships. The objective of this study was to investigate the mechanical properties and variability of the fatigue crack initiation life in the flux cored arc welded API 2W Gr.50 steel joints typically applied to offshore structures with a focus on the effect of the materials in fatigue crack growth life from the notch root of a compact tension specimen. Offshore structural steel (API 2W Gr.50) plates (60-mm thick) were used to fabricate multi-path flux core arc welded butt welded joints to clearly consider fatigue fractures at the weld zone from the notch. Fatigue tests were performed under a constant amplitude cyclic loading of R = 0.4. The mean fatigue crack initiation life of the HAZ specimen was the highest among the base metal (BM), weld metal (WM), and heat affected zone (HAZ). In addition, the coefficient of variation was the highest in the WMl specimen. The variability of the short fatigue crack growth rates from the notch tips in the WM and HAZ specimens was higher than in BM.

Keywords

References

  1. http://www.chapelsteel.com/api-2h-grade-50.html
  2. Kazuyuki, S. and Takeshi, S. (2003). "Welding Consumables for Offshore Structures," Technical Paper of Kobe Steel, Vol. 53, No. 2, pp. 85-89.
  3. Lee, H.K., Kim, K.S. and Kim, C.M. (2000). "Fracture Resistance of a Steel Weld Joint under Fatigue Loading," Engineering Fracture Mechanics, Vol. 66, 403-419. https://doi.org/10.1016/S0013-7944(00)00017-5
  4. Riahi, H., Bressoltte, Ph. and Chateauneuf, A. (2010). "Random Fatigue Crack Growth in Mixed Mode by Stochastic Collocation Method," Engineering Fracture Mechanics, Vol. 77, pp. 3292-3309. https://doi.org/10.1016/j.engfracmech.2010.07.015
  5. Min, L., Qing, S. and Yang, Q.X. (1996). "Large Sample Size Experimental Investigation on the Statistical Nature of Fatigue Crack Initiation and Growth," Int. J. Fatigue, Vol. 18, No. 2, pp. 87-94. https://doi.org/10.1016/0142-1123(95)00068-2
  6. Virkler, D.A., Hillberry, B.M. and Goal, P.K. (1979). "The Statistical Nature of Fatigue Crack Propagation," J. Engineering Materials and Technology, ASME, Vol. 101, pp. 148-153. https://doi.org/10.1115/1.3443666
  7. Ortiz, K, and Kiremidjian, A.S. (1986). "Time Series Analysis of Fatigue Crack Growth Rate Data," Engineering Fracture Mechanics, Vol. 25, No. 4, pp. 657-668.
  8. Itagaki, H., Ishizuka, D. and Huang, P. (1993). "Experimental Estimation of the Probability Distribution of Fatigue Crack Growth Lives," Probabilistic Engineering Mechanics, Vol. 8, No. 1, pp. 25-34. https://doi.org/10.1016/0266-8920(93)90027-S
  9. Wu, W.F. and Ni, C.C. (2007). "Statistical Aspects of Some Fatigue Crack Growth Data," Engineering Fracture Mechanics, Vol. 74, pp. 2951-2963.
  10. Lennart, B. and Ringsberg, J.W. (2009), "Assessment of Uncertainties in Life Prediction of Fatigue Crack Initiation and Propagation in Welded Rails," International Journal of Fatigue, Vol. 31, pp. 1413-1421. https://doi.org/10.1016/j.ijfatigue.2009.03.024
  11. Goto, M. (1998). "Statistical Investigation of the Effect of Laboratory Air on Fatigue Behavior of a Carbon Steel," Fatigue & Fracture Engineering Materials & Structures, Vol. 21, pp. 705-715. https://doi.org/10.1046/j.1460-2695.1998.00047.x
  12. Costa, J.D., Brancot, C.M. and Radon, J.C. (1997). "Short Fatigue Crack Growth Behavior in Al 5083 Alloy," Int. J. Fatigue, Vol. 19, No. 2, pp. 161-168.
  13. Moltubakk, T., Thaulow, C. and Zhang, Z. (1999). "Application of Local Approach to Inhomogeneous Welds. Influence of Crack Position and Strength Mismatch," Engineering Fracture Mechanics, Vol. 62, pp. 445-462. https://doi.org/10.1016/S0013-7944(98)00108-8
  14. Hou, C.Y. and Charng, J.J.(1997). "Models for the Estimation of Weldment Fatigue Crack Initiation Life," Int. J. Fatigue, Vol. 19, No. 7, pp. 537-541. https://doi.org/10.1016/S0142-1123(97)00072-8