Creep Continuum Damage Analysis for a Pressurized Thick Wall Circumferentially Welded CrMoV Steel Pipe at 640°C

Abstract:

The failure assessment for thick wall CrMoV steel pipes circumferentially welded at 640°C was studied using the Finite Element (FE) method under close-ended, open-ended and axial compression conditions, respectively. The life and position of failure, redistribution of stress on the welds and damage variations were obtained using damage modeling. Since there is a distinct mismatch of mechanical properties in parent material, weld material and heat affect zone, variations of damage with time, stress redistribution and failure life in each zone are different. The FEM results show that the weakness of the welds is the heat-affected zone (HAZ) where the hoop stresses increase sharply in the tertiary stage of creep. The maximum of damage of the welds lies on the inner surface of in the weld zone when failure occurs. The information is useful for assessing the performance of practical service welds in power plants pipe work.

• Periodical: Advanced Materials Research (Volumes 97-101)
• Pages: 922-927
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.97-101.922
• Online since: March 2010
• Authors: Kun Rong Jia, Zhu Feng Yue
• Keywords: Creep, Damage, Finite Element, Welds

References

[1] Coleman, M. C. and Miller, D. A., Inspection, Assessment and Repair Strategies for Type IV Cracking in Power Plant Components, AWS/EPPI Conf., Orlando, Florida, (1994), pp.5-15.

[2] Hall, F. R. and Hayhurst, D. R: Proc. R. Soc. London, A443 (1991), pp.383-403.

[3] Perrin, I. J. and Hayhurst, D. R: J. Strain Analysis, Vol. 31 (1996), pp.299-314.

[4] Hyde, T. H., Sun, W., Becker, A. A. and Williams, J. A: J. Strain Analysis, Vol. 32 (1997), pp.273-285.

[5] Hyde TH, Williams J. A, Becker AA, Sun W: Mater High Temperatures, Vol. 16 (1999), pp.117-129.

[6] Hyde TH, Sun W, Williams J.A. Hayhurst, D. R., On the Role of Creep Damage in Structural Mechanics, Engineering Approaches to High Temperature Design, edited by B. Wilshire and D. R. Owen, Pineridge Press, Swansea (1983), Chapter 3, pp.85-176.

[7] Hyde TH, Williams JA, Becker AA, Sun W. A review of the finite element analysis of repaired welds under creep conditions, Int: Proceedings of the 3rd international HIDA conference on advances in defect assessment in high temperature plant. Lisbon, Portugal; September 2002. pp.29-44.

[8] Perrin I. J, Hayhurst D. R: Int J Pre Piping, Vol. 68 (1996), pp.299-309.

[9] Hyde TH, Sun W, Becker AA: Int. J. Mech. Sci. Vol. 38 (1995), pp.1089-1102.

[10] Hyde TH, Sun W: JSME Int. J . Solid Mech Mater Eng Ser A 2000; 43: pp.408-414.

[11] Hyde TH, Sun W. Creep of waisted notched cross-weld specimens. In: Proceeding of 7th international conference on creep and fracture of engineering materials and structures. Irvine(CA): August 1997. pp.759-68.

[12] ABAQUS/Standard user's manual version 6. 6 Hibitt, Karlsson, Sorensen, Inc.