Browse > Article
http://dx.doi.org/10.3795/KSME-A.2013.37.3.405

Prediction of Steady-State Stresses within Heat Affected Zone Due to Creep Mismatch in Welded Straight Pipes  

Han, Jae-Jun (Dept. of Mechanical Engineering, Korea Univ.)
Kim, Sang-Hyun (Dept. of Mechanical Engineering, Korea Univ.)
Chung, Jin-Taek (Dept. of Mechanical Engineering, Korea Univ.)
Kim, Yun-Jae (Dept. of Mechanical Engineering, Korea Univ.)
Publication Information
Transactions of the Korean Society of Mechanical Engineers A / v.37, no.3, 2013 , pp. 405-412 More about this Journal
Abstract
This paper reports the steady-state stresses within the heat affected zone (HAZ) of a welded straight pipe subject to creep. The creep constants and exponent are varied systematically to see the effect of various mismatches in creep properties on the steady-state creep stresses, via detailed two-dimensional finite element (FE) creep analyses. The weldments consist of the base metal and weld metal with the HAZ, which are characterized using the idealized power creep laws with the same creep exponent. The internal pressure and axial loading are considered to see the effect of the loading mode. To quantify the creep stresses, a creep mismatch factor is introduced as a function of the creep constants and exponent. It is concluded that the ratio of the section-averaged stresses for a mismatched case to those for an evenmatched case are linearly dependent on the mismatch factor. The results are compared with the FE results, including the Type IV region, as well as the R5 procedure.
Keywords
Creep Mismatch; Finite Element Analysis; Steady-State Stress; Heat Affected Zone; Stress Redistribution;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Webster, G. A. and Ainsworth, R. A., 1994, High Temperature Component Life Assessment, Chapman & Hall, London, pp. 10-49.
2 Parker, J. D., 1995, "Creep Behaviour of Low Alloy Steel Weldments," International Journal of Pressure Vessels and Piping, Vol. 63, No.1, pp. 55-62.   DOI   ScienceOn
3 Roberts, B. W., Ellis, F. V. and Viswanathan, R., 1985, "Utility Survey and Inspection for Life Assessment of Elevated Temperature Headers," Proc. of the American Power Conference, Chicago, IL, pp. 289-301.
4 Viswanathan, R. and Dooley, R. B., 1986, "Creep Life Assessment Techniques for Fossil Power Plant Boiler Pressure Parts," Proc. of International Conference on Creep, Tokyo, pp. 349-359.
5 Hyde, T. H., Sun, W. and Williams, J. A., 2003, "Creep Analysis of Pressurized Circumferential Pipe Weldments - A Review," Journal of Strain Analysis for Engineering Design, Vol. 38, No. 1, pp. 1-30.   DOI   ScienceOn
6 R5, 2003, Assessment Procedure for the High Temperature Response of Structures, Issue 3, British Energy Generation Ltd, UK.
7 Goldthorpe, M. R., 2008, "Effect of Weld Mismatch on Uncracked Stresses, Reference Stresses and C* Estimates for Cracks in CMV HAZ Materials," British Energy Generation report, E/REP/BDBB/0046/GEN/ 04, British Energy Generation Limited, UK.
8 Law, M. and Payten, W., 1997, "Weld Performance under Creep Using Finite Element Modelling," International Journal of Pressure Vessels and Piping, Vol. 72, No. 1, pp. 45-49.   DOI   ScienceOn
9 Lee, K.-H., Kim, Y.-J., Yoon, K.-B., Nikbin, K. and Dean D., 2010, "Quantification of Stress Redistribution due to Mismatch in Creep Properties in Welded Branch Pipes," Fatigue & Fracture of Engineering Materials & Structures, Vol. 33, No. 4, pp. 238-251.   DOI   ScienceOn
10 Han, J.-J., Lee, K.-H., Kim, Y.-J., Nikbin, K. and Dean D., 2011, "Effects of Geometry and Combined Loading on Steady-State Creep Stresses in Welded Branches," International Journal of Pressure Vessels and Piping, Vol. 88, No. 10, pp. 395-402.   DOI   ScienceOn
11 R6, 2010, Assessment of the Integrity of Structures Containing Defects, Revision 4, British Energy Generation Ltd, UK.
12 Baker, A. J., 2000, "Stress Redistribution Factors for 21/4Cr1Mo Weld Metal in 1/2Cr1/2Mo1/4V Weldments," British Energy Generation report, EPD/GEN/REP/0514/99, British Energy Generation Limited, UK.
13 Oh, C.-K., Kim, Y.-J., Park, J.-M., Kim, J.-S. and Jin T.-E., 2007, "Effect of Structural Geometry and Crack Location on Crack Driving Forces for Cracks in Welds," Engineering Fracture Mechanics, Vol. 74, No. 6, pp. 912-931.   DOI   ScienceOn
14 Abaqus 6.11, Analysis User's Manual, 2011, Dassault Systemes Simulia Corp., Providence, RI.
15 Laham, S. A., 1999, "Large Bore Branch Test Creep Analysis," British Energy Generation report, EPD/GEN/REP/0371/98, British Energy Generation Limited, UK.
16 Dean, D. and Kiff, S. J., 2000, "Creep Deformation Data and Weld Redistribution Factors for 1/2Cr1/2Mo1/4V Type IV Zones," British Energy Generation report, EPD/GEN/REP/0443/99, British Energy Generation Limited, UK.
17 Easterling, K., 1992, Introduction to the Physical Metallurgy of Welding, Butterworth-Heinemann, London.
18 Antaki, G., 2005, Fitness-for-Service and Integrity of Piping, Vessels and Tanks, McGraw-Hill, New York.
19 Walters, D. J. and Cockcroft, R. D. M., 1972, "A Stress Analysis and Failure Criteria for High Temperature Butt Welds," Proc. of International Institute of Welding Colloquium on Creep Behaviour of Welds in Boilers, Pressure Vessels and Piping, Toronto.
20 Walters, D. J., 1976, "The Stress Analysis of Cylindrical Butt Welds Under Creep Conditions," CEGB Note, RD/B/N3716,Central Electricity Generating Board, UK.