Numerical Study of Overlay Welding Effects on Residual Stresses in Girth Welded Steel Pipes

Document Type : Research Article

Authors

Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran

Abstract

The overlay of the outer surface of a pipe by welding is one of the ways to decrease the residual stress. In this research, a finite element model by considering phase transformation effect is developed in the SYSWELD software for the simulation of circumferential welding process of two API X65 steel pipes. This model is validated using a hole drilling method. Then, the effect of overlay welding created by three types of welding filler on the residual stress is investigated. The results show that the overlay welding created by ER70s filer increases axial and hoop stresses. But ER304 and IN600 fillers cause reduction of hoop residual stresses. The stresses at the covered area are compressed because of the increase in heat input as an effective factor. Also, axial stresses due to these filers at low weld energy are greater than sample stress without a cover. However, the value of this stresses decreases when the weld energy increases. Thus, the proportional stress level can be obtained in the pipe using the overlay with filers of ER304 and IN600 associated with a high heat input and by selecting suitable overlay dimensions.

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References

 
[1] V. Karimnia, Investigating the influence of effective parameters on the residual stresses in circumferentially arc welded thin walled cylinders of aluminum alloy series, Modares Mechanical Engineering, 15(3) (2015) 10.
[2] S. Thomas, Analysis of Low Transformation Temperature Welding (LTTW) consumables distortion control and evolution of residual stresses, PHD Thesis, University of Colorado (2013).
[3] F. Fredette, An Analytical Evaluation of the Effect of Weld Sequencing on Residual Stresses Produced by Full Structural Weld Overlays on Pressurized Water Reactor Primary Cooling Piping, ASME Pressure Vessels and Piping Division Conference, 10 (2009) 6.
[4] R. Liu, Welding residual stress analysis for weld overlay on a BWR feed water nozzle, Nuclear Engineering and Design, 11(2) (2013) 12.
[5] P. Dong, Effects of Repair Weld Length on Residual Stress Distribution, ASME Conference, 124 (2002) 7.
[6] F. Iwamatsu, effect of weld overlay repair on residual stress and crack propagation in a welding pipe, ASME Pressure Vessels and Piping Division Conference, (2007) 5.
[7] H. Yen, L. Chen,1996, Residual Stress Measurement in 304 Stainless Steel Weld Overlay Pipes, Journal of Engineering Materials and Technology, 118 (1996) 5.
[8] J. Sung Kim, Investigation on the effects of geometric variables on the residual stresses and PWSCC growth in the RPV BMI penetration nozzles, Journal of Mechanical Science and Technology, (2015) 11.
[9] Y.L. W. Jiang, B.Y. Wang,, Residual stress reduction in the penetration nozzle weld joint by overlay welding, Journal of Materials and Design, (2015) 15.
[10] T. Zhang, D. Rudland,, Weld-Overlay Analyses – An Investigation of the Effect of Weld Sequencing, ASME Pressure Vessels and Piping Division Conference, (2008) 7.
[11] ESI Group, User Manual, (2012).
[12] SYSWELD, Reference Manual, (2014).
[13] J. Goldak, M. Bibby, A new finite element model for welding heat sources, Metallurgical transactions, 15 (1984) 6.
[14] M. Ivanov M.A., The Metodology of Calculation of Geometric size of the Welds on the Parameters of the Mode of Automatic Arc Welding Under a Layer of Flux, Materials Science and Engineering, 8 (2009) 8.
[15] A. Laursen, Influence of Weld Thermal Cycle on Residual Stress of API 5L X65 and X70 Welded Joint, Canadian Welding Association Conference, (2014) 5.
[16] A. Standard, E837-08 Standard Test Method for Determining Residual Stresses by the Hole-drilling Strain-gage Method, ASMT international West Conshohocken, PA, ed., (2008).
[17] X. Ren, Residual Stresses of X80 Pipe Girth Weld, International Offshore and Polar Engineering Conference, (2012) 10.
[18] C. H.Lee, three dimensional finite element simulation of residual stresses in circumferential welds of steel pipe including pipe diameter effects, Materials Science and Engineering, 7 (2008) 6.
[19] A. Chintapalli, weld overlay size sensitivity on residual stress in a welded pipe, ASME Pressure Vessels and Piping Division Conference, (2008) 6.
Amirkabir Journal of Mechanical Engineering
Volume 50, Issue 3
September and October 2018
Pages 479-488

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