Shunting Effect in Resistance Spot Welded Joints of Aluminum Alloys

Document Type : Research Article

Authors

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

Abstract

Shunting effect occurs in RSW when the electrical current passes through previous spot welds. Value of this current depends mostly on distance, number, and size of previous spot welds. This will cause some dimensional and metallurgical changes in welding nugget as well as heat affected zone (HAZ). In this study, shunting effect of RSW is considered in a finite element analysis (FEA) model and the results are compared to experiments performed on aluminum alloy 2219. Weld spacing together with welding current and time are considered to discover the effect of shunting current in the final quality of nugget. A three factor experiment design has been performed to find the significance of factors and interactive effects, as well as FEA model verification. Electrothermal and mechanical interactions are considered in the FEA model. Experimental and numerical solutions have yielded comparable similar results in terms of welding nugget properties. Asymmetry in electrical potential, temperature, and stress distribution and geometry of shunted nugget are predicted and verified directly or indirectly. Intense effect of shunting current on nugget height, asymmetric growth of heat affected zone (HAZ) toward previous welding nugget, as well as concentration of alloying elements along grain boundaries are also discovered.

Keywords

Main Subjects

References

[1] A. Hard, „Preliminary test of spot weld shunting in 24ST Alclad”, Welding Journal, 27(6) (1948) 491-495.
[2] H. Chang, H. Cho, A study on the shunt effect in resistance spot welding, Welding Journal, 69(8) (1990) 308-316.
[3] P. Howe, Spot weld spacing effect on weld button size, in: Sheet Metal Welding Conference VI, Paper C, 1994.
[4] B. Wang, M. Lou, Q. Shen, Y. Li, H. Zhang, „Shunting effect in resistance spot welding steels—part 1: experimental study”, Welding Journal, 92(6) (2013) 182s-189s.
[5] J. Senkara, H. Zhang, Cracking in spot welding aluminum alloy AA5754, WELDING JOURNAL-NEW YORK-, 79(7) (2000) 194-s.
[6] H. Zhang, J. Senkara, X. Wu, Suppressing cracking in resistance welding AA5754 by mechanical means, Journal of manufacturing science and engineering, 124(1) (2002) 79-85.
[7] Y. Li, B. Wang, Q. Shen, M. Lou, H. Zhang, „Shunting effect in resistance spot welding steels—part 2: theoretical analysis”, Welding Journal, 92(8) (2013) 231s-238s.
[8] M. Jafari Vardanjani, A. Araee, J. Senkara, J. Jakubowski, J. Godek, Theoretical analysis of shunting effect in resistance spot welding (RSW) of AA2219, Journal of the Chinese Institute of Engineers, 39(8) (2016) 907-918.
[9] H. Huh, W.J. Kang, Electrothermal analysis of electric resistance spot welding processes by a 3-D finite element method, Journal of Materials Processing Technology, 63(1) (1997) 672-677.
[10] N. Ma, H. Murakawa, Numerical and experimental study on nugget formation in resistance spot welding for three pieces of high strength steel sheets, Journal of Materials Processing Technology, 210(14) (2010) 2045-2052.
[11] C.L. Tsai, W.L. Dai, D.W. Dickinson, Analysis and development of a real-time control methodology in resistance spot welding, SAE transactions, (1991) 158-176.
[12] T. Loulou, P.L. Masson, P. Rogeon, Thermal characterization of resistance spot welding, Numerical Heat Transfer, Part B: Fundamentals, 49(6) (2006) 559-584.
[13] J. Shen, Y. Zhang, X. Lai, P. Wang, Modeling of resistance spot welding of multiple stacks of steel sheets, Materials & Design, 32(2) (2011) 550-560.
[14] H. Nied, The finite element modeling of the resistance spot welding process, Weld. J., 63(4) (1984) 123.
[15] W. Zhang, Design and implementation of software for resistance welding process simulations, 0148-7191, SAE Technical Paper, 2003.
[16] J.H. Kim, Y. Cho, Y.H. Jang, Estimation of the weldability of single-sided resistance spot welding, Journal of Manufacturing Systems, 32(3) (2013) 505-512.
[17] M. Hamedi, H. Eisazadeh, M. Esmailzadeh, Numerical simulation of tensile strength of upset welded joints with experimental verification, Materials & Design (1980-2015), 31(5) (2010) 2296-2304.
[18] X. Sun, P. Dong, Analysis of aluminum resistance spot welding processes using coupled finite element procedures, WELDING JOURNAL-NEW YORK-, 79(8) (2000) 215-S.
[19] Z. Hou, I.-S. Kim, Y. Wang, C. Li, C. Chen, Finite element analysis for the mechanical features of resistance spot welding process, Journal of Materials Processing Technology, 185(1-3) (2007) 160-165.
[20] J. Sessler, V. Weiss, Materials data handbook-aluminum alloy 2219, (1966).
[21] J. Bray, Properties and selection: Nonferrous alloys and special purpose materials, ASM Metals handbook, 92 (1990).
[22] MIL-HDBK-, 5J: Metallic materials and elements for aerospace vehicle structures, in, Department of Defense Washington, DC, 2003.
[23] M. Vogler, S. Sheppard, Electrical contact resistance under high loads and elevated temperatures, surfaces, 9(10) (1993) 11.
[24] M.J. Vardanjani, M. Ghayour, R.M. Homami, Analysis of the vibrational stress relief for reducing the residual stresses caused by machining, Experimental Techniques, 40(2) (2016) 705-713.
[25] W.H. Kearns, Welding handbook, Vol. 4, Metals and their weldability, American Welding Society, 1982, (1982) 582.
[26] M. Specification, MIL-W-6858D,“, Welding, Resistance: Spot and Seam, (1978).
[27] J. Saleem, A. Majid, K. Bertilsson, T. Carlberg, M. Nazar Ul Islam, Nugget formation during resistance spot welding using finite element model, in: World Academy of Science, Engineering and Technology: An International Journal of Science, Engineering and Technology, 2012.
[28] Document No. III-1005-93, Section 6, Procedure for spot welding of uncoated and coated low carbon and high strength steels, International Institute of Welding.
[29] M.J. Vardanjani, A. Araee, J. Senkara, J. Jakubowski, J. Godek, Experimental and numerical analysis of shunting effect in resistance spot welding of Al2219 sheets, Bulletin of the Polish Academy of Sciences Technical Sciences, 64(2) (2016) 425-434.
[30] M.J. Vardanjani, A. Araee, J. Senkara, J. Jakubowski, J. Godek, Experimental and numerical analysis of shunting effect in resistance spot welding of Al2219 sheets, 64(2) (2016) 425.
[31] F.C. Campbell, Elements of Metallurgy and Engineering Alloys, ASM International, 2008.
Amirkabir Journal of Mechanical Engineering
Volume 50, Issue 3
September and October 2018
Pages 561-576

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