Volume 19, Issue 7 (2019)                   Modares Mechanical Engineering 2019, 19(7): 1797-1804 | Back to browse issues page

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Valaee Tale M, Mazaheri Y, Sheikhi M, Malek Ghaini F, Usefifar G. Numerical and experimental investigation of current and electrode force effects on expulsion in resistance spot welding of galvanized and non-galvanized steel sheets. Modares Mechanical Engineering. 2019; 19 (7) :1797-1804
URL: http://journals.modares.ac.ir/article-15-25608-en.html
1- Materials Department, Engineering Faculty, Bu-Ali Sina University, Hamedan, Iran
2- Materials Department, Engineering Faculty, Bu-Ali Sina University, Hamedan, Iran , sheikhi.mohsen@basu.ac.ir
3- Materials Engineering Department, Materials Engineering Faculty, Tarbiat Modares University, Tehran, Iran
4- SAIPA Corporation, Tehran, Iran
Abstract:   (332 Views)
During the process of Resistance spot welding (RSW), some of the molten metal comes out of the interface of the two sheets, which causes contamination on the body of the cars. This named as expulsion and disrupts the staining process and reduces the safety of the workshop. In this study, by numerical and Experimental investigation, effect of welding current and electrode force on expulsion in RSW of galvanized and non-galvanized steel sheets the prediction of expulsion for both sheets was performed. Experimental results showed that with increasing the welding current, nugget diameter and weld strength increased continuously until expulsion occurrence. The resultant nugget in both types of sheets have almost similar diameter at the similar welding current however in the galvanized sheet, expulsion occurred at a larger nugget diameter. Increasing the electrode force before the occurrence of expulsion increased the nugget diameter, but then reduced the nugget diameter. The results of the investigation were found to be consistent with a modified numerical model. In this model, increase in the nugget diameter increased the force from within the nugget and accelerated the expulsion, while the electrode force was a hindrance to the expulsion. Zinc coated on galvanized steel sheets with low contact resistance and friction coefficient between zinc-zinc metal resulted in a good fit between two sheets during the welding process which according to the numerical model, causes expulsion to occur at a larger nugget diameter for galvanized steel sheets.
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Received: 2018/09/29 | Accepted: 2019/01/19 | Published: 2019/07/1

References
1. 1- Ertek Emre H, Kaçar R. Resistance spot weldability of galvanize coated and uncoated TRIP steels. Metals. 2016;6(12):299. [Link] [DOI:10.3390/met6120299]
2. Pouranvari M. Effect of welding parameters on the peak load and energy absorption of low-carbon steel resistance spot welds. ISRN Mechanical Engineering. 2011;2011:824149. [Link] [DOI:10.5402/2011/824149]
3. Senkara J, Zhang H, Hu SJ. Expulsion prediction in resistance spot welding. Welding Journal. 2004 Apr:123-S-132-S. [Link]
4. Mikno Z, Pilarczyk A, Korzeniowski M, Kustroń P, Ambroziak A. Analysis of resistance welding processes and expulsion of liquid metal from the weld nugget. Archives of Civil and Mechanical Engineering. 2018;18(2):522-531. [Link] [DOI:10.1016/j.acme.2017.08.003]
5. Podržaj P, Polajnar I, Diaci J, Kariž Z. Influence of welding current shape on expulsion and weld strength of resistance spot welds. Science and Technology of Welding and Joining. 2006;11(3):250-254. [Link] [DOI:10.1179/174329306X101391]
6. Kimchi M. Spot weld properties when welding with expulsion - a comparative study. Welding Research Supplement. 1984 Feb:58-s-63-s. [Link]
7. Ma C, Bhole SD, Chen DL, Lee A, Biro E, Boudreau G. Expulsion monitoring in spot welded advanced high strength automotive steels. Science and Technology of Welding and Joining. 2006;11(4):480-487. [Link] [DOI:10.1179/174329306X120895]
8. Hwang IS, Kang MJ, Kim DC. Expulsion reduction in resistance spot welding by controlling of welding current waveform. Procedia Engineering. 2011;10:2775-2781. [Link] [DOI:10.1016/j.proeng.2011.04.461]
9. Chan KR. Weldability and degradation study of coated electrodes for resistance spot welding [Dissertation]. Waterloo: University of Waterloo; 2005. [Link]
10. Sheikhi M, Valaee Tale M, Usefifar GR, Fattah Alhosseini A. Thermal modeling of resistance spot welding and prediction of weld microstructure. Metallurgical and Materials Transactions A. 2017;48(11):5415-5423. [Link] [DOI:10.1007/s11661-017-4314-4]
11. Rao SS, Chhibber R, Arora KS, Shome M. Resistance spot welding of galvannealed high strength interstitial free steel. Journal of Materials Processing Technology. 2017;246:252-261. [Link] [DOI:10.1016/j.jmatprotec.2017.03.027]
12. Prigogine I, Defay R, Everett DH. Chemical thermodynamics. London: Longmans; 1954. [Link]
13. Kou S. Welding metallurgy. New Jersey: John Wiley & Sons; 2003. pp. 431-446. [Link] [DOI:10.1002/0471434027]
14. Lin HC, Hsu CA, Lee CS, Kuo TY, Jeng SL. Effects of zinc layer thickness on resistance spot welding of galvanized mild steel. Journal of Materials Processing Technology. 2018;251:205-213. [Link] [DOI:10.1016/j.jmatprotec.2017.08.035]
15. Gould JE. An examination of nugget development during spot welding, using both experimental and analytical techniques. Welding Research Supplement. 1987 Jan:1-s-11-s..   [Link]

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