• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.42-49
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• 2005

In general, multi-lap spot weld joints are frequently present in automobile. Most research, however, has been focused on the single-lap spot weld joints until now. In this paper, tensile-shear strength tests are performed to examine the weldability of 3-lap spot joint welded by using the high strength steel sheet and the zinc coated steel sheet. The indentation depth and nugget diameter are used to propose the optimum welding conditions. The weldability is affected by the welding current and welding time for 3-lap spot joint. Meanwhile the expulsions is round to decrease with the increase of electrode force. The optimum welding conditions are presented for 3-lap spot joints of high strength steel sheet and zinc coated steel sheet.