RESISTANCE SPOT-WELDING OF PRECOATED STEEL SHEET - COMPUTATIONAL HEAT-TRANSFER ANALYSIS

The heat-transfer phenomenon during the resistance spot welding of the precoated steel sheet, consisting of a thin organic coating coated on a steel sheet, has been investigated theoretically using a two-dimens ional finite-element heat-transfer model. Material parameters such as the thermal conductivity of the coating and the thickness of the sheet were varied under various welding conditions in order to optimize the welding process. These welding parameters included the contact resist ance at the steel/steel interface, the welding current, and the weldin g time. The effect of these material and welding parameters on the wel dability was demonstrated; the selection criteria for the organic coat ing and accompanying welding conditions were proposed from this study.