Review: magnetically assisted resistance spot welding

Abstract

Currently, the use of advanced high strength steels (AHSSs) is the most cost effective means of reducing vehicle body weight and maintaining structural integrity at the same time. However, AHSSs present a big challenge to the traditional resistance spot welding (RSW) widely applied in automotive industries because the rapid heating and cooling procedures during RSW produce hardened weld microstructures, which lower the ductility and fatigue properties of welded joints and raise the probability of interfacial failure under external loads. Changing process parameters or post-weld heat treatment may reduce the weld brittleness, but those traditional quality control methods also increase energy consumption and prolong cycle time. In recent years, a magnetically assisted RSW (MA-RSW) method was proposed, in which an externally applied magnetic field would interact with the conduction current to produce a Lorentz force that would affect weld nugget formation. This paper is a review of an experimental MA-RSW platform, the mode of the external magnetic field and the mechanism that controls nugget shape, weld microstructures and joint performance. The advantages of the MA-RSW method in improving the weldability of AHSSs are given, a recent application of the MA-RSW process to light metals is described and the outlook for the MA-RSW process is presented.

Impact of electromagnetic stirring upon weld quality of Al/Ti dissimilar materials resistance spot welding

“…It can be seen that the weld nugget produced under the action of EMS (EMS weld) becomes larger and thinner than the traditional resistance spot weld. This is consistent with the results from earlier studies [11][12][13] showing that the EMS drives the molten metal in the nugget to flow clockwise and generates a centrifugal movement, which will promote the growth of the nugget in a radial direction.…”

“…Shen et al have found that EMS could refine the grain structure, increase the weld nugget diameter, reduce the risk of shrinkage cavities, and improve the mechanical properties of the joint in RSW of advanced high-strength steel DP590 [8] and DP780 [9,10]. Li et al have studied the effect of EMS upon the nugget formation of DP980 steel and they found that, under the action of EMS, the nugget symmetry improved and the macrocrystallization direction in the fusion became less obvious [11]. Li et al have investigated the effect of EMS upon resistance spot welds of 5052 aluminum alloy, and suggested that the effect of EMS was more sensitive to the change of welding time and was insensitive to the change of electrode force [12].…”

Recent developments in the design, development, and analysis of the influence of external magnetic-field on gas-metal arc welding of non-ferrous alloys: review on optimization of arc-structure to enhance the morphology, and mechanical properties of welded joints for automotive applications

“…Li et al. [ 22 ] observed the consequence of the EMF in many welding processes for weld arc stability and weld pool behaviors. Li et al.…”

Effects of Magnetic Fields in Arc Welding, Laser Welding, and Resistance Spot Welding: A Review

“…To further improve the welding quality of the joint, in recent years, numerous scholars have developed various welding‐assisted methods. For instance, magnetic field‐assisted, [ 1 ] ultrasonic‐assisted, [ 2,3 ] induction heating‐assisted, [ 4,5 ] laser‐assisted, [ 6,7 ] vibration‐assisted, [ 8,9 ] and arc‐assisted laser welding [ 10 ] (LW) are applied. The magnetic field‐assisted welding method, in particular, has garnered a lot of attention and interest because of its simple components, low cost, and effective weld formation.…”