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

The application of magnetic field in welding process has been proved to be effective in improving the mechanical properties of welded joints and is regarded as a practicable auxiliary welding method. Although the theoretical research on magnetic field‐assisted welding is quite abundant, there is still a long way to go before a stable industrial application is achieved. Therefore, to clarify magnetic field and compare its roles in various welding techniques, this work carefully examines the use of magnetic field in recent welding techniques such as laser welding, laser‐melt inert gas hybrid welding, gas metal arc welding, tungsten inert gas welding, and resistance spot welding. Based on previous experiments and simulation research results, the effects of the Lorentz force on the arc, molten pool, and dendrite solidification during welding as well as the microstructure and mechanical properties of welded joints are discussed. The purpose of this work is to give a superficial introduction to the magnetic field‐assisted welding method in recent years, hoping to improve the welding practitioners’ understanding of the magnetic‐assisted welding method and provide a reference for researchers who use different welding methods. The external magnetic field exerts Lorentz forces on the arc and the molten pool in the weld. Different directions of the magnetic field produce different directions of Lorentz forces in the arc and molten pool. The Lorentz force generated by the magnetic field can be used to improve welding defects, increase welding efficiency, refine weld grain, and enhance mechanical properties.