Review of Resistance Spot Welding Sheets: Processes and Failure Mode

The engineering parts joining by the spot welding require acceptable properties to survive the loading conditions XE "temperature". Several studies show that the welding variables have an effect on the properties of spot nugget XE "nugget" and on the future cracking. This review summarizes the resistance spot welding process (RSW). It introduces the basic spot welding principles, experiments XE"experiments" , limitation and defects XE "defects". The new concepts and awareness were presented. The results from the series of scientific works and literature are discussed. The metal’s weldability, XE "spotweldability" strength, XE"strength" and fracture are the main topics in several structural analysis. The welding variables effect on the mechanical properties and performance XE "mechanicalproperties" of the structures is the key analysis. In general, the increasing of the heat input by adjusting the current, time, and pressure producing higher weld area in turn enhance the toughness. However, by increasing the weld area, the defects and cracking tend to appear. Hence, a desired weld size with the mechanical properties is required. The nugget fracture mode is changing from plug or button tearing to shear failure mode depending on the weld properties. The crack grows either from the internal defects or around the nugget.