Trend of Resistance Spot Welding Technology of Al-Si Coated Hot-Stamped Boron Steel for Automobile Body

As environmental regulations have been tightened around the world, domestic and foreign automobile industries are increasing the proportion of hydrogen and electric automotive components using lightweight materials to reduce exhaust gas emissions and improve fuel efficiency. In particular, hot-stamped boron steel is being used as an alternative material for frame weight reduction due to thickness reduction, excellent workability, and good elongation. However, surface coating is essential to prevent surface decarburization phenomena and oxidation scale formation between hot stamping processes of boron steel. The coating layer causes many problems in the weldability such as a narrow weldable current range and deterioration of mechanical properties during resistance welding. Therefore, in this study, we introduce research performed to improve the weldability of Al-Si coated hot-stamped boron steel in terms of the material and process.