Welding zinc coated steels: New joint design and strategy with scanner technology

The existing problems of weld defects in welding zinc coated steels in a overlap situation are present in the automotive industry. The root cause is the different melting temperature of zinc and steel. Zinc vapourises already at 900C versus steel melts at 1500C. The result, if not taking care of the outgassing are pinholes and craters in the weld seam. Extensive research has been taken on with highspeed cameras to evaluate the root cause. Based on extensive research a new joint design, called k-design has been developed and successful tested. The new design guarantees welds without defects caused by zinc, watertight seams and allows twice the welding speed compared to traditional overlap welds. The presentation will also report on a new strategy to create joints between to zinc coated steel sheets with the use of newest scanner welding technology.