The Research On Craft Laser Welding Of Ordinary Steels And Zinc Coated High Strength Steels

With the rapid development of technology of the laser welding in recent years, more and more automobile manufacturers have already adopted the advanced welding method. However, the technology of laser tailor welded blanks can connect two or many steel plates, which are coped with different surface, different kinds of steel and various thickness into a semifinished material through the laser welding method, from which the manufacturers adopt it directly for ramming to the vehicle body components and parts.The essential feature of the deep penetration laser welding is that it exists keyhole effects. The main parameters of influencing welding quality are the power of laser, the speed of welding, the position of focal and the gas of protection. According to the theory and the experimentation in this paper, the author analyzes the craft research of the CO2 laser tailor welded blanks of different thick vehicle body, which makes use of ordinary steel and zinc coated high strength steel.To begin with, the author analyzes the performance and the feature of the automobile body ramming to use steel plates. Its materials need not only the ramming process form perfect, but also satisfy the rigidity, intensity and the protection ability of the components and so on. The ordinary steel in this research exists the high shape performance, the good surface quality and the good welding performance. The zinc coated high strength steel can not only anti-erode quite well but also has high intensity and takes good shape.What's more, the author introduces the superiority of the laser tailor welded blanks. and its present situation of the production as well as the research. And has carried on the theoretic analysis to the laser welding mechanism and the influence factor. Meanwhile, the author analyzes the performance of the laser welding between the zinc coated high strength steel and ordinary code rolled steel. The welding ability is good of ordinary steel.But the zinc coated high strength steel has a bit worse performance because of its stronger carbon equivalent as well as the influence of the zinc against the wefding quality.Last,but not the least,the author makes the CO₂ laser tailor welded blanks experiment toward thee kinds of different thick and zinc coated high strength steel,the golden microstructure analysis,the tersile strength experiment and the erichsen experiment.the resuls of all kinds of analysis revealed that it can obtain satisfied welding quality and the junction is higher than the ordinary cold rolled steel.