The Experiment Research And Simulation Of Laser Lap Welding Of Galvanized Steel With Adding Cu Powder

Zinc-coated steel is an important commercial material.It is durable, cheap and very useful for combating corrosion. Laser welding technology plays an important role in automobile parts. Laser welding speed is fast, heat affected zone is small, weld microstructure is refining, laser welding deformation is small, generally speaking, mechanical properties of weld seam is stronger than the base metal. In this paper, the relationship between plasma temperature and technological parameter on laser welding of galvanized steel is mainly studied. In addition, experiments of laser lap welding of galvanized steels with the different concentrations of Cu powder are mainly researched. Research contents of the topic are as follows.Firstly, structural stability and elastic properties of CuZn、MgZn2 and NiZn have been determinied from first-principles calculation by using Castep program based on the density functional theory. Mechanical property of solid solutions, that is formed by the combination of different concentrations of Cu and Zn has been studied. Through the simulation of zinc alloy and its compounds, the laser welding of galvanized steel with the Cu powder provides an certain theoretical guidance and prediction.Secondly, through the research of the relationship between plasma temperature and technological parameter on laser welding of galvanized steel, relation curves of laser power, speed of welding, defocused distance, shielding gas flow and plasma temperature are analyzed. It has been shown that technological parameter has a certain effect on plasma temperature. Shielding gas flow has obvious impact on the plasma temperature. It decreases with the increasing of shielding gas flow. However, the influence of speed of welding on plasma temperature is least, whose deviation is 1323K. Changes of plasma temperature can provide certain theoretical guidance for moniting and predicting of laser welding with deep penetration.Finally, the experiments of laser lap welding of galvanized steels with the different concentrations of Cu powder are mainly carried out. The mechanical properties, fracture morphology, component distribution and the main phase of the welded joint are detected. Through processing and analysis of experiment data, the property of welding joint of laser lap welding of galvanized steels with the Cu powder of different concentrations is concluded.