The Research Of Laser-arc Hybrid Welding Cold-rolled Precison Stainless Steel

Series 400 stainless steel is excellent in oxidation resistance, corrosion resistance,and low prices relatively to the series 300 stainless steel, with an increasing proportion of application in modern industry. But, this kind of steel hardly ever has the phase change in the process of heating and cooling, which makes the grain near the weld easy to grow and embrittle when using the common argon arc welding and laser welding. The welding joint performance is poor, so this defect greatly limits its application. Laser-arc hybrid welding is a new type of welding technology, with the advantages of high efficiency, high quality and energy conservation and so on. This paper solves the problem of welding before cold rolling ferritic stainless steel plate rolling through the laser- TIG hybrid heat source welding method.Laser-TIG hybrid welding is a new welding technology, which inherits the advantages of both laser welding and TIG welding, and also makes up the defects and limitations of single welding method, which can effectively solve the problem of the welding of ferritic stainless steel. The paper uses 430 cold-rolled ferrite stainless steel as the base material, and systematically analyzes the influence of laser-TIG hybrid welding parameters(laser power, arc current, welding speed, etc.) on sheet metal forming and the weld penetration, etc, which provides the necessary theoretical basis and welding parameters for optimizing the welding parameters and improves the welding quality. Study on the microstructure and mechanical properties of the hybrid welded joints, and the influence of comparison in adding the welding wire or not. The results show that the seam of the laser-TIG hybrid welding is similarly characterized by "goblet" shape. When the weld grain is hot, the affected zone is relatively small,and there is a certain columnar crystal. The results of joint mechanical property test results show that the highest hardness of the hybrid welded joints appears in the vicinity of the weld seam and the heat affected zone, which is 300.2HV. The ultimate tensile strength of the joint is 443.33 MPa, which reaches 89.65% of the base metal.The bending strength of the joint reaches 83.53% of the parent material, and the number of repeated bending reached to 6 times, which is consistent with the practical application of the standard. The results show that the method of laser-TIG hybrid welding method is feasible for welding the 430 ferritic stainless steel.