Study On The Process Of Laser-Plasma Arc Hybrid Welding With Filling Powder

Welding technology is an indispensable advanced manufacturing technology for high-quality and high-efficiency production in modern industry,with a wide range of applications.With the development of science and technology,the application of high-energy beam welding methods in various fields has gradually expanded.In order to solve the problems of single heat source welding,the research focus of researchers has shifted from single heat source welding to hybrid welding.As a widely used austenitic stainless steel,304 stainless steel is widely used in the welding field due to its superior welding performance.Therefore,is it of great importance to study the joint morphology,microstructure and mechanical property after welding.This article takes 304 stainless steel as the research object,proposes the "process of laser-plasma arc hybrid welding with filling powder ",and conducts experimental research and numerical simulation verification on the proposed process.The laser-plasma arc hybrid welding with filling powder process experiment was carried out with 3mm 304 stainless steel,and the welded joints under different process parameters were obtained and compared with the joints of a single heat source.The effects of several main process parameters(laser power,plasma arc current,laser defocus distance)on the macro and micro morphology of the weld and the mechanical properties of the joint were analyzed.The simplified three-dimensional heat source model and finite element analysis model of the laser-plasma arc welding process are established.The transient simulation of the temperature-flow coupling field was carried out.The temperature field and the flow field were analyzed separately to explain the interrelationship between the macroscopic morphology and the microstructure.The results show that: for 304 stainless steel plate welding,the laser-plasma arc hybrid welding with filling powder welding process is an effective welding method.This welding method has better gap adaptability and heat source alignment adaptability than single heat source welding process.Due to the interaction of the heat sources,the rigidity and penetration of the plasma arc are improved and a larger penetration depth can be obtained.The process parameters have a great influence on the macro and micro morphology of the welded joint.The change of process parameters affects the change of heat input and the flow state of the molten pool.The joint efficiency is between 94% and108% and the elongation is less than the base material.