Numerical Simulation Of Laser Welding In 1mm Stainless Steel Plate And Study On Joint Performance

The welding process parameters, such as laser power, welding speed, defocusing etc, these parameters are undoubtedly quality stability of welding process and the joint plays a crucial role. Because of lmm thick 304 stainless steel sheet with thin thickness, its binding of small, large welding deformation, the pure theoretical research is difficult to solve the problems in production, a large number of tests will increase the cost. Therefore, the research methods contains experimental and numerical simulation. First through the experiments to study the morphology of the weld process parameters, this paper can summarize the influence law of penetration width. Then according to the analysis of mechanical properties of welded specimens this paper does research on the relationship between process parameters and weld strength and structure change. Finally, through the establishment of mathematical model of laser welding, the calculation of welding temperature field, strain, stress field in laser welding of thin plate, this paper summarizes the law of the variation with process parameters. For its application in the practice of production, realize the automation of welding process and lay a solid foundation, has the very important theoretical and practical significance.Firstly, through the nonlinear finite element software SYSWELD on laser welding of thin plate finite element model, this paper sets up the finite element numerical simulation of the boundary condition according to the actual working conditions. Then the finite element numerical simulation analysis on the sheet laser with different laser power and welding speed under different welding. The results can be obtained in laser welding power and welding deformation and residual stress is positively correlated, welding speed and the welding deformation and residual stress is negatively related. Welding speed, welding deformation and residual variation of laser power the more significant force effect. Then, this paper analyzes the influence of pre-tension method of welding stress and deformation. By applying the pre-tensile stress in the plate at both ends, then this paper get the numerical simulation of laser welding. By analyzing the simulation result, the applied pre-tension stress deformation can be reduced 32.88%, the residual stress can be reduced 20.65%, the longitudinal residual stress decreased the most obvious effect, can reduce 29.72%.This paper carries out a large number of welding experiment by changing the process parameters of different process parameters, weld joint morphology is good, the penetration width and depth to width ratio of the situation changes. General rules obtains preliminary effects of process parameters on the size of weld joint. Then based on the theory of orthogonal experiments, this paper is screened and tensile test of specimens, the influence law of process parameters on tensile strength.This paper gets the best welding process parameters for 2KW 3m/min power, welding speed, defocusing amount Omm, protective gas as argon gas, gas flow rate of 40L/min. The maximum tensile strength of weld joint can meet the strength of the base material 83%. Then this paper studies metallographic analysis and hardness test specimen tensile strength for the best, further in-depth understanding of the microstructure of weld joint and weld zone and heat affected zone hardness change.