304不锈钢激光焊接工艺及数值模拟

采用激光自熔焊接技术对304不锈钢进行平板焊接试验,并通过对比分析微观组织和力学性能结果,得出最佳工艺参数为:P=2.6 kW、v=30 mm/s、Δf=+2 mm。通过金相组织表征、X射线荧光衍射和电子背散射衍射等分析方法得出焊接接头的焊缝组织由奥氏体和铁素体组成。依据最佳工艺参数选用大型通用有限元模拟软件ABAQUS,并采用高斯面热源和高斯旋转体组合热源对激光焊接过程进行模拟。将模拟获得的焊缝截面形貌和试验获得的焊缝截面形貌进行对比,并根据对比结果优化模拟模型。仿真结果表明,在移动热源的前端位置,等温线较密集,温度梯度较大,而移动热源后方,等温线较为稀疏,温度梯度减小。

Laser welding process and numerical simulation of 304 stainless steel

In this paper,the plate welding experiment of 304 stainless steel was carried out by using laser self-fusion welding technology,and the test results were analyzed from the microstructure and mechanical properties.Optimum process parameters as follow,laser power 2.6 kW,welding speed 1.8 m/min,defocus amount+2 mm.The composition of austenite and ferrite in welded joint was obtained by metallographic structure characterization,X-ray fluorescence diffraction and electron back scattering diffraction.According to the best process parameters,the large-scale general finite element simulation software ABAQUS is selected,and the combined heat source of Gaussian surface heat source and Gaussian rotating body is used to simulate the laser welding process.The cross-sectional morphology of the weld obtained by simulation and the cross-sectional morphology of the weld obtained by the experiment are compared,and the simulation model is optimized according to the comparison result.The simulation results show that in the front of the moving heat source,the concentration of isotherms is large,and the temperature gradient is large,while behind the moving heat source,the isotherms are sparse and the temperature gradient is also reduced.