【摘要】 依据有限元建模思想,采用高斯表面热源,同时考虑相变潜热与温度的关系,应用ABAQUS软件建立了Q235钢基体上激光重熔合成Fe-Al涂层的温度场和应力场计算模型,研究了激光功率和扫描速度对温度场和应力场的影响。结果表明,提高激光功率对增大热影响区深度效果不大,反而会形成较大的熔池而使重熔表面粗糙;与激光功率相比,扫描速度对温度场影响较小;涂层与基体合金化区沿着激光扫描方向的拉应力远大于垂直扫描方向的拉应力;结合界面处的残余应力与扫描速度成正比,与激光功率成反比,且扫描速度对残余应力的影响较激光功率显著。实验结果较好地验证了模拟结果,表明所建立的温度场和应力场计算模型是正确和可靠的。更多还原

【Abstract】 The remelting process of aluminum coating on Q235 steel substrate was simulated using the finite element software ABAQUS.A Gaussian surface heat source was selected to emulate the laser beam,and the latent heat of coating and substrate was also considered in FEM model.The effects of laser power and scanning speed on the temperature field and stress field were investigated,respectively.The simulation results indicate that comparing with the laser power,the scanning speed has less impact on the temperature field,inversely,its effect on the stress field is more than that of the laser power.As laser power increasing,the width of molten pool increases rapidly,which results in a rough coating surface while the depth of molten pool has little change.Tensile stress in the coating and substrate alloyed zone along the laser scanning direction is larger than that along perpendicular scanning direction in the remelting process.Residual stress in the coating interface zone is proportional to the scanning speed but inversely proportional to the laser power.These simulation results are verified by subsequent experiments.更多还原