模具磨损表面激光熔覆修复层的数值模拟技术

Numerical sim ulation technology of laser cladding repair layer on wear surface of die

为解决H13模具钢磨损影响模具使用寿命的问题,利用有限元分析软件对H13模具钢激光熔覆Ni基涂层过程进行了仿真分析。在激光熔覆过程中,经历了快速加热和快速冷却两个热传导过程,其熔覆温度最高可达1551℃,考察了不同涂层厚度对温度场的影响,得出涂层越厚,温度越低;涂层表面的焊接残余应力以拉应力为主,基材表面则以压应力为主。研究了不同涂层厚度对应力场的影响,得出涂层越厚,残余应力越大。经实验验证,数值模拟计算的模具磨损激光修复温度场与实验值接近,实验得到的焊接熔化区截面图与模拟结果基本一致,实际熔化区宽度1.19 mm、深度0.20 mm,模拟计算的熔化区宽度1.21 mm、深度0.21 mm,证明了模具磨损表面激光熔覆修复层模拟结果的正确性和方法的有效性。

In order to solve the problem that the wear of H13 die steel affecting the die service life,the process of laser cladding Ni-based coating on H13 die steel was simulated and analyzed using finite element analysis software.In the laser cladding process,two heat conduction processes,rapid heating and rapid cooling were experienced,and its cladding temperature can reach up to 1551 ℃. At the same time,the influence of different coating thickness on the temperature field was investigated,and the thicker the coating,the lower the temperature. In the laser cladding process,the welding residual stress on the coating surface is mainly tensile stress,and the compressive stress is mainly on the substrate surface. The effect of different coating thickness on the stress field was also studied,and the thicker the coating,the greater the resid ual stress. It is verified by experiments tha t the temperature field of laser repair of die wear calculated by numerical simulation is close to the experimental value,and the cross-sectional view of the welding melting zone obtained by the laser cladding test is basically consistent with the simulation result. The actual melting zone width is 1.19 mm and the depth is 0.20 mm;the simulated melting zone width is 1.21 mm and the depth is0.21 mm. The simulation results of the laser cladding repair layer on the wear surface of the die are proved to be correct and the method is effective.