轧辊表面激光强化应力场的分布规律

Distribution Rules of Stress Field Induced by Laser Strengthening on the Roll Surface

针对轧辊激光强化过程中的应力场求解困难的问题,根据该应力场与辊面瞬变温度场的耦合作用,将温度场计算结果作为初始条件,建立了应力场仿真的有限元模型.综合考虑了材料的热弹塑性能,获得了轧辊激光强化过程中不同位置、不同时刻的应力分布曲线.结果表明,垂直扫描方向上的应力变化最剧烈,在不考虑相变应力的前提下,扫描后该向应力由压应力转变为拉应力状态,从而影响裂纹生成.此外,主应力方向基本与有限元模型的几何坐标相对应,只是随着应力数值的交错变化而发生改变.

Due to the difficulty in calculating the stress distribution induced by laser strengthening on the roll surface, the numerical simulation technology is adopted in this article. Based on the coupling effect between laser-induced stress field and sharply-changing temperature distribution, the temperature simulation results can be regarded as the initial conditions to establish FEM model for stress simulation. Considering the thermo elastc^plastic performance, the stress distribution curves at different locations and different time can be obtained. The simulation results indicate that the stress perpendicular to the scanning direction is the prominent component. Furthermore, the stress will change from compressive stresses to tensile ones without considering the phase transformation after laser treatment, and which can influence the crack generation. Moreover, the directions of principle stresses are basically correspondent to the coordinate directions, but they will alternate with the change of stress magnitudes.