基于激光冲击的W6Mo5Cr4V2高速钢刀具材料疲劳性能研究

Fatigue Performance of W6Mo5Cr4V2 High Speed Steel Cutter Materials Based on Laser Shock

以W6Mo5Cr4V2(M2)高速钢刀具材料为试样,研究激光冲击对M2材料疲劳性能的影响。对M2试样进行激光冲击处理、金相组织观察、残余应力测量及疲劳性能检测等试验,分析激光冲击对试样表层材料微观组织、残余应力和疲劳性能的作用机理。结果表明,激光冲击后M2试样表层微观组织晶粒细化,晶界增多.形成位错与李晶等晶格缺陷;激光冲击区产生一定深度的残余压应力层,横截面上的残余压应力由表及里逐渐减小,表面残余压应力值最大,距表面一定距离范围内,残余压应力值基本稳定;激光冲击前后,试样的平均疲劳寿命有显著提高,不同的激光冲击工艺参数对试样的疲劳性能产生不同的影响。激光冲击处理使M2高速钢表层材料得到强化,疲劳性能有效改善。

Taking W6Mo5Cr4V2 (M2) high speed steel cutter material as sample,the effect of laser shock on fatigue performance of M2 material is studied. Experiments of laser shock processing,metallographic observation, residual stress measurement and fatigue performance test on M2 samples are conducted. The mechanism of laser shock on surface microstructure ,residual stress and fatigue performance is analyzed. The results show that after laser shock . the surface microstructure grains of M2 samples are refined and the grain boundaries in crease,forming lattice imperfecti on such as dislocation and twin crystal. A certain depth of residual compressive stress layer is caused within shocked area. The residual compressive stress on cross section is decreased from surface to center. The surface residual compressive stress is maximum. In a certain distance from surface, the residual compressive stress is stable. Before and after laser shock, the average fatigue life of sample is significantly improved. Different laser shock process parameters have differert effects on the fatigue performance of the sample. By laser shock,the surface material of the M2 high speed steel is strengthened and its fatigue performance is improved.