本文探讨用大功率CO_2激光处理25CrMnSi钢板CCT试件的裂纹端部,对比激光处理的试件与未处理试件的结果表明,激光处理后能提高ΔK_(th),提高疲劳寿命2倍以上,能降低da/(dN)。通过对试件的微观组织分析和微观硬度测量,找出了激光热处理高强度钢板的初步激光热处理规范,并对试验结果进行了统计分析,得到了疲劳裂纹扩展循环数N与激光处理参数的近似关系式。 This paper discusses the use of high-power CO_2 laser treatment of 25CrMnSi steel CCT specimens crack end, the comparison of laser-treated and untreated specimens showed that after laser treatment can improve the ΔK_ (th), increase the fatigue life of more than 2 times, Can reduce da / (dN). Through the microstructure analysis and the micro-hardness measurement of the test piece, the preliminary laser heat treatment specification of the laser heat-treated high-strength steel plate was found, and the experimental results were statistically analyzed. The fatigue crack growth cycle number N and the laser processing parameter were obtained Relationship.