【摘要】 本文探讨用大功率CO₂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。更多还原

【Abstract】 The end-cleavage of 25CrMnSi steel CCT samples treated by a high-power CW CO2 laser are investigated for improving the miorostructure of the material, changing the stress distribution of the end-cleavage and enhancing the performances of the fatigue failure resistance of the material. It has been shown that △Kth of the materials is increased, the fatiguelifetime is prolonged by over two times and is reduced after laser treatment. The approximate empiric formula is obtained relating the cycle number N of the fatigue crack spread to the laser treatment parameters by means of statistic analysis of the experimental data.更多还原