低合金高强度钢激光冲击波强化试验研究

Experimental Study on High-strength Low Alloy Steel by Laser Shock Processing

对低合金高强度钢40CrNi2Si2MoVA在激光冲击波作用下引入的残余压应力进行了研究。首先利用激光冲击波强化工艺对试件分别进行1次、2次和3次重复冲击试验,然后在此基础上再进行10%搭接率的重复冲击试验。通过对各试件表面残余压应力和硬度的测量与对比,归纳了激光冲击波强化残余压应力与硬度的特征。最后对40CrNi2Si2MoVA强化影响层深度进行了理论预测与实验对比。

The compressive residual stress of high-strength low alloy 40CrNi2Si2MoVA is researched with laser shock process- ing. Firstly the 40CrNi2Si2MoVA samples are enhanced and strengthen by usage of laser shock processing with one shock, two overlapping shocks and three overlapping shocks. Secondly the two overlapping shocks are implemented by comparison experi- ment with optimal overlapping rate 10%. The surface residual compressive stress and hardness on the testing samples are measured and compared, the characteristics of residual compressive stress and hardness are discussed based on the experiment result. Finally, the depth of enhanced and hardening layer on section face of 40CrNi2Si2MoVA samples by laser shock is con- sidered by usage of hardness gradient under the comparison of theory and experiment.