Laser polishing efficiently reduces the surface roughness of die steel, but at the same time, residual tensile stress is induced on the surface, leading to crack initiation and propagation. The present study induces residual compressive stress on the laser-polished surface of Cr12 steel by laser shock peening. The surface residual stress of samples, which underwent different treatments, is measured and compared. The experimental results show that laser shock peening effectively eliminates the residual tensile stress generated by laser polishing. The compressive residual stresses of the laser-polished samples subjected to laser shock peening with 3, 6, and 9 J energies are 114.5, −138.5, and −209.5 MPa, respectively. Moreover, the surface roughness, microhardness, and microstructure evolution of the laser-polished surface with laser shock peening are investigated.

中文翻译：

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激光冲击强化对Cr12钢激光抛光表面性能及组织演变的影响

激光抛光有效地降低了模具钢的表面粗糙度，但同时会在表面产生残余拉应力，导致裂纹萌生和扩展。本研究通过激光冲击强化在 Cr12 钢的激光抛光表面上产生残余压应力。测量并比较了经过不同处理的样品的表面残余应力。实验结果表明，激光冲击强化有效消除了激光抛光产生的残余拉应力。激光抛光样品经 3、6 和 9 J 能量的激光冲击强化后的压缩残余应力分别为 114.5、-138.5 和 -209.5 MPa。此外，表面粗糙度、显微硬度、