In recent years, laser peening technique has been used for the purpose of improving the fatigue strength of metal materials. However, the compressive residual stress field created by laser peening has characteristic differences in the stress value and the thickness of the stress field layer compared to conventional technologies. We conducted experiments to clarify the peening mechanism of metals when irradiated with nanosecond laser pulses. Austenite stainless steel was irradiated with a laser pulse of 2.5 ns, and the compressive residual stress inside the recovered sample was examined by x-ray diffraction. Using the dislocation density model, we analyzed the experimental results and showed that the residual stress field due to the nanosecond laser can be explained by the local stress generated by the shock wave.

近年来，为了改善金属材料的疲劳强度，使用了激光喷丸技术。然而，与传统技术相比，通过激光喷丸产生的压缩残余应力场在应力值和应力场层的厚度方面具有特征差异。我们进行了实验，以阐明用纳秒激光脉冲照射时金属的喷丸机理。用2.5ns的激光脉冲照射奥氏体不锈钢，并通过X射线衍射检查回收的样品内部的压缩残余应力。使用位错密度模型，我们对实验结果进行了分析，结果表明，纳秒激光产生的残余应力场可以用冲击波产生的局部应力来解释。