目的 研究功率密度对激光冲击E690高强钢表面Ostwald熟化现象的影响。方法 根据理论分析激光冲击金属材料与产生调幅分解的内在联系，提出因激光冲击强化产生 Ostwald熟化现象所需要的条件。使用场发式透射电镜(TEM)获取激光冲击E690高强钢试样表面微观组织结构和选区电子衍射花样，观测不同功率密度的TEM形貌相中晶粒尺寸的变化特征，以及Ostwald熟化现象验证。结果 通过TEM形貌像可以看出，E690高强钢基材是由铁素体层与渗碳体层交替重叠组成的珠光体形貌，在激光冲击强化作用下，发生了晶粒细化，薄层渗碳体逐渐消失，电子衍射花样逐渐呈圆环状变化。当激光功率密度上升至4.07 GW/cm²时，持续细化的材料发生粗化，出现调幅分解组织，选区电子衍射花样中出现卫星斑，E690高强钢表面发生了Ostwald熟化现象。当激光功率密度达到5.09 GW/cm²，E690高强钢表层产生了纳米晶。结论 较弱和较强的功率密度都不能使脱溶物到达发生Ostwald熟化机制的临界半径，Ostwald熟化现象与纳米晶相邻出现。

Laser shock peening is a surface modification technology with great potential and application prospect. Given the extremely short loading time (ns) and extremely large load (GPa) of laser shock peening, samples undergoing laser shock treatment exhibited spinodal decomposition without nucleation, which induced Ostwald ripening phenomenon. Compared with the Ostwald ripening phenomenon caused by heat treatment, the impact phase transition caused by laser shock peening is more complex. Therefore, researching the Ostwald ripening phenomenon induced by laser shock peening has certain theoretical significance for laser shock strengthening technology.