对K403镍基合金涡轮叶片进行激光冲击强化(LSP),利用高温高低周复合疲劳试验验证其强化效果。试验结果表明:冲击后裂纹源区附近平坦区较冲击前变大,在快速扩展(FCG)区,激光冲击强化后疲劳条纹间距减小,有大量二次裂纹产生。且强化后在材料表层会引发晶粒细化以及高残余压应力,但在550℃/150min保温下,残余应力部分发生松弛,但是表层细化结构有很好的热稳定性。相比冲击前样件,激光冲击强化后涡轮叶片疲劳寿命提高了140%。热松弛后的残余压应力和表面晶粒细化是镍基合金疲劳寿命提高的主要原因。 The K403 nickel-based alloy turbine blades were laser shock-enhanced (LSP), and the strengthening effect was verified by high-temperature high-low cycle combined fatigue test. The experimental results show that the flat area near the crack source area becomes larger than that before impact, and in the FCG area, the fatigue stripe spacing decreases after laser shock and there are many secondary cracks. After strengthening, grain refinement and high residual compressive stress are induced on the surface of the material. However, the residual stress relaxes at 550 ℃ for 150min, but the surface thinned structure has good thermal stability. Compared to the pre-impact specimen, the fatigue life of the turbine blade increased by 140% after laser shock. Residual compressive stress and surface grain refinement after thermal relaxation are the main reasons for the increase of fatigue life of Ni-based alloys.