激光喷丸强化对电化学充氢316L奥氏体不锈钢振动疲劳性能的影响

研究了激光喷丸强化对电化学充氢316L奥氏体不锈钢振动疲劳性能的影响.测试分析了不同激光功率密度喷丸316L不锈钢充氢试样的残余应力、显微硬度和微观组织结构,并对比研究其振动疲劳寿命和断口形貌.结果 显示,激光喷丸诱导材料表层位错密度增加,并有效细化晶粒,抑制了氢原子的入侵,同时复杂晶界和高密度位错增殖结构阻碍了氢原子...

Effect of Laser Peening on Vibration Fatigue Performance of Electrochemically Hydrogen-charged 316L Austenitic Stainless Steel

The effect of laser peening on vibration fatigue performance of electrochemically hydrogenated 316L austenitic stainless steel was studied. The residual stress, microhardness and microstructure of laser peened specimens with different power densities followed by hydrogen charging were tested and analyzed, and the vibration fatigue life and fracture morphology of the corresponding specimens were compared and studied. The results show that laser peening induces an increase in dislocation density on the surface of material and effectively refine the grains, which inhibits the invasion of the hydrogen atom. At the same time, the complex grain boundary and high density dislocation multiplication structure hinder the aggregation and diffusion of hydrogen atoms, reduce the degree of the martensitic transformation of 316L austenitic stainless steel, which helps to suppress micro-crack initiation. On the other hand, the high residual compressive stress induced by laser peening not only inhibits hydrogen penetration, but also increases the fatigue crack growth threshold and slows down the crack growth rate. Vibration fatigue test results show that the fatigue life of laser peened specimens with different power densities followed by hydrogen charging has been significantly improved, and the maximum amplitude can be up to 79.36%. The fracture morphology analysis further proves that laser peening can effectively reduce the fatigue crack growth rate of hydrogen-charged specimens, increase the fracture toughness of the material, and then improve the vibration fatigue properties of materials.