钢制叶片激光冲击强化与渗铝的组合应用

Laser shock processing and aluminizing compound technology used on steel blade

采用扫描电子显微镜(SEM),X射线衍射(XRD)等手段研究了激光冲击强化(LSP)对钢制叶片渗铝层的影响,结果表明渗铝后进行激光冲击强化会对渗铝层造成破环,而在渗铝之前进行激光冲击强化则能提高渗层质量.从残余应力和显微组织变化两方面分析了渗铝高温作用对不锈钢材料激光冲击强化效果的影响,激光冲击强化产生的残余压应力在510℃渗铝温度环境下保温150min仍有-295MPa稳定存在,晶粒细化组织也没有明显长大,激光冲击不锈钢材料的残余应力和微观组织具有良好的热稳定性.振动疲劳对比试验结果验证了"LSP+渗铝"组合工艺对不锈钢材料的强化效果,在660MPa应力水平下,采用该组合工艺试片的疲劳寿命为3.98×106,为原渗铝试片疲劳寿命的14倍左右.

Scanning electron microscopy （SEM）, X-ray diffraction （XRD） and other techniques were used to detect the influence of laser shock processing （LSP） on aluminizing layer, which is infiltrated into the stainless steel blade for antisepticising. The results show that the aluminizing layer will be destroyed when LSP is implemented after aluminizing. And the quality of aluminizing layer will be improved while LSP is implemented before aluminizing. The influence on the LSP by the high temperature in the course of aluminizing was studied through residual stress test and metallographic analysis. After 150 minutes in the condition of aluminizing temperature 510℃, the residual compressive stress in the LSP zone was still -295MPa and the refined grain did not grow up remarkably. The residual compressive stress and grain refinement layer induced by LSP had good thermo stability. Finally, the vibration fatigue performance of different states stainless steels was tested. When the maximum stress is 660MPa, the fatigue life of ＂LSP before aluminizing＂ is about 3.98×10^6 , which is about fourteen times than that of aluminizing.