激光冲击强化对异种不锈钢焊接接头振动疲劳性能影响的分析

Analysis of Effect of Laser Shot Peening on Vibration Fatigue Performance of Dissimilar Stainless Steel Welded Joints

研究了1Cr14Ni3W2VB/1Cr18Ni9Ti异种不锈钢手工钨极氩弧焊对接接头的激光冲击强化技术,对比分析了不同的激光冲击强化参数对于试验件显微硬度、残余应力、显微组织和振动疲劳寿命的影响。结果表明,激光冲击强化后,试样表面压应力明显增加,最大可达259 MPa,且距表面约1 mm深度内均为残余压应力。距试样表面1 mm深度内均为残余压应力。随着激光冲击强化能量增加,激光冲击强化试样的残余压应力呈增大趋势。特别是8 J激光冲击强化后,焊缝热影响区的晶粒细化效果明显,显微硬度显著增加,试样振动疲劳寿命与未激光冲击强化试样相比增加了2.57倍。将该技术应用到某型航空发动机压力传感器壳体的修理上,保障了该压力传感器的使用可靠性。

The laser shot peening technique of 1Cr14Ni3W2VB/1Cr18Ni9Ti dissimilar stainless steel argon arc welding butt joint was studied,and the influence of different laser shot peening parameters on the microhardness,residual stress,microstructure and vibration fatigue life was compared and analyzed.The results show that after laser shot peening,the surface compression stress of the samples increases significantly,reaching maximum of 259 MPa,and the stress is compression stress within about 1 mm depth from the surface.With the increase of laser shot peening energy,the residual compressive stress of the laser shot peening sample increases.After 8 J of laser shot peening,the grains of the heat affected zone of the joint are obviously refined,and the microhardness increases obviously,the vibration fatigue life of the sample increases by 2.57 times compared with that of the sample before laser shot peening.The technology is successfully applied to the repair of an aero-engine pressure sensor,which ensures the reliability of the pressure sensor.