球铁曲轴激光冲击强化实验研究

Experimental research of laser shock strengthening nodular iron crankshaft

为了研究激光冲击强化对球铁性能的影响，采用钕玻璃脉冲激光（波长为1054nm，脉冲宽度为23ns）对球墨铸铁（简称球铁）曲轴试样表面进行冲击强化处理，并对其显微硬度、残余应力和疲劳强度进行实验测试与分析。结果表明，在激光功率密度为10．6Gw／cm^2的强脉冲激光作用下，冲击区的显微硬度明显增加，表层材料的显微硬度比基体约提高65％～75％；冲击区表面存在残余压应力，数值高达-400MPa，使用寿命提高150％。实验结果表明，激光冲击球铁曲轴的强化效果明显。

In order to study the effect of Laser Shock Processing （LSP）on the properties of nodular iron, nodular iron crankshaft was processed with Nd：glass laser with the wavelength of 1054 nm and pulse width of 23 ns, and its micro-hardness, residual stress and the fatigue intension were examined and analyzed. The experimental results show that with laser power density of 10. 6 GW/cm^2 ,Laser Shock Processing（LSP） improves hardness and residual stress of nodular iron crankshaft significantly, surface micro-hardness increases by up to 65% - 75% and the compressive residual stress on the surface of laser shocked area reaches up to -400 MPa, using life increases about 150%. The experiment results show that the effect of laser shock evidently strengthens the nodular iron crankshaft.