无缝钢轨静态拉伸的漏磁效应试验研究

Study on Magnetic Flux Leakage Effect of Seamless Rail Under Static Tension Test

基于金属磁记忆检测方法,用实验室静态拉伸模拟无缝钢轨的缺陷的产生,利用EMS-2000金属磁记忆诊断仪对PD3无缝钢轨进行漏磁效应研究,获得PD3无缝钢轨在不同载荷下表面漏磁场强度法向分量Hp(y)和其梯度值K的分布情况。研究发现,随着载荷的增加,试样测量线上磁场强度及其梯度值呈规律性的变化。Hp(y)过零点与梯度K的极值点能够较好地表征样品应力集中位置的特征,Hp(y)幅值和梯度K的变化能反映样品应力集中程度。该试验表明金属磁记忆检测技术可以有效地应用于无缝钢轨应力集中位置和程度的判断。

Based on the metal magnetic memory testing, using static tension to simulate the formation of defects of the seamless rail, a metal magnetic memory diagnostic instrument （EMS-2000） is applied to study the magnetic flux leakage effect of PD3 seamless rail. The normal component of magnetic strength Hp（y） and the gradient value K on the surface of PD3 seamless rail are tested at different loads under static tension condition. The results show that the magnetic field strength and the gradient value of the specimen change regularly as the load increases. The zero-crossing point of Hp（y） and the peak value point of K are corresponding to the stress concentration area, and the variation of the amplitude of Hp（y） and K is related to the degree of stress concentration. The experiments show that the position and level of the stress concentration of seamless rail can be effectively tested by magnetic memory method.