圆孔缺陷直径与应力集中对金属磁记忆信号的影响

制备了含有圆孔缺陷的试样,通过磁学分析和磁记忆检测,研究了圆孔缺陷直径和应力集中对磁记忆检测结果的影响。结果表明,磁场强度梯度平均值K_(ave)和最大值K_(max)、磁场强度梯度曲线围成的面积S(K)、金属极限状态系数m_(max)随着圆孔缺陷直径的增大而增大;缺陷位置因磁导率变化而引起磁记忆信号变化;缺陷位置磁场强度梯度曲线相邻两个峰值的间距W_(P-P)随着圆孔缺陷直径的增加而增大。同一缺陷的磁场强度最大值H_(max)、磁场强度曲线围成的面积S(H)随着外加载荷的增加逐渐增大。

Influence of hole diameter and stress concentration on metal magnetic memory signal

In order to studythe effects of the diameter of the hole and the stress concentration on the magnetic memory signal, the specimen containing hole defects was prepared, and the magnetic memory experiments on specimen under different applied loads were performed and analyzed. The results show that the averageKave and maximumKmax of magnetic field intensity gradient, the areaS(K) enclosed by the curve of magnetic field intensity gradient, and metal limit state coefficientmmax increase with the increasing of defect diameter. The magnetic memory signal changes due to the change of the magnetic permeability of the defect; the distance between the two peaks of the intensity gradient of the same defect increases with the increasing of the hole diameter. Also, the maximumHmax of magnetic field strength and areaS(H) surrounded by magnetic field intensity curve of the same defect increase with the increasing of applied loads.