为探索裂纹宽度与磁记忆信号之间的关系，以45CrNiMoVA钢为试验材料，对具有不同预置切口宽度的试件进行静载拉伸试验，并采用磁记忆检测仪检测试件表面的磁记忆信号，研究了不同外加载荷下试件表面磁记忆信号的变化，并对各预置切口位置处磁记忆信号梯度变化进行分析。结果表明： 随着外加载荷的增加，试件表面磁记忆信号不断增强，矩形槽位置处磁记忆信号梯度变化加剧，磁记忆信号梯度值随外加载荷的增加而单调增大；外加载荷值相同时，磁记忆信号梯度随裂纹宽度先减小后增大，而非简单的线性关系。

To explore the relationship between magnetic memory signals and crack width of ferromagnetic materials, static tension tests of specimens made of 45CrNiMoVA steel with precut slots of different width were performed, and magnetic memory signals of the specimens were measured by a magnetic memory apparatus. Both the variation of magnetic memory signals under different applied loads and the gradient value of magnetic signals of each slot were analyzed. The results of the study clearly showed that the magnetic memory signals of the specimen increased with increasing of applied load, and the gradients of magnetic memory signals of the precut slots increased monotonically. A nonlinear relationship was presented between the gradient of magnetic memory signals and the width of precut slot under the identical condition of applied load. The gradients first decreased and then increased with the crack width increasing.