选用机械制造业广泛使用的优质合金钢40Cr试件，对其进行高周疲劳试验，研究疲劳试验过程中磁信号的特征值与应力集中位置及应力集中程度的关系，引入李萨如图分析法将磁信号法向、切向分量联合绘制二维检测曲线，探讨李萨如图面积与试件的疲劳损伤状态之间存在的关系。结果表明：利用微分后的梯度值突变特征，可准确确定试件疲劳加载引起的应力集中部位；磁信号在初始加载条件下会出现很大变化，随着疲劳循环次数的增加，磁信号变化缓慢，当试件进入裂纹萌生阶段时，磁信号显著增加；李萨如图面积与试件的疲劳损伤状态之间存在良好的对应关系。结果可望为磁记忆二维检测定量分析提供可靠的试验依据。

High quality alloy steel 40Cr is widely used in mechanical manufacturing industry and is selected for the high-cycle fatigue experiments in the paper. The relationship between the characteristic value of magnetic signals during the process of fatigue testing and the stress concentration position and the degree of stress concentration has been researched. The normal component and the tangential component are together detected. The method of Lissajous figure is used to draw two-dimensional curve, the relationship between area of Lissajous figure and the fatigue damage state of the specimen is discussed. It turns out that the mutation characteristics of differential gradient value can be used to accurately determine the stress concentration area caused by fatigue loading; very big change appears in magnetic signals under the beginning of the loading condition, while with the increase of fatigue cycles, the magnetic signal changes slowly. When the crack propagation stage in the specimen is aroused, magnetic signals increase significantly; and there is a good corresponding relationship between area of Lissajous figure and the fatigue damage state of the specimen. It is expected to provide test analysis basis for the quantitative analysis of two-dimensional detection of magnetic memory effect.