Residual plastic deformation induced in low-carbon steels usually demonstrates anisotropy. Eddy current method is applicable for the residual plastic deformation evaluation. However, it is difficult to efficiently evaluate both the principal strain direction and magnitude of residual plastic deformation with the conventional eddy current method. To solve these limitations, a novel method of oscillatory rotating eddy current (OREC) was developed and successfully applied in characterizing the anisotropy of residual plastic deformation in low-carbon steels. The parameters of eddy current response obtained under different frequencies were extracted to characterize the plastic deformation and then the characterization performances of extracted parameters were compared. The compound voltage signal and real part of the impedance could better characterize the residual plastic deformation than the imaginary part of the impedance. It was found that the angle of the major axis of the selected 8-shaped patterns measured with OREC was a good indicator of the principal strain direction. As the residual plastic deformation was increased, the length of the major axis of the 8-shaped patterns monotonously increased despite its sensitivity to the plastic deformation was frequency-dependent.

低碳钢中引起的残余塑性变形通常表现出各向异性。涡流法适用于残余塑性变形评价。然而，用传统的涡流方法很难有效地评估主应变方向和残余塑性变形的大小。为了解决这些限制，开发了一种新的振荡旋转涡流 (OREC) 方法，并成功应用于表征低碳钢残余塑性变形的各向异性。提取不同频率下得到的涡流响应参数来表征塑性变形，然后比较提取参数的表征性能。复合电压信号和阻抗的实部比阻抗的虚部能更好地表征残余塑性变形。发现用 OREC 测量的所选 8 形图案的主轴角度是主应变方向的良好指标。随着残余塑性变形的增加，尽管其对塑性变形的敏感性与频率相关，但 8 形图案的主轴长度单调增加。