针对冷轧轧辊的表面微细裂纹检测问题,提出了一种双层排线磁化的交流漏磁检测方法,利用双层柔性排线对轧辊工 作表面进行仿形磁化,采用高精度隧穿磁阻(TMR)阵列作为检测元件,使其具备大曲率表面微米级裂纹的检测能力;并通过调 控双层排线的激励电流抵消切向背景磁场,进一步提高激励电流的同时,避免 TMR 超量程饱和问题;将磁场的切向分量用以表 征缺陷,使其能在单一扫查方向下表征多向裂纹。 基于以上分析,建立了双层排线与轧辊的三维有限元仿真模型,通过仿真研 究轧辊半径、缺陷角度和深度对交流漏磁信号的影响。 最后搭建了相应验证实验平台,实验结果表明该探头能有效磁化大曲率 表面并可检出与区分多向裂纹,可检测出 15 μm 深的微细裂纹。
To address the problem of micro-cracks detection on the surface of cold-rolled rolls, this article proposes an alternating current magnetic flux leakage detection method excited by double-layer flexible parallel cables, which is used to profile the working surface of the rolls, and uses the high-precision tunnel magnetoresistance ( TMR) sensor array as the detection sensor. It has the ability to detect micro-cracks on large curvature surfaces. Meanwhile, by adjusting the excitation current of the double-layer PCs to offset the tangential component of the background magnetic field, the excitation current is increased further and the TMR overrange saturation problem is avoided. The tangential component of the magnetic field is used to characterize defects, enabling it to characterize multidirectional cracks in a single scanning direction. Based on the analysis above, this article establishes a three-dimensional finite element simulation model of double-layer PCs and roll, and studies the influence of roll radius, defect angles and depth on AC MFL signal through simulation. Finally, a corresponding verification experimental platform is established. Experiment shows that the probe can effectively magnetize the surface with large curvature, detect and distinguish multidirectional cracks, and detect micro-cracks at a depth of 15 μm.
姜 春,汪圣涵,唐 健,康宜华.基于双层排线探头的轧辊表面微裂纹检测方法[J].仪器仪表学报,2023,(6):188-196复制