承压类特种设备在石油化工等行业应用广泛,然而,出于防腐等需要,承压设备外常涂有涂层,给检测带来了难度。针对涡流检测技术在带涂层检测中的应用,提出了一种基于双切向涡流的阵列探头,并对其阵列单元的性能和阵列探头的整体结构进行分析和设计。理论分析表明,所提出的阵列单元可消除激励线圈到接收线圈直接耦合信号的影响,同时,该探头能够同时实现对不同长度和不同角度裂纹的定量分析,进而提高裂纹的检测精度。此外,为减小提离效应对检测结果的影响,设计了带有弹簧的阵列探头结构,弹簧始终处于压缩状态,以保证在检测过程中探头的提离最小,该研究可为带涂层设备的检测提供一定技术支持。

Pressure equipment is widely used in petrochemical and other industries. However, the pressure equipment is often coated, which brings difficulty to the detection. An array probe based on double tangential eddy current was proposed in this paper, and the performance of the array unit and the overall structure of the array probe were analyzed and designed. The theoretical analysis showed that the proposed array element can eliminate the influence of the direct coupling signal from the excitation coil to the receiving coil. At the same time, since the crack length was only sensitive to the signal peak value, and the crack angle was only sensitive to the peak position, the probe can realize the quantitative analysis of cracks of different lengths and angles at the same time, thus improving the crack detection accuracy. In addition, in order to reduce the lift-off effect on the detection results, the array probe structure with a spring was designed. The spring was always compressed to ensure the minimum lifting of the probe during the detection process. This study can provide technical support for the detection of coated equipment.