风机塔筒焊缝缺陷漏磁与磁扰动检测性能对比

Comparasion of the detection performance of magnetic flux leakage and magnetic field disturbance in weld defect of turbine tower

风机塔筒焊缝缺陷种类多样,不仅对塔筒的结构完整性构成重大威胁,对焊接区的无损检测也提出了相当大的挑战。采用漏磁与磁扰动检测方法对风机塔筒焊缝区域进行检测并对比其检测性能,为利用两种方法综合检测塔筒焊缝缺陷提供依据。首先,研制了适于焊缝缺陷检测的漏磁与磁扰动阵列传感器,制备了4种类型的缺陷试样并构建了检测试验平台;其次,试验获得了不同缺陷的漏磁与磁扰动多通道阵列扫查结果,并采用插值成像的方法对缺陷进行了二维成像;最后,利用检测结果对漏磁与磁扰动检测的性能进行了对比分析。结果表明,漏磁检测在小宽度裂纹检测和圆孔深度表征方面优于磁扰动检测,磁扰动则对小角度裂纹和小尺寸圆孔缺陷的检出性能更好。

The turbine tower exhibits a variety of weld defects,which not only pose a significant threat to its structural integrity but also present a substantial challenge for non-destructive testing of the welding zone.This study investigated and compared the detection methods and characteristics of magnetic flux leakage(MFL)and magnetic field disturbance(MFD)in the weld area of the turbine tower through experimental analysis,providing a foundation for comprehensive detection of weld defects using both approaches.Firstly,the MFL and MFD array sensors specifically designed for weld defect detection were developed.Additionally,four types of defect samples and constructed a comprehensive test platform were prepared.Secondly,Scanning results were obtained using the MFL and magnetic disturbance multi-channel arrays under various defect conditions.These defects were then imaged using an interpolation imaging method.Finally,by comparing and analyzing the detection results,it was found that MFL detection outperformed MFD in terms of detecting small-width cracks and characterizing hole depths.On the other hand,MFD was more effective in detecting small-angle cracks and smaller-sized hole defects.