基于PECT的金属保护层重合处干扰研究

对实际工业现场的有包覆层设备开展脉冲涡流检测(PECT),发现包覆层的外部金属保护层搭接重合处对检测结果造成干扰;利用试验手段,分别在金属保护层采用非铁磁性材质的铝皮及铁磁性材质的白铁皮条件下进行干扰试验;研究结果表明,当金属保护层为铝皮时,各段保护层搭接重合处引起的干扰信号可通过直接观察检测结果的晚期时窗信号直接进行滤除,不影响缺陷的检出;而当金属保护层为白铁皮时,由各段保护层搭接重合处引起的干扰信号无法滤除,故当缺陷位于重合处时则无法检测.

Research on Interference at Overlap of Metal Protective Layer Based on PECT

Pulse eddy current testing(PECT)is carried out on the insulated equipment in the actual industrial field,and it is found that the overlapped overlap of the outer metal protective layer of the insulation will interfere with the detection results.By experimental method,respectively in the metal protective layer using the ferromagnetic material of galvanized sheet and the non-ferromagnetic material of aluminum skin for interference detection.The research results show that when the metal protective layer for aluminum skin,The interference signal caused by overlapping of the protective layer of each section can be filtered directly by the late window signal observed,and it does not affect the testing of defects.When the metal protective layer is galvanized sheet,the interference signal caused by the overlap of each protective layer cannot be filtered,so the defect cannot be tested when it's located at the overlap.