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论文类型：期刊论文

发表时间：2018-08-15

发表刊物：IEEE SENSORS JOURNAL

收录刊物：SCIE

卷号：18

期号：16

页面范围：6540-6546

ISSN号：1530-437X

关键字：Low frequency; saturation magnetization; internal defect detection

摘要：A ferromagnetic material equipment internal defect detection system based on low-frequency (20-50 Hz) electromagnetic technique was proposed. Direct current magnetization was used to make the ferromagnetic material sample (20# steel for instance) be in a saturation magnetization state to decrease its permeability, which is beneficial for increasing the skin depth of the sample and strengthening the signal of the magnetic flux leakage. A low-frequency alternating current source was used to excite the spatial alternating electromagnetic field and a Hall sensor was used to collect the signal of the spatial magnetic field. Experimental results showed that the 6-mm buried depth internal defect with the sensitivity of 0.05 mm can be detected in the 12-mm thick 20# steel plate or pipeline, which is almost 1.5 times higher than that of the current similar sensors.