中文摘要：

针对火车轮内部缺陷,提出了一种基于地磁场环境下的无损检测方法。首先理论分析微磁检测应用于火车轮轮对内部缺陷的可行性,然后根据火车轮外观尺寸设计火车轮微磁检测系统,最后通过检测预制人工孔洞缺陷的火车轮试块完成微磁检测的试验部分。研究采用阈值法处理磁梯度检测信号,数据分析结果验证微磁检测对火车轮内部缺陷检测的可行性。试验结果表明：试件中孔洞缺陷直径一定时,埋藏深度越深,缺陷引起的磁感应强度相对变化量越小,而当孔洞缺陷埋深一定时,孔洞缺陷直径越大,缺陷引起的磁感应强度相对变化量也同样会越小,但磁场的异常区域越大;采用阈值法可有效识别缺陷,并实现缺陷微磁检测的可视化。

英文摘要：

In this paper , a non-destructive testing method based on geomagnetic field was proposed for internal defects in the train wheels. Firstly , the feasibility of micro-magnetic testing on the internal defects of train wheels was analyzed theoretically. Then, this paper designed the train wheels micro-magnetic testing system, according to the shape and size of the train wheels. Finally, the experimental part of the micro-magnetic testing was completed through testing the test blocks which were processed artificial holes. This article used the threshold method to deal with magnetic gradient detection signal. The data analysis results verified the feasibility of micro-magnetic testing on the internal defects detection of train wheels. The experiment results showed that： When the hole diameter was constant, the deeper the buried d e p th , the smaller the relative change in the magnetic induction intensity caused by the defects, and when the depth of the hole was certain , the larger the hole diameter, the relative change in the magnetic induction intensity caused by the defect was also smaller, but the abnormal area of the magnetic field was larger; The threshold method could effectively identify the defects and realized the visualization of the micro-magnetic testing.