Application Research on Micro-magnetic Testing of Train Wheels Detection

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 depth, 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.