Device and method for testing steel defect based on internal and external magnetic perturbation

A device for testing a steel defect based on internal and external magnetic perturbation, comprising:

• a magnetizer comprising a magnetization source and two magnet yokes, wherein, the two magnet yokes are located at two sides of the magnetization source, the magnetizer is arranged on a surface of a sample, and the magnetizer is configured to generate two types of typical magnetic field regions applied to testing based on internal and external magnetic perturbation;
• a double-row magnetic sensor probe, configured to collect internal and external magnetic perturbation data, wherein a first row of magnetic sensors of the double-row magnetic sensor probe is an internal magnetic perturbation sensor array, a second row of magnetic sensors of the double-row magnetic sensor probe is an external magnetic perturbation sensor array, the internal magnetic perturbation sensor array is located below the magnetization source and not in contact with the magnetization source, and the external magnetic perturbation sensor array is located at any of two sides of the internal magnetic perturbation sensor array;
• a master controller, configured to perform pre-processing on the internal and external magnetic perturbation data, and store the pre-processed data;
• scanner wheels, configured to generate a sampling trigger pulse during scanning to enable the master controller to receive the internal and external magnetic perturbation data from the probe;
• and
• a host computer, configured to analyze the pre-processed data uploaded by the master controller to obtain a defect quantitative result.