Pulsed eddy current infrared thermal imaging detection system and method for steel rail cracks

Abstract

The invention discloses a pulsed eddy current infrared thermal imaging detection system and method for steel rail cracks. The system comprises an excitation device, an induction heating device, an infrared thermal imager and a PC, wherein the induction heating device is used for generating a pulse current signal; the pulse current signal is exerted to a tested part through the excitation device; eddy current is induced from the surface of the tested part and a thermal effect is generated, so that the surface temperature distribution changes; the infrared thermal imager is used for recording the surface temperature change process of the tested part and transmitting to the PC to process and analyze. The pulsed eddy current infrared thermal imaging detection system is characterized by also comprising a synchronous trigger control circuit, which is used for synchronously controlling the excitation and recording time of the induction heating device and the infrared thermal imager, so that the heating and cooling processes after complete induction of the tested part are accurately recorded; and the condition that the PC obtains accurate data to analyze and treat is ensured. The pulsed eddy current infrared thermal imaging detection system is high in detection efficiency and high in image resolution ratio; excitation of an excitation source and the infrared thermal imager can be synchronously carried out; and the detection result is not affected by human factors.

Description

technical field [0001] The invention belongs to the technical field of non-destructive testing, and in particular relates to a pulsed eddy current infrared thermal imaging detection system and a method for rail cracks. Background technique [0002] Railway transportation is the main transportation mode of land transportation in the world today. As an important part of railway, the quality inspection of steel rail is very important. During the operation of high-speed trains, when the train speed reaches a certain value, the degree of rail wear decreases, and the contact surface between the wheel tread and the inner side of the top surface of the rail is the main stress-bearing part, and the final defect form is mainly rolling contact fatigue damage, which is the most important. A structural defect. When the train wheel repeatedly acts on the surface of the rail, the internal structure of the material will change due to the cyclic effect of tension and compression stress, and ...

AI Technical Summary

Problems solved by technology

The detection system has the following defects: 1. The excitation source used is a high-frequency excitation source. Although it has a high excitation frequency, its excitation power is insufficient and the detection efficiency is low; 2. The acquisition frequency of the infrared thermal imager used Only 50Hz, the image resolution is not large enough to reflect some details of the crack in detail; 3. The excitation source and the excitation of the infrared thermal imaging camera are performed manually separately, and the detection results are easily affected by human factors

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