Non-destructive evaluation of weld defect with coating using electromagnetic induction thermography

The weld inspection process under coating is complex and labour-dependent. Therefore, it is of great engineering significance to study weld defect inspection. Based on eddy current pulsed thermography (ECPT) method, this work theoretically analysed the mechanism of weld defect detection undercoating and proposed an inductor suitable for defect detection under weld coating to achieve non-contact, rapid and visual detection results. The simulation model for weld defect detection under coating was constructed, and the effect of coating on weld crack inspection was investigated. However, weld defect test blocks with different coating, thicknesses were verified by experiment, and the thermal characteristics of the circular hole area were analysed. The results demonstrate that the proposed method is effective in weld defect detection, which provides a promising way to extend the application of ECPT to weld defect inspection.