Pulsed eddy current thermography for corrosion characterisation

Corrosion characterisation on metal substrates is a major problem in the field of corrosion science and Non-destructive Evaluation (NDE). In this work, the electromagnetic NDE method, Pulsed Eddy Current (PEC) Thermography, has been applied to evaluate the corrosion on the mild steel plates. By analysis of heat induction and heat diffusion, early stage thermal images are proposed to avoid the lateral heat diffusion and to detect the corrosion progression more accurately. Principal Component Analysis (PCA) is used to extract the variation information from the different time period image sequences to improve the imaging quality and to validate the early detection theory. Results show that PEC thermography has potential as a rapid tool for corrosion characterisation.