Eddy Current Pulsed Thermography for Steel Corrosion Characterization

Abstract

Corrosion has been perceived as a terribly damaging problem for steel. This work introduces eddy current pulsed thermography (ECPT) with fast, contactless, and high-precision detection for steel corrosion characterization. In this process, time-domain features of transient thermal responses (TTRs) are extracted to characterize corrosion on Q235 steel specimen. The effect of peak-value (PV), peak-time (PT), the first derivative peak value (FDPV) and the first derivative peak time (FDPT) is emphasized for describing corrosion characterization and improving the detection precision of the obtained features as detection criterion of corrosion characterization. Experimental investigations have related to verify the availability of the characteristics extracted. New sets of thermal images have been constructed according these time-domain features. Image fusion based on wavelet transform is also applied to obtain an image combines advantages of these time-domain features. It can be conducted that the time-domain features imaging takes care of corrosion characterization visually. Above all, the practical results indicate that it is feasible to employ ECPT method on the nondestructive detection of steel corrosion characterization.