Aperiodic Thermal Wave Imaging Approach for Non-Destructive Testing and Evaluation of Steel Material: A Numerical Study

Abstract

InfraRed Thermography has proved to be an indispensable approach for non-destructive testing and evaluation of solids, due to its inherent merits such as remote, whole-field, qualitative and quantitative inspection capabilities. Present work explores the possibility of detecting sub-surface inclusions in modeled mild steel sample using this technique. Most of the commonly used industrial components are generally made up of mild steel materials including construction beams, chimneys, sliding and rod type gates etc. Safety and demand for quality of in-service products require rigorous testing and reliable monitoring methodology to avoid catastrophic failures. Non-destructive characterization plays an essential role to avoid sudden failures and huge economic losses through the thorough frequent inspection of these materials. This work emphasize on capabilities of linear frequency modulated thermal wave imaging for characterization of steel specimen having inclusions as defects. Finite element based analysis has been proposed to model a mild steel sample by introducing six different materials as slag inclusions. Further, widely used post processing techniques (based on time and frequency domain) have been adopted on the simulated results and the comparisons have been made among them for visualizing the inclusions hidden inside the test sample.