Monday  |  Salon 9  |  01:50 PM–02:10 PM

#15546, Thermographic Quantification of Hidden Corrosion for Informed Maintenance Strategies

Almost all metals are susceptible to deterioration via corrosion. If undetected this can lead to premature part failure costing millions of dollars and potentially loss of life. Non-destructive evaluation can be used to inspect parts in-situ during their life and particularly pulsed thermography has shown great potential. Pulsed thermography uses an infrared camera to monitor the surface of a sample while a short heat pulse is applied and subsequently decays. Due to the difference in thermal properties between defects, such as corrosion, and sound areas, defects can be detected. However, inspection quality is currently highly dependent on operators and often only high-risk areas are inspected. To reduce the need for these highly skilled operators and increase the inspected area, an algorithm was developed to autonomously detect and quantify the early onset of corrosion under coatings. Mild steel samples were coated with jet black anticorrosion paint before being exposed to three corrosive environments: an accelerated weathering chamber, a saline solution and outside in Hamilton, New Zealand. The algorithm succeeded to detect, quantify and track the progression of corrosion under the coating with a 3% accuracy compared to its true extent. The calculated percentage of defective area allows inspectors to make an informed decision about the state of the sample and decide on further monitoring or remediation measures.

Larissa Kopf   The University of Waikato
Rachael Tighe   The University of Waikato