Modeling of Induction Infrared Thermography for Non-Destructive Evaluation of Alloy Sensitization
Abstract
This project investigates the efficacy of using induction infrared thermography (IIRT) as a non-destructive method for detecting welding-induced sensitization in stainless steels, using a combined experimental and computational approach. A series of laboratory experiment have been conducted to demonstrate this method, using a radio frequency function generator, an induction wand, a FLIR SC8203infrared camera, and the 440C steel as a representative material. Traditional metallography techniques and scanning electron microscopy (SEM) have been employed to identify the location of any sensitized regions and characterize the corresponding microstructure. For welded 440C steel plates, the IIRT experimental results reveal a distinguishable heat signature, with higher temperature observed within the sensitized regions. Next, a computational study has been conducted to simulate the IIRT experiment and investigate the underlying physics. A three-dimensional thermo-electro-magnetic model has been adopted, which combines Fourier's law of heat conduction and Maxwell's equations for predicting the electromagnetic field caused by a sinusoidal excitation current owing through the induction coil. We solve the system of governing equations using the commercial solver COMSOL Multiphysics. To numerically investigate the possible causes of the disproportionate heating within the sensitized regions, the values of electrical resistivity and magnetic permeability therein are varied. The simulated results indicate that the heat signature observed in the laboratory experiment may result from the increase of both electrical resistivity and magnetic permeability in the HAZ.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 03, 2020
- Accession Number
- AD1114060
Entities
People
- Emily Guzas
- Kevin G. Wang
- Matthew Roberts
Organizations
- Virginia Tech