Challenges and Opportunities of Thermography in Metallurgy

High process control and product quality standards in industry and scientific research demand exact temperature determination for metallurgical systems. In many cases, reliable information can be obtained via thermocouple measurements. Still, this option is unfeasible for technologically advanced processes such as consumable vacuum arc remelting due to technical reasons, for example, high temperatures, aggressive melts, or demand for melt cleanliness. Those circumstances necessitate contactless infrared measurement to ensure accurate and non-invasive results. Determining thermal emissivity, the harsh environment, and the dynamic of liquid surfaces in the process are challenging conditions for infrared thermography in metallurgy. However, in return, it allows measuring online with high resolution in time and space at the surface of a metallurgical process, quantifying the amount of superheating or temperature development over time and to detect phases with different thermal emissivity, like slag on metallic phases. This information can be used to increase simulation accuracy, microstructure prediction, as well as process control and comprehension. The study introduces IR-thermography for metallurgical applications with practical examples and demonstrates its successful implementation in a titanium alloy consumable electrode vacuum arc remelting.