The use of infrared thermography to detect thermal instability during solidification of peritectic steels

Infrared thermography has been carried out on a range of commercial steel grades (including peritectic grades) during solidification inside a high temperature confocal scanning laser microscope (HT - CSLM). It has been shown that this technique can distinguish the difference between solidification paths of a range of steels. This mimics techniques such as calorimetry, however this technique offers the ability to observe the sample while also obtaining cooling rates outside the range of standard calorimeters. The thermal data was analysed from the crucible and multiple points on the sample's surface, giving information on both the global and local emittance during solidification. When looking at the results, several differences were seen between peritectic and non-peritectic steel samples. This includes differing level of heat transfer as well as spatial fluctuations/variations in thermal stability.