Possibilities of complex experimental study of thermophysical and thermodynamic properties of selected steels

Abstract

In this paper, selected key thermophysical and thermodynamical properties of steels (three alloys based on Fe–C–Cr) such as solidus (TS) and liquidus (TL) temperatures, peritectic transformation temperatures (TP), heats of fusion (ΔHF), specific heat capacities(cP), surface tension (σ), and wettability expressed by the wetting angle (θ) of liquid steel on alumina substrate were experimentally determined in a high-temperature area up to the temperature of 1600 °C. The effect of the temperature and the chemical composition of steel on these properties was investigated using 3D heat flux DSC (Differential Scanning Calorimetry) and a sessile drop method. The interaction of the steel samples with the alumina substrate was studied by SEM, EDX and XRD methods. To assess the influence of the major elements (carbon and chromium), the steels with different carbon and chromium content, which varied in the range of 0.077–0.381 wt.% and 0.049–4.990 wt.%, were chosen. It was shown that increasing carbon and chromium content led to a decrease in phase transformation temperatures and thermal capacities, as well as an increase in the heat of fusion, surface tension, and wetting angle. Furthermore, the rising temperature increases the thermal capacities and wetting angles. Whereas the surface tension followed the opposite trend. Keywords: Fe–C–Cr alloys, Surface properties, Phase transition temperatures, Heat of fusion, Heat capacity, Interface (liquid metal/solid ceramic phase)