Determination of thermal properties of steel for Thermoenergetics

Razvoj jekel odpornih na lezenje za uporabo pri visokih temperaturah in visokih tlakih, poteka v smeri izboljšanja življenjske dobe materiala in boljših mehanskih ter toplotnih lastnosti. V tem delu smo izmerili toplotno prevodnost malolegiranega jekla po njegovi dolgotrajni uporabi pri povišanih temperaturah. Meritve smo izvedli na napravi Hot Disk TPS 2200 po standardu ISO 22007-2 iz skupine standardov ISO 22007. Toplotno prevodnost jekla smo merili pri sobni temperaturi, pri 290 °C in pri 400 °C. Opravili smo tudi analizo mikrostrukture na vrstičnem elektronskem mikroskopu in svetlobnem mikroskopu ter analize kemične sestave z XRF in EDS metodo.Research and development of creep resistant steels for use in high pressure and high temperature environments is based on endeavours to extend the lifetime of material, reduce the cost of maintenance and to improve thermal and mechanical properties of material. In this master’s thesis we discuss the measurements of thermal conductivity conducted on specimens of low alloyed creep resistant steel after use under elevated temperatures in Thermoenergetics. Measurements were performed on the instrument Hot Disk TPS 2200 in accordance to standard ISO 22007-2 from the group of standards ISO 22007. Thermal conductivity was measured at room temperature, at 290 °C and at 400 °C. Microstructure analysis of the steel sample was performed on SEM electron microscope as well as on light microscope. With XRF and EDS methods we also analysed the chemical composition of the steel