Thermo-Physical Properties of HR3C and P92 Steels at High-Temperature

Abstract

Austenitic HR3C and ferritic-martensitic P92 steels are the materials of interest from a mechanical standpoint for the manufacturing of thermal exchangers of the next generation of steam power plants. In order to evaluate their capacity to transfer heat, thermal conductivity calculations have been conducted through the measurements of thermal diffusivity, specific heat capacity and density. It will be shown that the heat capacity, density, thermal expansion coefficient and thermal diffusivity evolve continuously with temperature in the HR3C material but not in the P92 steel. The heterogeneous thermal behaviour appears to be associated with its ferromagnetic transition rather than to the microstructural evolution. Nevertheless, the results for both steels did not exhibit significant differences between thermal conductivities at the intended temperature of service.