Mechanical Properties of a Stainless Steel after Annealing in Uranium Carbide

Abstract

The aim of this study was to investigate the interaction of carbide nuclear fuels with steel that is being used as cladding material for nuclear reactors. The specimens prepared from steel EN 1.4988 were consecutively annealed in three uranium carbide (UC) powders, having different carbon contents, at 600 °C for 1000 h. Both Ar and Na were used as bonding elements. The increase in the carbon content of the carburized specimens was determined and evaluated according to the bound and free carbon contents in the UC powders. The migration of free and bound carbon atoms into steel via self-diffusion and over Fe3C formation is interpreted as carburizing. Microhardness measurements and stress-strain tests were used to determine the mechanical properties of crude and carburized steel specimens. Maximum hardness at the contact surface and depth of the carburized zone were determined from the microhardness profiles and discussed depending on the bonding elements and carbon content in the specimens. These variables have a significant impact on the elongation percent, 0.2% yield stress, and tensile stress.