Influence of Zr on grain orientation, texture, and mechanical properties in hot- and warm-rolled FeCrAl alloys

Abstract

Iron–chromium–aluminum (Fe–Cr–Al) alloys have great potential application as an accident-tolerant fuel cladding material in light-water reactors. It has excellent processing ability, resistance to steam oxidation at high temperatures (HTs), and irradiation swelling-resistance. It is necessary to improve the room- and high-temperature mechanical properties and reveal the strengthening mechanism. In this study, we analyzed the effect of Zr on the microstructure and room- and high-temperature tensile properties of hot- and warm-rolled FeCrAl alloys. The results show that the Laves phase could be effectively stabilized by Zr addition, and the proportion of low-angle grain boundaries increased. Moreover, the yield strength at room and high temperatures of the samples after Zr addition were improved, owing to the precipitation and sub-grain boundary strengthening by Zr. In addition, Zr changed the grain orientation, but had no relevance to the number of easier activated slip systems. The movable dislocation cannot slip during high-temperature tensile tests because of the pinning effect of the dynamic precipitated Laves phase, which could be the reason for the decrease in elongation at high temperatures. • Zr addition stabilized the Laves phase effectively in Fe–Cr–Al alloys. • Zr addition increased the proportion of LAGBs in hot and warm rolled Fe–Cr–Al alloys. • Zr addition did not influence the number soft orientation grains in Fe–Cr–Al alloys. • The elongation of Fe–Cr–Al alloys decreased at the high temperature tensile tests.