Niobium- and molybdenum effect on Fe-Co-Cr alloy ageing

The influence of niobium- and molybdenum small additions on the Fe-Co-Cr system alloy aging has been studied versus the iron, cobalt- and chromium content. The temperature of 898 K is shown to be the optimum one for aging as namely at this temperature a maximum coercive force increase has been observed as compared with other temperatures. Niobium addition improves the alloy magnetic properties, whereas molybdenum stabilizes the high-coercive state. The alloy aging upon various heat treatments is investigated. Two step (913 K+863 K) and three step (1523 K+898 K+863 K) integrations have been studied. It is pointed out on the whole that holding the alloys at integrated temperatures considerably enhances the coercive force of the Fe-Co-Cr system alloys as compared with treatment at a single temperature