Abstract
Cast irons, containing both copper and Molybdeunm, were studied. Cn the graphitization, copper and molybdenum have the contrary effect and the relation between the microstructure and the chemical composition is not simple. In general, molybdenum has somewhat a more powerful effech than copper. Both hardness and impact resistance of cast iron are increased with the addition of copper and molybdenum, but there is a limiting amount which makes the irons brittle. Copper-Molybdenum cast irons containing more than 0.5% molybdenum have more or less a white needleshaped structure, which is somewhat like martensite.
