Abstract
A new method using a relatively short cylindrical bar as a test piece was proposed for measurement of thermal diffusivity of some cast irons, and the theoretical treatment and the reliability and accuracy of the method were discussed. Also, heat transfer coefficient on the surface of a test piece and the temperature difference between the initial and the final states of the test piece were found from the experiment to be small in their influence on the measured results. Furthermore, the thermal diffusivity of cast irons was measured and tabulated as a function of spheroidicity, showing that the so-called compacted-vermicular graphite cast iron was much closer to the flake graphite rather than to the spheroidal graphite cast iron in its heat transfer characteristics at around 300°C.
