The author accurately measured the influence of various packing materials upon the time required to complete the Graphitization of free cementite in white cast iron with a dilatomater which was newly divised by the author especially for this purpose, and found that roll scale or hammer scale favours it most distinctly. They also decarburise white cast iron at high temperatures in a considerable degree without injuring the surface of castings by their oxidising action.
By measurement of the thermal expansion and the magnetisation during heating and cooling with different rates, the transformation points of manganese steels containing less than 12 percent of manganese and 1.2 percent of carbon were determined. From the result, the relation of their transformation points and compositions or the heating and cooling conditions of steels were thoroughly studied. The microstructures of steels cooled in three cooling conditions, i.e. slow cooling furnace-cooling and air-cooling were observed, and the three structural diagrams corresponding to the respective cooling conditions were constructed and the change of microstructure due to the difference of the composition and the cooling condition were demonstrated.