After the methodological null graphite spheroidizing or the graphite spheroidizing which decide

摘要

PROBLEM TO BE SOLVED: To provide a method for quickly and easily determining the number of graphite grains in a spheroidal graphite cast iron obtained at the stage of a molten cast iron to which a graphite spheroidizing process and an inoculation process are applied.;SOLUTION: The graphite spheroidizing process is applied to the molten cast iron. Alternatively, the inoculation process is applied to the molten cast iron after the graphite spheroidizing process. The molten cast iron is accommodated in a predetermined sample collection container, and cooled. While at least a supercool inversion temperature (TSC) is found from a cooling curve obtained from a cooling process and its differential curve, a graphite eutectic temperature (TEG) and a cementite eutectic temperature (TEC) of the molten cast iron are found. The number of the graphite grains in the spheroidal graphite cast iron obtained from the molten cast iron is determined from a relative relationship between the number of the graphite grains and the degree of graphitization based on the degree of graphitization [ΔT1/ΔTE=(TSC-TEC)/(TEG-TEC)] calculated from the temperatures.;COPYRIGHT: (C)2011,JPO&INPIT