Spherical graphite cast iron semi-solid casting method and semi-solid cast product

A semi-solidification casting method for casting a spheroidal graphite cast iron cast product, comprising;

• a melting step in which a raw material made of cast iron is heated and melted to obtain a molten metal,
• a spheroidizing treatment step of spheroidizing the molten metal,
• an inoculation step of inoculating the molten metal, and
• a casting step of pouring the molten metal after inoculation from a pouring port, passing through a runner, and filling a product space through a gate,
• wherein the amount of nitrogen in the molten metal is adjusted so that the amount of nitrogen generated during melting of the casting is 0.9 mass ppm or less,
• the pouring being performed at a temperature between liquidus temperature +10° C. and (liquidus line temperature +40° C.), and
• the molten metal poured from the pouring port is cooled in the runner and introduced into the product space through the gate in a solid-liquid coexistence state.