Control method for producing low temperature spheroidal graphite cast iron

The invention discloses a control method for producing low temperature spheroidal graphite cast iron, and relates to spherical graphite-containing cast iron alloy. The control method comprises the following steps of: weighing 3.4 to 3.9 mass percent of C, 1.8 to 2.5 mass percent of Si, 0.1 to 0.4 mass percent of Mn, 0.035 to 0.07 mass percent of residual Mg and the balance of Fe, smelting and desulfurizing in a cupola furnace, transferring to a medium-frequency induction furnace for continuous smelting, adding a spheroidizing agent and an inoculators for spheroidization and inoculation, and casting to obtain a spheroidal graphite cast iron casting for a wind turbine. In the method, by controlling the components of the spheroidal graphite cast iron and improving a spheroidization and inoculation process, the number, size, morphology and distribution of graphite nodules are controlled; the cupola furnace and the medium-frequency induction furnace are adopted for double smelting; and the produced spheroidal graphite cast iron casting meets the impact toughness requirement and strength requirement at low temperature of wind turbine castings, and overcomes the defect that deformation or stress concentration easily occurs when the spheroidal graphite cast iron casting is subjected to heat treatment in an annealing mode, and defect of high cost in the prior art.