1. The molding process (1) adopts the bottom pouring system in order to increase the punching speed. (2) Wall thickness deviation and avoiding quality control, ensuring dimensional accuracy and surface quality; ensuring increased dimensional accuracy. 2. Smelting and pouring process. (2) Rare earth indirectly spheroidizes. In order to improve the anti-recession ability, the use of mixed spheroidizing agents can not only ensure the content of spheroidizing Mg, but also maintain a high anti-recession ability. In the spheroidizing process, in order to improve the absorption rate of magnesium. (3) In order to ensure the quality of molten iron, it is required that the furnace chamber is clean and free of residual molten iron. (5) Start the furnace with high-quality pig iron. 3. Remove the pouring riser, parting surface and mandrel.