(1) The simulation flow of numerical simulation software is introduced, and the setting of simulation parameters of reducer box body casting is described in detail.
(2) The filling and solidification processes of the three schemes of the reducer are simulated, and the positions of air entrainment, sand washing, shrinkage porosity and shrinkage defects that may occur in the filling and solidification process of each scheme, as well as the feeding energy effect of the feeding riser are analyzed respectively Finally, the effects of different gating systems on theof tractor box are compared and analyzed in terms of defects. Finally, the appropriate scheme is determined as the stepped Pouring Scheme. Using this scheme, the shortest filling time is 0.57s and the solidification time is 161s. The filling process is stable without air entrainment, and the defects after solidification are the least.