The lost foam casting / resin sand casting is adopted for machine tool casting. The following points should be paid attention to when casting machine tool castings:

1. During the initial stage of casting, especially when the metal liquid is just in contact with the foam plastics, because of the large amount of gas produced by gasification of the material, when the straight gate is not filled or just started pouring, the static pressure head of the metal liquid is smaller than the gas pressure of the decomposition product of polystyrene. In order to avoid this phenomenon, in the beginning of pouring, the method of first trickle and slow pouring can be adopted. After the gating system is filled with liquid metal, the pouring speed can be increased. The faster the pouring speed is, the better. The molten metal should not be raised at the end of the riser and the molten metal should not be kept at the top of the riser.

2、 The bottom injection bag should be selected as far as possible. The bottom pouring ladle has the advantages of low heat loss, large pressure head, fast pouring speed, slag floating on the surface of liquid metal, and the molten steel is relatively clean. Due to the limitation of equipment conditions, some castings with low requirements or small and medium-sized machine tools can also be poured by subcontract.

3、 The pouring process must not be interrupted. In the process of EPC casting, the liquid metal must be continuously injected until the mold is fully filled. Otherwise, it is easy to cause cold shut defects in the whole plane of the casting at the standstill.