Using the vertical pouring process, it is necessary to insert an intermediate diaphragm at the junction of the two metals. It is found that the material, derusting method, thickness and metal liquid temperature of the diaphragm may affect the bonding quality of the composite layer. During the pouring process, the pouring speed of the two metals needs to be well controlled to make the liquid level of the two metals rise at the same speed on both sides of the diaphragm, otherwise the diaphragm will tilt to the side with low pressure due to the pressure difference, and the treatment process of the vertical pouring process scheme will be more complex. In addition, the vertical pouring process forms a large temperature gradient from the bottom to the top, resulting in the layer by layer solidification of the material from the bottom to the top. According to the liquid metal forming theory, it will cause the component segregation, which will make the cast liner composition uneven on the surface of the cast liner working layer, affect the service life of the cast liner, and it is difficult to promote in production.
The horizontal pouring process refers to the molding at the horizontal position of the mold. The box is closed and poured. Two kinds of metals are poured separately. One kind of metal liquid is poured first. After cooling for a period of time, the other kind is poured. The poured metal liquid will rub the metal surface to be solidified again. The advantages of this process are that the molding and pouring system are relatively simple, the field equipment is easy to arrange, and the floor space is small, It can form a true metallurgical combination, so the horizontal pouring process is selected.
However, it should be noted that the pouring temperature and pouring interval of two metal liquids are the key process parameters to obtain qualified bimetal castings. If the control is not good, it is easy to have such defects as mixing, poor bonding, cold shuts and cracks.