How to determine the casting surface of precision casting
- 2019-11-25-

Selection principle of pouring position:

1. The important processing surface or main processing surface of the precision casting is facing down or on the side: during pouring, the gas, slag in the molten metal and the sand in the mold will float up, which may cause pores, slag, and slag in the upper part of the casting. Defects such as blisters, and the possibility of defects in the lower part of the casting, the structure is denser.

a. The pouring position of the machine bed should have the guide rail face down to ensure the quality of this important working surface. The quality of the circumferential surface is relatively high, and the vertical casting scheme is adopted to make the circumferential surface on the side to ensure uniform quality.

2. The large plane of the precision casting is facing downward or inclined pouring: due to the strong heat radiation of the hot molten metal to the upper part of the mold during pouring, the top surface of the sand mold will expand and arch or even crack, causing sand inclusions, sand holes, etc. on the large surface defect. The large flat surface is facing down or the method of inclined pouring can avoid the large flat surface production casting defects.

3. The thin wall of the precision casting is facing downwards, standing on the side or inclined: In order to prevent the thin wall of the casting from producing cold barriers and failing to pour defects, the thin wall with a larger area should be placed in the lower part of the casting, or placed on the side wall or Tilt position.

4. Most of the thickness of precision castings should be placed on the top or on the side of the parting surface. The main purpose is to facilitate the placement of risers in thick areas for feeding.