Views: 0 Author: Site Editor Publish Time: 2023-11-02 Origin: Site
1. Important machining surfaces or main machining surfaces of precision castings should be facing downwards or located on the side: During casting, gases, slag, and sand particles in the metal melt may float up, potentially causing defects such as porosity, slag inclusions, and sand holes on the upper part of the casting. On the other hand, defects are less likely to occur on the lower part of the casting, resulting in a denser structure.
2. The casting position of the machine bed should have the guide rail surface facing downwards to ensure the quality of this important working surface. The quality requirements for the circumferential surface are higher, and using a vertical casting scheme can place the circumferential surface on the side, ensuring uniform quality. The thicker parts of precision castings should be placed on the top or on the side of the parting surface, mainly to facilitate the placement of risers for feeding and shrinkage.
3. The large flat surface of precision castings should be facing downwards or cast at an angle: During casting, the hot metal melt radiates intense heat to the upper part of the mold, causing the top surface of the sand mold to expand and even crack, resulting in defects such as sand inclusions and sand holes on the large flat surface. Casting the large flat surface downwards or using an inclined casting method can avoid production casting defects on the large flat surface.
4. Thin walls of precision castings should be facing downwards, on the side, or cast at an angle: To prevent the occurrence of cold shuts and incomplete filling in the thin wall areas of castings, larger thin wall areas should be placed on the lower part of the casting or positioned on the side or at an angle. The position of the casting in the mold during the casting process will affect the quality of stainless steel precision casting, dimensional accuracy, and the difficulty of the molding process.
5. Principles for selecting casting positions: Important machining surfaces or main machining surfaces of precision castings should be facing downwards or on the side. During casting, gases in the molten metal, furnace slag, and sand in the mold will float. This may cause defects such as holes, slag inclusions, and bubbles on the upper part of the casting, while defects may occur on the lower part of the casting. This ensures a dense structure.
6. Large flat surfaces in stainless steel precision casting can be prone to defects such as sand inclusion and sand holes due to intense heat radiation from the molten metal on the upper part of the mold, causing the sand mold to expand. To prevent casting defects in large-scale production, the casting method of placing the large flat surface facing downwards or at an angle can be employed.
7. In the case of thin-walled sections in precision castings, it is advisable to position the larger area of the thin wall either at the bottom part of the casting or on the side or inclined position to prevent the cold partition from flowing in or not flowing out. The majority of the thickness of the precision casting should be placed on the top or side of the parting surface. The main purpose is to facilitate the insertion of risers into the thick-walled sections.