Principles of casting method selection


Sand casting is preferred. According to statistics, 60 to 70% of the castings are produced in sand, and about 70% of them are produced in clay sand. The main reason is that sand casting has lower cost, simple production process and shorter production cycle than other casting methods. Therefore, castings such as the engine cylinder block, cylinder head and crankshaft of the automobile are produced by the clay wet sand molding process.

When the wet type does not meet the requirements, consider using a clay sand table dry sand type, dry sand type or other sand type. Clay wet sand castings can weigh from a few kilograms up to tens of kilograms, while clay dry castings can weigh up to tens of tons. Generally speaking, for medium and large castings, cast iron parts can be made of resin self-hardening sand type, and steel castings can be produced with water glass sand type, and castings with precise dimensions and smooth surface can be obtained, but the cost is high.

Of course, casting precision, surface finish, material density, metallographic structure, and mechanical properties of sand casting are often poor, so when these performance requirements of castings are higher, other casting methods should be used, such as investment casting. Wax) casting, die casting, low pressure casting, etc.The casting method should be compatible with the production batch, such as sand casting. The mass production of the factory should create conditions using advanced technology modeling and core making methods.

The productivity of the old shock-type or shock-pressure molding machine production line is not high enough. The labor intensity of the workers is large, the noise is large, and it is not suitable for the requirements of mass production. It should be gradually modified. For small castings, it is possible to use a horizontal or vertical type of boxless high-pressure molding machine production line, real modeling and high production efficiency, and a small footprint; for the middle parts, various high-pressure molding machine production lines and gas can be selected. The molding line is designed to meet the requirements of fast and high-precision molding production lines.