Production process of sand molding casting

Sand casting is a production method in which molten metal is poured into the mold cavity of a sand mold, cooled and solidified to obtain castings.

Sand casting process flow:

1. Mold making

Making molds is the first step in sand casting, and each casting requires a mold. Sand molds are formed by placing sand into each half of the mold. Sand accumulates around the model, which is a replica of the shape of a casting. After the model is removed, the cavity that forms the casting still exists. No structure can be formed inside the model, and it needs to be implemented by built-in sand cores. Sand molds can be divided into manual molding and machine automation molding. In today's society, casting enterprises will gradually transition to green sand molding machines for automated production in order to improve production efficiency and reduce production costs. In the article "How to improve production efficiency in cast iron casting factories", it is necessary to understand how casting companies can improve production efficiency..

2. Casting

For the convenience of disassembling the casting later, the surface of the cavity should be lubricated first. Then, the core should be placed in the desired position, and the other half of the mold should be closed and fixed together to ensure sealing. After the casting mold is tightened, the melted metal liquid is poured from the insulated furnace into the sand mold. Sufficient metal liquid must be injected to fill the entire cavity and all channels in the sand mold. The pouring time is short to prevent premature solidification of the casting locally.

3. Cooling

After casting, the liquid metal begins to solidify but becomes cold. Most possible casting defects occur during the solidification process, and if cooled too quickly, the casting may experience shrinkage, cracking, or damage. Therefore, corresponding preventive measures should be taken when designing molds and casting systems.

4. Sand cleaning

After the casting is completely solidified and cooled, the sand mold is separated from the casting using a vibration device, and then the surface of the casting is cleaned with a shot blasting machine to remove oxides and sticky sand.

5. Go to the gate

The additional material on the casting produced by the casting mouth is the sprue, which must be removed by various cutting methods and further ground by grinding or machining with a grinding wheel to completely remove it without damaging the part body.

What are the advantages of sand casting?

-Almost any black and non-ferrous metal can be cast using sand casting.

-Parts vary greatly in size, weight, and shape, with weights ranging from ounces to hundreds of tons.

-Any quantity is applicable.

-Mass production has the advantage of low cost.