First, what is sand casting
Sand casting - a casting method for producing castings in a sand mold. Steel, iron and most non-ferrous alloy castings can be obtained by sand casting. Since the molding materials used for sand casting are cheap and easy to obtain, the molds are easy to manufacture, and can be adapted to single-piece production, batch production and mass production of castings. For a long time, it has been the basic process in casting production.
Second, what is the sand casting process
Sand castings are the most popular and simplest types of castings that have been used for centuries. Sand casting is used to make sand castings for large parts such as grey cast iron, ductile iron, stainless steel and other types of steel. The main steps include painting, mold, core making, molding, melting and pouring, cleaning, etc.
1. Drawing of the sand casting process:
The traditional method is to take the foundry drawings and then send the drawings to the foundry. This process can be done in the quotation. Today, more and more customers and foundries use computer-aided design instead.
2. Mould for sand casting process:
In sand casting, the mold is made of wood or other metal materials. In this process, we asked our engineers to make the mold size slightly larger than the finished product, and the difference is called the shrinkage allowance. The purpose of this is to melt the metal into the mold to ensure that the molten metal solidifies and shrinks, thereby preventing voids in the casting process.
3. The core of the sand casting process:
The core is formed by casting resin sand into a mold to form a casting of the inner surface. Therefore, the gap between the core and the mold eventually becomes a casting.
4. Forming of sand casting process:
A mold is required during the smelting process. Molding typically involves the support frame of the mold, which is pulled out to separate during the casting process, where the previously placed core melts in the mold and then closes the die opening.
5. Cleaning of the sand casting process:
The purpose of cleaning is to remove sand, sand and excess metal in the casting. Welding, sand removal can improve the appearance of the casting surface.
The burnt sand and scale were removed to improve the appearance of the casting. Excess metal and other risers are clear. Further steps such as welding and grinding. Finally check the defects and the overall quality.
6. Finishing of sand casting process:
Before processing, re-processing. According to the requirements of different customers, we can do heat treatment, surface treatment, additional inspection and so on.