How to produce large iron castings

In China, there are many iron foundries, who mainly produced large iron castings, such as for the balance weights, ship parts, drying cylinders, machine bases and so on. Therefore, there are many different casting processes for producing large cast iron parts. Herein, we mainly introduced some normal casting methods for them.

1. Resin sand casting process

Resin sand casting process is very common casting method to produce middle size iron castings, unit weight from dozens kilograms to Several tons. Resin sand castings have good surface quality and dimension tolerances, and less of casting defects, so this process is usually used for producing complex iron castings with high requirements.

Moreover, this process could use wooden or resin patterns, so can reduce the costs for patterns. This is useful to small annual demand situation.

2. Lost foam casting process

Lost foam casting process have better surface quality than resin sand casting process, and it also can reduce the manpower for molding, which could reduce the molding costs for workers. In China, labors have become more and more expensive, so this process will be a direction of development to casting process for large iron and steel castings.

Moreover, lost foam molding process could produce larger metal castings than resin sand process.

However, this process can emit pollution air, and have to use metal patterns to produce the foam molds, so the high pattern costs will restrict the choice of clients.

3. Buried foundry technology

As for the very large iron castings, such as dozens of tons weight castings, the buried foundry will be the best choice. This process normally uses dry clay sand as the molding material, and put the clay sand into the deep hole, then after molding, pour the liquid iron into the hole.

Of course, this process will have more casting process and worse surface quality than other processes, however, you could repair the defects, and use machining to keep the tolerance for the key positions.

This process is widely used for producing super large iron castings, but normally these foundries will not produce small castings. Their casting and machining workshops are specifically producing large iron castings.

As for producing large iron castings, the iron foundries should have rich experiences and suitable casting process. Lacking either of them will cause the failure and loss.

Home | More Articles