Why castability of cast iron is better than cast steel?

Both cast iron and cast steel are the important materials used for castings in china. But the castablility of cast iron is better than cast steel.

There're some reasons which cause the difference.

1)Melting point

Melting point of steel is much higher than iron. It takes long time to melt steels. During casting process, the steel water is easily oxidized.

2)Liquidity 

Liquidity of iron is better than steel during casting process. Percentage and numbers of elements in steel are more than iron. These elements, such as Si, Mn, Al will easily create a chemical reaction with other elements to achieve kinds of maters, which will affect the liquidity of steel water. Main components for iron is Fe. The simplex chemical elements is good for iron casting. 

3)Shrinkage

Shrinkage of casting steel is bigger than cast iron. The cast body shrinkage is around 10 -14% and it's line shrinkage is about 1.8-2.5%. Generally, the higher casting temperature required, the shrinkage rate will be increased. The high melting point of cast steel required a high temperature during melting process. This will cause the big shrinkage risks inside the steel castings. Melt point of cast iron is low. Thus, shrinkage problem is less than cast steel. Big shrinkages will affect liquidity of steel waters, thus affect the castability of
steel during casting process. 

Due to the different castability, casting process is different to make the iron castings and steel castings in our foundry. We choose lost foam casting process and sand casting process to cast iron castings mainly. But for steel castings, we choose the investment casting process. These processes are determined by the castability, sizes, structure and accurancy requirement of iron castings or steel castings. 

We are equiped with profenssional workers, production lines and also quality control systems. We can give you a good suggestions on materials for your castings by known the design founctions of your products. If you have RFQs for steel castings and iron castings, please contact us. We can work together to achieve the high qualified castings for your systems.