Key Casting Processes
The earliest cast-iron artifacts can be dated back to around the 5th century BC, the archaeologists found evidence that at that time in Jiangsu China the people were able to make the items by using the basic iron casting process. Cast iron is comparatively brittle, it is not suitable for purposes where a sharp edge or flexibility is required. But the ancient Chinese craftsman developed a method of annealing cast iron by keeping hot castings in an oxidizing atmosphere for a week or longer in order to burn off some carbon near the surface in order to keep the surface layer from being too brittle. Among the typical cast iron are plowshares, pots, weapons, and pagodas.
In the west, the iron cast does not exist until the 15th century. But it's early applied is for cannon and gun. Henry Ⅷ initiated the casting cannon body in England, the English ironworkers using blast furnaces developed the technique of producing cast-iron cannons, which is much cheaper than bronze cannons. It helps England massively arm her navy battleships. In the 18th century, the application of the steam engine was a key factor in increasing the production of cast iron, which surged in the following decades.
After hundreds of years of development, iron casting techniques made great advances. However, instead of vacuum die casting process, the most basic type of iron casting is sand casting, also known as sand molded casting which uses sand as the mold material, including sodium silicate sand casting. By understanding the manufacturing process of sand casting, it will be easier to understand other types of the iron casting process, such as silica sol casting.
Iron Casting Process Steps
In brief, the iron-casting process involves 6 steps:
1. Place a pattern in the sand to create a mold.
2. Incorporate the pattern and sand in a gating system.
3. Remove the pattern.
4. Fill the mold cavity with molten metal.
5. Allow the metal to cool.
6. Break away the sand mold and remove the casting.