Step by Step: The Making of Cast Iron
Iron is rarely ever found in its pure form. The making of cast iron, used to create our signature table bases, starts with a combination of raw materials. The iron we’ve been using for centuries is a combination of iron and other elements, known as iron oxides. Keep reading to learn how iron ores get turned into table bases!
Cast Iron Production
The term cast iron describes grey cast iron, but other alloy groups are included under the umbrella. Cast iron is identified by its surface color, and begins its life as pig iron. By itself, pig iron has very few uses due to its brittle nature. Pig iron is remelted and combined with large amounts of scrap iron, and sometimes with steel. Contaminants are removed from the pig iron and then the melted iron is cast.
Casting is the process of pouring iron into a mold, thus giving it a shape (like a table base). Molds can either be expendable sand molds or non-expendable metal molds. Pouring can take place through gravity, low-pressure, or a vacuum. The pouring process is more important for the end result than the intricacy of the mold.
Cast Iron Solidification
After iron is cast, it must solidify. If solidification is done incorrectly, the effort can be destroyed and the metal will be reused. It will become scrap metal and recycled into pig iron, ready for another round of casting!
Controlling the cooling during solidification is also important. Quick cooling produces fine grain construction and slow cooling results in coarse grain construction. Cast iron that has not been cooled evenly produces low-quality items. During the iron casting process, it’s also important to consider iron contamination, gas bubbles, and metal fluidity. The casting process is a methodical art form!