A continuous casting machine is a device used to cast molten metal in an ongoing stream; it commonly is used with steel and copper. This process begins in a small bowl — called a ladle — that heats up and melts the metal, which then is poured into a larger bowl, called the tundish. After the metal cools slightly, it travels into a mold and goes through rollers that further mold it. As the metal travels, it is cooled to ensure it keeps its shape. The metal is moving throughout the entire process, so complex shapes typically are difficult to make with a continuous casting machine.
To begin the cast with a continuous casting machine, metal is placed in a ladle. The metal may previously have been melted in a large furnace, or the ladle may be heated to melt the metal. A small tap allows the metal to travel into the tundish, which is a larger bowl in the casting machine. Tapping is used to keep the metal from flowing too quickly, and the tap can be turned off if the tundish is full.
The molten metal will be cooled slightly in the tundish to make it easier to cast. A larger tap in the tundish allows the metal to travel onto a mold. This is the part of the continuous casting machine that shapes the metal into its final shape, though the metal technically still is molten at this stage. Pressure from the machine causes the metal to constantly run from the tundish to the mold, which makes the process continuous.
Rollers are used right after the mold to further shape and push the molten metal. These usually keep the metal straight and, because the rollers are cooled with water, it will begin cooling and solidifying the metal. The continuous casting machine finishes the metal at this point and it is pulled from the machine.
A continuous casting machine's setup means the casts must be very simple. This machine normally only makes strands, wires and straight shapes because they are easy to mold and make continuously. Complex shapes, such as faucets or machine parts, would be difficult to cast continuously, because the machine would have to stop to finish the cast. Other molding machines often are coupled with this one to process the strand or wire, making it flatter or longer so it can be used for other purposes.
