Steel and Aluminum Casting and the Different Methods Used
Whenever cast irons are not capable of delivering adequate strength or the necessary level of resistance to shock, steel and aluminum castings are used. Some examples include forging presses, valve and pump bodies, railroad car frames, mining machinery, marine equipment, hydroelectric turbine wheels, and gears. These castings are broken down into two main groups, alloy steel and carbon steel.
One of the methods used for steel or aluminum casting is called the Szekely method. For this method, metal molds that are coated with paraffin and chalk are used. With the Slavianoff electric casting method, stainless steel is melted when it connects to one terminal that has a much stronger electric current. Attached to the other terminal is the plate on which it will be cast or the crucible to which it will be melted.
In the sand core process, the core is cast in the ingot and then worked down. While some experts believe the material is not damaged by the sand, others disagree. With Norton’s fluid rolling process, fluid sand is worked directly into sheets. This is done by the steel being poured through rolls that revolve. With this method, the amount of scale is reduced and blowholes are prevented.
Another method of steel and aluminum casting is called Bessemer. With this method, continuous sheets of molten steel run in between two steel rolls that are cooled by water. There is also Whiteley’s process for manufacturing plates. In this process, molten steel is run into a cylinder that revolves. From there, the steel is formed into a shell. Once taken out, a saw is used to cut the shell open, which is then rolled down.
Two additional processes used for stainless steel and aluminum casting are Mueller and Pielsticker. Both of these methods are used to manufacturer rods, bars, and other materials similar to fluid stainless steel. The castings of stainless steel are passed through dies first, followed by the finished material being processed under a hammer or through a rolling mill. The Falk and Chalk methods are similar in that a boss or sleeve of cast iron is united on a shaft made of wrought iron. The shaft is then heated to a temperature for welding, placed into a suitable mold, and then poured around the molten metal.