FOUNDRY SHOP MANUFACTURING PROCESS

A foundry is an operating plant which manufactures castings of metal, both ferrous and non-ferrous. Metals are processed by melting, pouring, and casting. Iron is the most common base element processed in a modern foundry. However, other metals, such as, aluminum, copper, tin, and zinc, can be processed.

A foundry accomplishes the processing of creating molten metal by using a furnace. The furnace is one of the main parts of a contemporary foundry. Different types of Furnaces are:

Cupola : Most primitive type; ulitlizes

coke as energy for melting.

Induction Furnace: Most common melting unit;

utilizes electricity as energy

for melting; operate like a

transformer at high frequency,

where, primary is the coil,

secondary is the charge.

Arc Furnace : Another common melting unit;

utilizes electricity as energy

for melting; operate like a

welding machine, melting by

arcing; it is usually known as

steel making unit since slag

can be manipulated to reduce

impurities, such as, sulfur and

phosphorus.

More about Furnace:

Furnaces use insulated, heated vessels powered by an energy source to melt metal. Furnace design is a complex process, and the design can be optimized based on multiple factors. Furnaces in foundries can be any size, ranging from mere ounces to hundred of tons, and they are designed according to the type of metals that are to be melted. Also, furnaces are bound by the fuel available that will produce the desired temperature. For low temperature melting point alloys, such as zinc or tin, melting furnaces may reach around 600 Kelvin or 327 OC. On the high end, from steel, nickel based alloys, tungsten, all the way to other elements with higher melting points, furnaces can reach to over 3600 Kelvin or 3327OC. The fuel used to reach these high temperatures can be electricity, natural gas or propane, charcoal, coke, fuel oil, or wood. The majority of foundries specialize in particular metals and have furnaces dedicated to these metals.

For example, an iron foundry (for cast-iron) may use a cupola, similar to a small blast furnace. While a steel, bronze, or brass foundry will normally use an electrical induction furnace. However, in some cases, they may use a gas heated crucible furnace. Most aluminum foundries use either an electric resistance or gas heated crucible furnace.

Pouring Technique:

In a foundry, molten metal is poured into molds. Such molds may be made of sand, metal for permanent molding, ceramic, or refractory materials. The pouring can be accomplished with gravity, or it may be assisted with a vacuum or pressurized gas.

Casting:

When the molten metal changes states from liquid to solid, it is said to be cast into shape.

Advantages:

The finished product of a foundry can be more versatile than the product of a rolling process. Also, the process of casting molten metal, as is occurs in a foundry, can be far more automated.