Comparing Metal Forging to Casting

Different types of metals such as iron, steel, aluminum, copper, and lead are essential raw materials for a multitude of industries, including the construction, fabrication, shipbuilding, and automotive industries. When it comes to producing metallic structures and components, particularly using steel and iron, there are generally two methods of shaping and molding the metal – forging and casting.

What is Casting?

Casting is a method of forming metal where the material is first heated and melted in a furnace. The molten metal is then poured into molds that shape the metal as it cools and solidifies. After the metal cools, rough edges can be ground out, and the surface refined through polishing and abrasive scrubbing. This method can be used to produce both iron and steel metal parts.

Casting is generally used to create large metal parts weighing hundreds of kilos or those with shapes that are too complex for other methods of molding. During casting, materials like carbon, nickel, chrome, and molybdenum can be added during the melting stage to add strength to the final product or alter other characteristics since raw casts can be brittle and inconsistent.

What is Forging?

In forging, the raw material is subjected to heat (but is not melted) and mechanical force to shape and cut it into the desired form. The resulting iron or steel forgings have better characteristics in terms of durability and strength compared to casts. Forging involves repeated hammering, heating, and pounding to provide sufficient mechanical and heat treatment to the metal. The continuous deformation process results in uniformity, grain refinement, and metallurgical recrystallization, hence the superior quality of forged parts.

Forging requires more energy and time compared to casting. For this reason, only small components can be forged at a time, for instance, sheets and panels weighing less than 100 KGs. However, highly specialized forging facilities can form much larger and heavier pieces for specific applications.