Cold forging Process is defined as forming or forging of a bulk material at room temperature with no initial heating of the preform or inter- mediate stages. Cold extrusion is a special type of forging process wherein the cold metal flows plastically under compressive forces into a variety of shapes. These shapes are usually axisymmetric with relatively small non-symmetrical features, and, unlike impression-die forging the Cold Forging, process does not generate flash. The terms cold forging and cold extrusion are often used interchangeably and refer to well-known forming operations such as extrusion, upsetting or heading, coining, ironing, and swaging These operations are usually performed in mechanical or hydraulic presses, which are discussed.” Several forming steps are used to produce a final part or relatively complex geometry, starting with a slug or billet of simple shape,. Some basic techniques of cold forging and through a combination of these techniques, a very large number of parts can be produced,
Cold forging Process is extremely important and economical process, especially for producing round or nearly round parts in large quantities. Some of the advantages provided by this process are:
- High production rates
- Excellent dimensional tolerances and surface finish for forged parts
- Significant savings in material and machining
- Higher tensile strengths in the forged part than in the original material, because of strain hardeni
- Favorable grain flow to improve strength
- Increased Tool Life
- Expanding capacity to forge larger and more intricate parts.
- Reducing costs by minimizing scrap losses, by reducing pre- forming steps
By far the largest area of application of cold is the automobile industry. However, cold forged parts are also used in manufacturing bicycles, motorcycles, farm machinery, highway equipment, and nuts and bolts.
All metals that exhibit ductility at room temperature can be cold forged. This group consists primarily of steels and aluminum alloys. However alloys of copper, zinc, tin, titanium, beryllium, and nickel are also cold forged for special applications.