Explain Forging with advantages.

Forging :-

• Forging is an oldest shaping process used for the producing small articles for which accuracy in size is not so important.

• The parts are shaped by heating them in an open fire or hearth by the blacksmith and shaping them through applying compressive forces using hammers.

• Thus forging is defined as the plastic deformation of metals at elevated temperatures into a predetermined size or shape using compressive forces exerted through some means of hand hammers, small power hammers, die, press or upsetting machine.

• It consists essentially of changing or altering the shape and section of metal by hammering at a temperature of about 980°C, at which the metal is entirely plastic and can be easily deformed or shaped under pressure.

• The shop in which the various forging operations are carried out is known as the smithy or smith’s shop. A metal such as steel can be shaped in a cold state but the application of heat lowers the yield point and makes permanent deformation easier.

• Forging operation can be accomplished by hand or by a machine hammer. Forging processes may be classified into hot forging and cold forgings and each of them possesses their specific characteristics, merits, demerits and applications.

Advantages of forging :-

Some common advantages of forging are given as under.

• Forged parts possess high ductility and offers great resistance to impact and fatigue loads.

• Forging refines the structure of the metal.

• It results in considerable saving in time, labor and material as compared to the production of similar item by cutting from a solid stock and then shaping it.

• Forging distorts the previously created unidirectional fiber as created by rolling and increases the strength by setting the direction of grains.

• Because of intense working, flaws are rarely found, so have good reliability.

• The reasonable degree of accuracy may be obtained in forging operation.

• The forged parts can be easily welded.

Disadvantages of forging :-

Few dis-advantages of forging are given as under.

• Rapid oxidation in forging of metal surface at high temperature results in scaling which wears the dies.

• The close tolerances in forging operations are difficult to maintain.

• Forging is limited to simple shapes and has limitation for parts having undercuts etc.

• Some materials are not readily worked by forging.

• The initial cost of forging dies and the cost of their maintenance is high.

• The metals gets cracked or distorted if worked below a specified temperature limit.

• The maintenance cost of forging dies is also very high.

Applications of forging :-

• Almost all metals and alloys can be forged. The low and medium carbon steels are readily hot forged without difficulty, but the high-carbon and alloy steels are more difficult to forge and require greater care.

• Forging is generally carried out on carbon alloy steels, wrought iron, copper-base alloys, alumunium alloys, and magnesium alloys. Stainless steels, nickel?based super-alloys, and titanium are forged especially for aerospace uses.

• Producing of crank shaft of alloy steel is a good example which is produced by forging.

• Forging processes are among the most important manufacturing techniques utilized widely in manufacturing of small tools, rail-road equipments, automobiles and trucks and components of aeroplane industries.

• These processes are also extensively used in the manufacturing of the parts of tractors, shipbuilding, cycle industries, railroad components, agricultural machinery etc.