Types Of Forging Machines And Equipments.

Introduction :

Forging is the Oldest of the metal forming operations. It is a Deformation process in which work is compressed between two dies.

Forging can produce a piece that is stronger than an equivalent cast or machined part. As the metal is shaped during the forging process, its internal grain deforms to follow the general shape of the part.

As a result, the grain is continuous throughout the part, giving rise to a piece with improvedstrength characteristics. Other advantages include less noise, heat and vibration. It also produces a distinctly different flow pattern.

Types of Forging :

Hot Forging :The hot-forging is the operation of forging product or components above the recrystallization temperature for that product.

The other reasons that favours the application of hot-forging are:
1. Strength coefficient is substantially less than at room temperature.
2. Strain hardening exponent is zero (theoretically).
3. Ductility is significantly increased.

Advantages of Hot Forging :
1. Lower forces and power requirement than cold working.
2. More intricate work geometries are possible to process.
3. Need for annealing may be reduced or eliminated.

Disadvantagesof Hot Forging :
1. Lower dimensional accuracy.
2. Higher total energy required (due to the thermal energy to heat the workpiece).
3. Work surface oxidation (scale), resulting in a poorer surface finish.
4. Shorter tool life.

Cold Forging : The cold-forging is the operation of forging product or components at the room temperature or above the room temperature, but far below than the recrystallization temperature of the product.

Advantages of Cold Forging :
1. Higher dimensional accuracy
2. Lower total energy required.
3. There is no work surface oxidation or scale, resulting in high surface finish
4. There is a longer tool life.

Disadvantages of Cold Forging :
1. It requires larger forces and power than hot forging.
2. The cold forging cannot be used for complex and intricate shape work parts.

Types of Forging Machines :

Hammers : They are the most common types of machine used. They are often preferred for small to medium batches because of quicker tool setups and lower overheads.

They are also used for elongated and branch-type forgings because die areas can be provided for the larger number of preform dies required for such shapes.

Screw Presses : In screw presses, the upper ram and die are connected to a large vertical screw that can be rotated by a flywheel, so that the ram can move up and down relative to the fixed die in the bed of the machine.

Hydraulic Presses : Hydraulic presses are available in a wide range of sizes up to the largest at 50,000 tons or more capacity. The moving die is attached to a ram actuated by a large hydraulic cylinder. Various strokes, forces, and closing speeds can be obtained on hydraulic presses.

Types of Forging Equipments :

Furnace or hearth:A black smith uses a furnace for heating the metal pieces. Furnace consists of four legs, a cast iron or steel body, iron bottom, a chimney and a blower.

Shovel:It is used to place the coal into the furnace hearth.
Blower: It is used to supply air at high pressure to the hearth.
Poker:It is a bent rod used to strike the fire. Poker is made up of mild steel.

Regulator: It is used to control the air supply of air to the hearth. Air supply is controlled by increasing or decreasing the passage of air.

Anvil: A block on which forging work is done is known as anvil.

Precautions while using Forging Tools and Equipments :

The following points must be kept in mind while working with the forging tools:
1. Hearth should be lightened is proper way.
2. Hammering should not be done in lazy mood.
3. Heavy blows should not be given on the tail of the anvil.
4. Hammers should have proper handle length.
5. Length of the tong should be kept between 15” to 18”. The tong should be kept cool while working with it

6.Blunt chisels should not be used in the forging shop.