What is forging press?
A forging press is a type of forging process in which the metal is shaped between the two dies by using mechanical or hydraulic pressure.
In forging press, the forging of workpiece is carried out in a single work stroke at each die station.
In forging presses, the continuous pressure is applied to the metal in order to deform it.
In drop forging, the contact of the dies with the workpiece is in milliseconds, while in forging press, the time of contact between dies and workpiece is in few seconds.
Forge press is sometimes called as blacksmith forging press, hydraulic press, hydraulic forging press, or mechanical press forging.
Hot forge press as well as cold forge press can be performed on metals using forging press machines.
Types of Forging Presses
There are mainly 2 types of forging presses.
#1) Hydraulic forging presses
Hydraulic forging press: Hydraulic forging press is a type of forging machine in which the forging action is carried out by means of hydraulic system where ram moves up and down in a cylinder by hydraulic pressure.
In hydraulic forging press, the ram moves downward along with a die due to the high amount of hydraulic pressure applied on the ram.
During this working stroke, the metal piece is forged between the upper die and lower die. After this, the ram again moves in upward direction by means of hydraulic pressure only.
#2) Mechanical forging presses
Mechanical forging press: Mechanical forging press is a type of forging machine in which the forging action is carried out by means of a mechanical system and the die moves up & down by mechanical forces.
There are basically 2 types of mechanical forging presses.
- Crank press
- Screw press
In crank press, the force required to squeeze the workpiece is obtained from the rotating flywheel.
In screw press, the energy required to forge the metal is obtained from the flywheel which is further connected with the screw and upper die.
Advantages of forging press
Advantages of forging presses are mentioned below.
- By using forging press, the entire surface of the workpiece comes in contact with the die. This is advantageous over drop forging, because in drop forging the workpiece remains only in contact with the anvil and hammer.
- The compression rate of the workpiece in a forged press operation can be controlled. So we can come to know the strain rate of the workpiece.
- Press forging is comparatively more economical and more productive than drop forging, when heated dies are used.
- In forging presses, higher dimensional accuracy is obtained.
- In hammer forging, most of the energy is absorbed by the machinery. While in forging presses, most of the energy is used to deform a workpiece.
Disadvantages of forging press
Disadvantages of forging presses are mentioned below.
- The time required to forge a metal in forging press is more, because there are few steps involved in the process plus each compression process takes time to get the desired shape.
- The cooling of workpiece is faster as the workpiece remains in contact with the dies which are at lower temperature. Also the dies conducts more heat as compared to the surrounding atmosphere.
- As the cooling of workpiece is faster, it becomes less ductile, and this may develop cracks on the surface if deformation continues.
- Thus the dies are required to be preheated in press forging process in order to avoid the rapid cooling of workpiece.
- In some cases, the workpiece is required to be reheated for its further deformation.
Uses/Applications of forging press
Uses/applications of forging presses are mentioned below.
- Forging press is used to perform all the forging operations, including open die forging as well as closed die forging.
- Press forging can be done in a single closing too. This allows its use in automated forging operations.