In this article we will learn following things about forging
- What is forging?
- Forging operations
- Forging defects
What is forging?
Attribution: By Rainer Halama – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10689973
Forging is a manufacturing process in which shape of a heated metal changed by applying external force. Heated metal is used in forging because it is much easy to reshape heated material compared to colder one.
However, in many forging operations cold metal is also used.
There are basically two types of forging operations
In this type of forging operation, a metal is elongated and as a result its cross-sectional area decreases.
Upsetting is opposite to drawing out operation. In upsetting cross-sectional area of the workpiece is increased and as a result length of workpiece decreased.
There are basically four types of forging
Smith forging is the same which a village blacksmith uses for making various tools. In smith forging the heated metal gets repeated blows of hammers to get desired shape.
This is the operation done in close impression dies by means of drop hammers. Here the Force for shaping is applied in several blows.
Press forging is same as drop forging but, the force is applied here with the help of hydraulic machines.
The only difference in press forging and machine forging is that, in press forging material is drawn-out but in machine forging material is upset.
Though the products manufactured by forging are of superior quality as compared to other manufacturing process but there are still some defects which could arise.
- Unfilled sections
- Cold shut
- Scale pits
- Die shift
- Improper grain flow
Advantages of forging
These advantages are in comparison with other manufacturing processes.
- Parts manufactured by forging are stronger
- It is more reliable and less costly
- It offers better response to heat treatment
- It offers more consistent and better metallurgical properties
- It offers broad size range of products
- It requires fewer secondary operations
- It has great design flexibility
Disadvantages of forging
- In hot forging it is difficult to perform secondary operations
- Capital cost is more
- Very high man and material safety procedures need to be followed
Applications of forging
- Automobile industry
- Valves and fittings
- Hand tools and hardware
- Machinery and equipment