What is Forgeability of metals?
Definition: Forgeability is defined as the ability of the metal to experience deformation without cracking or failure.
Forgeability is a very important property of the metals which is taken into consideration for selecting the material for a forging process.
The amount of deformation that a metal can withstand without failure is directly related to the forgeability of the metal.
If the deformation of metal is higher, then its forgeability is also higher. (Note: This deformation should be without failure).
There are mainly two Forgeability tests which are widely used for metals.
- Upsetting test
- Hot twist test
Apart from these two tests, there are other tests like impact test, etc that are used in forging manufacturing industries.
#1) Upsetting test
In an upsetting test, the cylindrical metal piece is compressed between two flat die. This is called upsetting the workpiece and hence this test is known as an upsetting test.
In an upsetting test, the metal piece is hammered in an open flat die which reduces its height until the cracks form.
The amount of reduction that occurs during this hammering operation decides the forgeability of the test metal.
The upsetting test is performed at different temperatures and at different speeds for accurate results.
Because of upsetting tests being done at different temperatures, its optimum conditions for forging can be found out.
#2) Hot twist test
In a hot twist test, a round bar is taken as a test specimen.
This round bar is twisted in one direction until it’s failure occurs.
The forgeability is determined by the amount of rotation that the rod takes without failure.
This hot twist test is performed at different temperatures, so that the optimum forging conditions can be found out.
By using a forgeability test, the negative effect of stress, strain rate, temperature, etc can be determined easily.