Forge Welding: Principle, Working, Application, Advantages and Disadvantages
Forge welding is a solid-state welding process in which metal joint is created due to inter-molecular diffusion. As we know, forging is a technique of shaping any metal by the application of high pressure and temperature. This welding process uses the fundamental technique of forging to weld similar or dissimilar metals. it has been used from a very old period to join iron or steel workpieces. It was the simplest process of joining two metals in ancient time but now it has replaced by other more suitable and simplest welding processes like arc welding and gas welding.
Forge Welding |
Forge Welding:
Principle:
As we discussed, forge welding is a solid-state welding process in which both plates are heated quite below its melting temperature. This heating deforms the workpieces plastically. Now a repeated hammering or high pressurize load is applied on these plates together. Due to this high pressure and temperature, inter-molecular diffusion takes place at the interface surface of the plates which make a strong weld joint. This is the basic principle of forge welding. One of the basic requirement of this types of welding is a clean interface surface which should be free from oxide or other contaminant particles. To prevent the welding surface from oxidation, flux is used which mixes with the oxide and lower down its melting temperature and viscosity. This allows flowing out the oxide layer during the heating and hammering process.
Forge Welding |
Working:
Forge welding was one of the most applied welding methods in ancient times. This is a fundamental welding process of all-solid-state welding. Its working can be summarized as follow.
- First, both the work plates heated together. The heating temperature is about 50 to 90% of its melting temperature. Both plates are coated with flux.
- Now manual hammering is done by a blacksmith hammer for making a joint. This process is repeated until a proper joint is created.
- For welding large workpieces, mechanical hammering is used which is either driven by an electric motor or by using hydraulic means. Sometimes dies are used which provides finished surface.
Application:
- It is used to join steel or iron.
- It is used to manufacture gates, prison cells, etc.
- It is widely used in cookware.
- It was used to join boilerplates before the introduction of another welding process.
- It was used to weld weapons like sword etc.
- Used to weld shotgun barrels.
Advantages and Disadvantages:
Advantages:
- It is simple and easy.
- It does not require any costly equipment for weld small pieces.
- It can weld both similar and dissimilar metals.
- Properties of the weld joint are similar to the base material.
- No filler material required.
Disadvantages:
- Only small objects can be weld. Larger objects required
large press and heating furnaces, which are not economical. - The high skill required because excessive hammering can damage
the welding plates. - High Welding defects involve.
- It cannot use mass production.
- Mostly suitable for iron and steel.
- It is a slow welding process.
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