Welding is one of the most common machining processes. It is the process of applying heat to melt and fuse different metals. There are different types of welding machines and techniques used to achieve the intended results. Below are a few of the most commonly used welding machines.
As the name implies, this process uses an electric arc to generate heat and melt metals in order to join them together. An electrode is used to bring the electric arc in between the two metals.
The electric arc is capable of generating very high-temperature levels of above 3500 degrees celsius which can even melt high strength metals. While using this method, it is mandatory to use a shielding gas to prevent the reaction of molten metal with atmospheric air and cause oxidation.
Applications of Arc Welding
- It is used in construction sites to create sustainable infrastructure such as bridges with high tensile strength.
- It is used to bond components like switchboards, attach circuit boards, and fix fascia panels.
- It is used to weld metal furniture including cabinets and office desks.
- It is used to weld hatches, fluid lines, control panels, and other components in the shipbuilding industry.
Advantages of Arc Welding
- Arc welding is ideal for fusing high strength metals.
- The metals can be welded quickly due to a large amount of heat generated.
- The equipment can operate on both alternating current and direct current.
- The whole apparatus is compact and simple.
- The equipment is portable and you can weld the metals in a different place and then take it to the site.
Disadvantages of Arc Welding
- The arc welding process cannot be used to fuse thin metals.
- It cannot be used to weld reactive materials.
- You need a considerable level of skill to operate the welding equipment.
Metal Inert Gas Welding (MIG)
Similar to arc welding, this process also uses an electric arc to melt and fuse the metals. However, in this technique, the electrode also melts when it comes close to the melted region. As a result, the electrode is completely consumed during this process.
The melted electrode acts as a filler and helps to fuse materials having different properties. Shielding gas is used to prevent reactions between the fused metal region and atmospheric air.
Applications of MIG Welding
- It is used most commonly to weld different types of sheet metals.
- It is used to fabricate pressure vessels and steel structures.
- It is used in the home improvement and automotive industry.
Advantages of MIG Welding
- The main advantage is that it can be used to weld dissimilar metals.
- It can create high quality welded metals.
- The weld spatter is very less.
- The welding process can be automatic or semi-automatic.
- The welding process time is very less.
Disadvantages of MIG Welding
- You have to weld the metals only on the worksite. You can not weld outside and take it to the site.
- It is difficult to weld thick metals.
- You will have to prepare the metals before welding them together.
Tungsten Inert Gas Welding
Also known as Gas Tungsten Arc Welding, this process welds metals together using a non-consumable tungsten electrode. The tungsten electrode does not melt and remains intact at the end of the process.
This process uses inert gases for shielding the melted region. Argon is the most commonly used inert gas to achieve this. However, in some cases, a mixture of argon and helium is used to raise the temperature. This facilitates faster welding and higher metal penetration.
TIG welding can operate on both AC and DC. There should be no fluctuations in the current to avoid short-circuiting of the electrode. This welding technique is used to join non-ferrous metals namely, copper, aluminium, nickel, etc.
Applications of TIG Welding
- It is actively used in the construction of aircraft and in the aerospace industry.
- It is used to repair and restore worn-out body parts of automobiles.
- It is used in the automotive industry.
Advantages of TIG Welding
- It creates precise and strong welds.
- It produces high corrosion resistant and ductile joints.
- It does not require flux to shield the melted region.
- It can be automated or done manually.
- It can be done without using a filler material to fuse the metals.
Disadvantages of TIG Welding
- It is a very time-consuming process.
- It can only be used for welding thin metals.
- It needs a considerable level of skill to handle the equipment.
Flux Cored Arc Welding (FCAW)
Flux-cored arc welding is of two types namely self-shielded and gas-shielded flux-cored welding.
As the name implies, self-shielded flux-cored arc welding does not require any gas as a shielding agent. The shielding is obtained from the flux that generates gas to act as a shielding agent.
In the gas shielded flux cored welding, the flux produces only and gas is passed externally to shield the molten weld. Carbon dioxide is generally used as the shielding agent. The welding operator can control the quantity of shielding gas used in this case.
Both the techniques use a consumable electrode which melts and fuses with the two metals completely during the process.
Applications of Flux Cored Arc Welding
- It is used to weld parts in manufacturing plants.
- It is used in the shipbuilding industry.
- It is used in welding railroads.
- It is used in welding industrial piping joints.
Advantages of Flux Cored Arc Welding
- It has a high deposition rate.
- It can weld thicker metals
- It does not need any external gas shielding to prevent the reaction of molten metal with atmospheric air.
- There is no need to clean the metal before welding.
Disadvantages of Flux Cored Arc Welding
- The process releases high levels of fumes.
- The equipment used in this welding process is more expensive.
- Slag is deposited on the weld and must be removed.
Gas Welding – Oxyacetylene Welding
In this process, heat is generated from a concentrated that is used to melt and join metals together. The filler metal may or may not be added during the process.
Generally, oxygen and acetylene gas are used to fuel the flame. They are released to the welding torch from an oxygen gas canister and a fuel gas canister. By controlling the amount of gas fed to the flame, the temperature can be maintained.
In some cases, other fuel gases such as hydrogen, butane, and propane are used instead of acetylene.
Applications of Gas Welding – Oxyacetylene Welding
- It is used to fabricate sheet metals.
- It is used in the aircraft and automobile industries.
- It is used to join thin metals.
- It is used to join ferrous and non-ferrous metals.
Advantages of Gas Welding – Oxyacetylene Welding
- The welding equipment is portable and can be moved from one place to another.
- The equipment is affordable.
- The flame can be controlled and heat can be maintained easily using the welding torch.
- It is also used for gas cutting.
Disadvantages of Gas Welding – Oxyacetylene Welding
- It is not suitable to weld thin metals.
- It produces less heat than arc welding.
- It can not be used to weld reactive metals.
Welding finds its applications in a large number of areas including automotive, construction, electrical, and shipbuilding industries. The distinct features of each type help to meet the diverse needs of the industries. Based on your intended use, selecting the right welding machine will get you the job done.
If you have any doubts or queries, please share them in the comment section and we will be glad to help you out.