What is Welding Process?
Welding is a joining process for metals in which two or more workpiece are joined with the help of extra material (or filler material).
Welding of workpiece leads to a permanent joint of that workpiece.
The strength of the welded joint can be as high as that of the base metal or parent material used for joining.
Welding is a complex process which involves;
- Heat and liquid metal transfer,
- Chemical reactions,
- Gradual formation of welded joint through liquid metal deposition and cooling of liquid metal to the solid state,
- Metallurgical transformation of material, etc.
The perfect weld is a weld in which there is continuity between the joined parts. And also, every part of the welded joint is homogeneous.
But practically it is very difficult to get the perfect homogeneous welded part because the microstructure and mechanical properties are not identical over the entire joint and the workpiece.
Having said that, let me tell you the advantages and disadvantages of welding process.
Advantages of Welding Process
The advantages of welding process are mentioned below.
- The welded joint obtained by welding process is a permanent type of joint.
- Welding equipments are not so expensive.
- The filler material is also as strong as the parent or base metal.
- By using the welding process, it becomes easy to join the complicated structure.
- Dissimilar metal can also be joined using a welding process.
- Welded joints offer pressure tight and air tight joints (except spot welding).
Disadvantages of Welding Process
The applications of welding process are mentioned below.
- Harmful radiation lights, fumes and spatters are produced during the welding process.
- Distortion of the workpiece may occur due to welding process. Also the residual stresses remain in the final welded component.
- Sometimes jigs and fixtures are required to hold the parts which are needed to be welded.
- In order to weld the thick metals, proper edge preparation is necessary.
- Good welder is required to produce the perfect weld joints.
- Some metallurgical changes appear in the welded component because the weld material and the parent metal are not the same.
- Sometimes, heat treatment is also required to relieve the residual stress from the component.
Applications of Welding Process
Applications of the welding process are mentioned below.
Welding process has many applications in most of the manufacturing industries like home applications, mining equipments, boilers, furnaces, air conditioning units, and many more components uses welding as a metal joining process.
Common applications of welding process are listed below.
- Shipping industries
- Railway bridges
- Piping and piping industries
- Aircraft industries
- Fabrication of tanks and pressure vessels
- Nuclear and thermal power plants
- Automobile industries
- Building construction
Welding process is also used in repairing machine tools, jigs and fixtures, boilers, railway coaches, ship building, underwater construction, etc.