How to Define Welding, Types, Limitations & Test after Welding

Welding & Types 

How to define Welding?

Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, forming a permanent bond.

What are the types of welding?

There are many types of welding, including:

1. Shielded metal arc welding (SMAW)
2. Gas metal arc welding (GMAW)
3. Flux-cored arc welding (FCAW)
4. Gas tungsten arc welding (GTAW)
5. Submerged arc welding (SAW)
6. Electroslag welding (ESW)
7. Plasma arc welding (PAW)
8. Resistance welding
9. Spot welding
10. Projection welding

Each type of welding has its own set of characteristics and is used for specific applications.

What are the Limitation of Welding?

There are several limitations of welding, including:

1. Material limitations: Not all materials can be welded, and some require special techniques or filler materials.
2. Weldability: Some materials are more difficult to weld than others due to their physical properties, such as high corrosion resistance or low thermal conductivity.
3. Weld size: The size of the weld is limited by the equipment and the welder's skill.
4. Weld strength: Welds may not be as strong as the base metal, and the strength of the weld may decrease over time due to the effects of aging or exposure to the environment.
5. Distortion: Welding can cause the materials to deform or become distorted, which can affect the dimensional accuracy of the final product.
6. Weld cracking: Welds can crack during or after the welding process, which can compromise the strength and reliability of the joint.
7. Safety: Welding can be dangerous due to the risk of fire, explosion, and exposure to harmful fumes and radiant energy.

What are the test required after welding?

After welding, various tests may be performed to ensure the quality and integrity of the welded joint, including:

1. Visual inspection: A visual examination of the welded joint to check for any cracks, porosity, or other defects.
2. Dye penetrant test: A non-destructive testing method that involves applying a visible dye to the surface of the weld and then removing any excess dye to reveal any cracks or surface discontinuities.
3. Magnetic particle test: A non-destructive testing method that uses a magnetic field and iron oxide or iron oxide-coated magnetic particles to detect surface and slightly subsurface discontinuities in ferromagnetic materials.
4. Ultrasonic testing: A non-destructive testing method that uses high-frequency sound waves to detect internal defects or measure the thickness of a material.
5. Radiographic testing: A non-destructive testing method that uses X-rays or gamma rays to produce an image of the internal structure of a material and detect any internal defects.
6. Tensile testing: A destructive testing method that measures the strength and ductility of a material by subjecting it to a tensile load until it breaks.
7. Bend testing: A destructive testing method that measures the ductility of a material by bending it to a specific angle and checking for any cracks or other defects.