The welding Process refers to the method of joining metal parts together by the use of heat/pressure or both. Several welding and brazing processes are being applied by industries along with the soldering process and may be classified on the source of energy, or on the type of interaction.
Source of energy used by welding
Various types of sources are used for joining metal together, commonly used sources of energy are listed below:
- Fuel (flammable gas)
- Electric arc
- Chemical reactions
The welding processes may be classified on behalf of the above-mentioned energy sources.
Fuel gases are the most versatile method used for the purpose of welding. Probably it is the first kind of energy source that is used for welding metals. Gas welding can be classified upon its uses of flammable gas types such as :
Gas welding process
- Air-acetylene Welding
- Oxyhydrogen welding
- Oxyacetylene welding,
- Pressure gas welding
The second source is” Electric arc” which is the most commonly used in the modern era, for the joining of metals. Various welding methods are being operated by using electricity, which is called the arc welding process.
Arc welding process
- CAW- Carbon arc welding
- FCAW- Flux-cored arc welding
- GTAW- ( tig)Gas tungsten arc welding
- PAW -Plasma arc welding
- SMAW- Shielded metal arc welding
- GMAW-(MIG)Gas metal arc welding
- SAW -Submerged Arc welding
- ASW -Arc Spot Welding and
- SW -Stud Arc Welding, etc.
Above mentioned arc processes are used an electric arc to obtain the required heat, some of these are automatic, some are semi-auto and some are hard to operate manually.
Apart from these some processes use electric power sources for heat generation in other ways, like creating an electrical resistance to obtain the desired heat. These methods fall under resistance welding.
Resistance welding process
- Seam welding
- Spot welding
- Projection welding
- Resistance butt welding
- Percussion welding
- High-frequency resistance welding
- Flash butt welding
The use of the Laser as a ” power source” is a modern invention as compared to the above-mentioned processes, these methods are as follows:
Radiant energy welding process
Electron Beam welding process
Laser Beam welding process
Some of the processes are being operated by exothermic reactions to obtain the desired heat, that type of process is considered a thermochemical welding process.
Thermochemical welding process
- The atomic hydrogen welding process
- Thermit welding process
Some of the welding processes are used pressure to weld metals, and in these processes, the temperature is almost lower than the melting point of the base metal like:
Solid-state welding process
- Cold welding,·
- Diffusion welding(Bonding),·
- Ultrasonic welding,
- Explosive welding,
- Friction welding and Inertia welding
- Forge welding
Commonly welded base metals
Metals can be classified as ferrous materials or non-ferrous materials
Ferrous materials are the most important metals/alloys in the metallurgical and mechanical industries because of their very extensive use. The most common ferrous metals are as follows:
- Wrought iron
- Cast iron
- Carbon steel
- Stainless steels
- Alloy steels etc.
Those materials that are not iron-based are called non-ferrous materials such as :
- Aluminum and its alloys
- Copper and its alloys
- Nickel and its alloys
- Zink and its alloys
- Magnesium and its alloys
Welding has now become an essential part of our lives and is extensively applied in manufacturing sectors, it is beneficial to repair and maintain broken parts and rebuild worn-out components also.
Welding applications can join a variety of materials without altering their properties. Due to the flexibility, speed, and easy techniques, most welding processes can be used in the industrial field.
Services including electrodes, shielding gases, and components are available in all-region. Welding permits considerable freedom in design. filler wire, stick electrode, and flux are almost inexpensive and available as per the composition of base materials. all types of joint
Welds transfer harmful radiations such as light, fumes, and slag that can lead to health problems. Argon,carbon-di-oxide, or other shielding gases reduced the level of oxygen, and produce a difficult (inert) environment for breathing.
The fusion welding process is typically melting the base materials, thus the welders or technicians required extra care against the fire and burning hazards.