Welding is essentially a fabrication or rather a sculptural process employed to join materials. The materials joined in welding are usually thermoplastics and metals. The joining is done by causing fusion that’s distinct from the metal joining techniques which employ the use of low temperatures: soldering and brazing.
These two don’t melt the base metal. In welding, the base metal is melted and in addition to the melting, a filter material is normally used on the joint thus forming the weld pool (a pool comprising of molten material). This cools down on the surface being welded thus forming a joint that may end up being as strong as that base material you are working on. In conjunction with the heat, pressure may at times be used to produce the weld though not always the case.
A Simple Guide To The Various Types Of Welding
- Electro slag Welding (ESW): This is a highly productive and effective single pass welding technique that is employed on thicker materials. It is the best method for welding materials that are between 800 mm (12 inches) and 25 mm (1 inch) in a close to vertical or vertical position.
- Submerged arc Welding (SAW): This welding method employs the use of a consumable electrode that is automatically fed and the use of a granular fusible flux blanket. The arc zones together with the molten weld are submerged under the granular fusible flax blanket to protect them from any form of atmospheric contamination.
- Shielded Metal arc welding (SMAW): This is also referred to as the “electric welding or the stick welding.” It employs the use of an electrode, which has flux (the puddle protecting material) around it. The electrode holder holds the electrode as it slowly melts and forms the joint. The weld puddle is protected from and atmospheric contamination by slag.
- Flux-cored arc welding (FCAW): This is somewhat identical to the MIG welding save for the fact that it employs the use of flux filled tubular wire. The use of a shielding gas is possible though optional and is dependent on the filler.
- Gas tungsten arc welding (GTAW): This is also referred to as TIG (tungsten, inert gas). It employs the use of electrodes that are non-consumable tungsten types in the production of a weld. An inert gas e.g. helium or argon is used for shielding thus protecting the weld area from any form of atmospheric contamination.
- Gas metal arc welding (GMAW): This is commonly referred to as MIG (metal, inert gas). It employs the use of a wire-feeding gun which is used to feed a wire at adjustable speeds. Argon based gas or a mix of carbon dioxide and argon is then flowed over the weld puddle thus offering a shield for protection against any form of atmospheric contamination.
Energy Sources and Safety
Numerous energy sources can be used in the different methods of welding. These include an electric arc, a gas flame, an electron beam, a laser, ultrasound and friction among others. The welding process can be done under diverse environments such as in open air, in the outer space and under water.
The welding process is known to be a very hazardous undertaking thus precautions have to be observed so as to avoid electric shocks, burns, cuts, inhalation of toxic fumes and gases, expose to intense Ultra Violet rays and radiations and protecting oneself from vision damage.
A Short History of Welding
The welding industry has really undergone a noticeable revolution within a very short space of time. Till the end of the nineteenth century, forge welding that was used by blacksmiths was the only present welding process. This had been used by blacksmiths for millennia by the blacksmiths to join steel and/iron by intensive heating and hammering. Later on in the century, oxyfuel welding and the arc welding became some of the very first welding methods to develop. Soon after, the electrical resistance method followed. The twentieth century saw an era of serious revolution as the welding industry saw intense development.
During the time of the world war I and the proceeding world war II, the need for quick, inexpensive and reliable joining methods saw the improvement of this technology. As a result, several other popular methods together with automatic and semi-automatic processes which include: Electro slag Welding (ESW), submerged arc Welding (SAW), Shielded Metal arc welding (SMAW), Flux-cored arc welding (FCAW), Gas tungsten arc welding (GTAW) and Gas metal arc welding (GMAW) came up.
Developments saw another turn when the invention of magnetic pulse welding, electron beam welding, laser beam welding together with friction stir welding were developed during the last half of the twentieth century. Today, the science has advanced so much that robotic welding is gaining more popularity in industrial set ups with researches still on toes trying to come up with better, more efficient and reliable welding methods.