Welding is the process that is used to joint materials, mostly thermoplastics or metals, by coalescence. It is a potentially hazardous process and should be carried out with precautionary steps to avoid electric shock, inhalation of poisonous fumes and gases, burns, vision damage and exposure to intense ultraviolet radiation.
Till the 19th century
Until the end of the 19th century, forge was the only welding process to be used. Blacksmiths used this technique for centuries to join steel and iron by heating and hammering. Later in the same century, oxyfuel technique and arc technique were developed. Electric resistance process were to follow soon after.
In the 20th century
Technology advanced significantly and rapidly in the early part of the 20th century, with the World War I and II demanding inexpensive and quicker methods of joining things. Following the wars, several techniques developed, including shielded metal arc process that is now one of the most commonly used techniques.
Other techniques which developed were gas metal arc technique, flux- cored arc technique, submerged arc technique and electroslag technique. Laser beam, electromagnetic pulse, friction stir, electron beam were to follow in the latter half of the century.
The scenario today
Science still continues to advance. Today, robot welding is common in industrial settings and researchers continue to develop newer and more advanced techniques.
Power supplies
A number of different power supplies are used for the welding process, the most common being constant power supplies and constant voltage supplies. The type of current used also has an impact on the process. Other sources of energy used are gas flame, laser, friction, electric arc, electron beam and ultrasound.
Unusual conditions
While most processes are done in controlled conditions like in repair shops and factories, some processes are also carries on in some rather unusual conditions, like in space, underwater and open air. For open air condition, shielded metal arc technique is the process commonly used. The process is also often used in under- water conditions, like in the construction and repair of ships, pipelines and offshore platforms. In space, the process was first attempted by Russian cosmonauts in 1969. Advances in this field can be helpful in future endeavors like construction of International Space Station.
Safety issues
Welding can be dangerous and unhealthy if the right safety precautions are not undertaken. However with the use of safety measures and advanced technologies, fatal accidents can be prevented. Welders should wear personal protective equipments in the form of protective long sleeve jackets and heavy leather gloves to avoid exposure to extreme heat and flame.
The excessive brightness of the weld area can lead to a condition known as flash burns or arc eye in which ultraviolet light causes inflammation of cornea and can cause the retina to burn. Safety helmets and goggles with dark UV filtering face plates are the solution.
If you are a resident of Edmonton looking forward to conduct a welding inspection service, there are many good companies to cater to your needs.
