Welding – the process of obtaining non-detachable connections by establishing interatomic connections between the welded parts with their local or general heating, plastic deformation or joint action of both and the other .
An integral connection made by welding is called a welded joint . Most often, with the help of welding, connect the metal parts. However, welding is also used for non-metals – plastics, ceramics or their combination.
When welding different sources of energy are used: electric arc, electric current, gas flame, laser radiation, electronic beam, friction, ultrasound. The development of technologies allows welding at the present time not only in the conditions of industrial enterprises, but in field and installation conditions (in the steppe, in the field, in the open sea and so on), under water and even in space. The welding process is associated with the danger of fire; electric shock; poisoning with harmful gases; defeats of the eyes and other parts of the body by thermal, ultraviolet, infrared radiation and spills of molten metal.
Welding is feasible under the following conditions:
application of very high specific pressure of compression of parts, without heating;
heating and simultaneous compression of parts with moderate pressure;
heating the metal in the place of connection to the melt, without the use of pressure for compression.