Welding - technological process of receiving one-peace connection of details, as a result of local or general heating of the connected parts. As a result of welding of metal during the heating and/or pressure there are processes which create a continuity of the connected metals. On types the welding works are divided into the following types: manual welding, mechanized welding, automatic welding.
For production of metal welding are used various power sources: electric arch, gas flame, laser radiation, electronic beam, ultrasound.
Physical signs, depending on a form of the energy used for formation of welded connection are subdivided into three classes: thermal, thermomechanical, mechanical.