For welding with pressure is contact welding, which uses the heat released in contact welded parts during the passage of electric current. Distinguished point, butt, seam and embossed contact welding. The main methods of contact welding developed in the late xix century. In 1887, nn Benardos received a patent for methods of spot and seam welding between carbon electrodes. Later, when the electrodes are made of copper and its alloys, these methods of welding steel core. Resistance welding is the leading mechanized welding methods in the automotive industry in the sheet-molded compound body structure car. Butt-welded joints connecting rails, joints of pipelines. Seam welding is used in the manufacture of thin-walled vessels.
Projection welding – the most high- method of welding fittings for the construction of reinforced concrete structures. Capacitor resistance welding is widely used in electronic industry in the manufacture of components and chips. One of the most developing trends in the welding industry – wide use of mechanized and automatic welding. It is as mechanization and automation of welding processes themselves (ie, the transition from manual labor welder to mechanized), and a comprehensive mechanization and automation, encompassing all activities associated with the manufacture of welded structures (procurement, assembly, etc.) and the establishment of stream and automatic production lines. With the development of technology there is a need welding of various thicknesses of different materials, in connection with the constantly expanding range of species and used welding methods. Today while the workpiece thickness from a few micrometers (in microelectronics) to tens of centimeters or even meters (heavy engineering). Along with the structural carbon and low alloy steels are increasingly have to weld special steels, light alloys and titanium-based alloys, molybdenum, chromium, zirconium and other metals, as well as dissimilar materials.