Welding: also known as the melt, Jae Yong is a heating, high temperature or pressure bonding of hot metal or other plastic materials such as plastic manufacturing processes and technology. Welding through the following three ways to achieve the purpose of bonding:

　　1, heating to engage the workpiece to the local melting of the formation of molten pool, the pool cooling and solidification will be engaged, when necessary, can be added to melt filling material auxiliary

　　2, the melting point of the lower temperature of the solder, no need to melt the workpiece itself, by the capillary action of the solder connection of the workpiece (such as solder paste, solder paste)

　　3, in a to or lower than the melting point of the workpiece temperature combined with high pressure, laminated extruded or vibration make between two workpiece mutual penetration bonding (such as forging and welding, solid state welding)

　　According to the specific welding process and welding can be subdivided into gas welding, resistance welding, arc welding, induction welding and laser welding and other special welding.

　　There are many kinds of energy sources, including gas flame, arc, laser, electron beam, friction and ultrasonic wave. In addition to the use of the plant, welding can also be carried out in a variety of environments, such as the field, underwater and space. In any place, welding may bring danger to the operator, so it is necessary to take appropriate measures to protect the welding. Welding to the human body may cause damage, including burns, electric shock, visual damage, inhalation of toxic gases, ultraviolet radiation, etc., so in the welding time to have protective measures.

　　In the development of welding technology, welding machine also obtained the very big development, from the original welding machine to the present the latest technology of welding machine, the welding performance is greatly improved, calculus unit and calculation speed also increased a lot,