Welding

Welding: usually refers to the welding of metals. It is a forming method that uses heating or pressure, or both, to make two separated objects produce interatomic bonding forces and connect them into one.

Classification: According to the degree of heating and process characteristics during the welding process, welding methods can be divided into three categories.

(1) Fusion welding. The welding part of the workpiece is locally heated to a molten state to form a molten pool (usually with the addition of filler metal), which is cooled and crystallized to form a weld, and the welded workpieces are combined into an inseparable whole. Common fusion welding methods include gas welding, arc welding, electroslag welding, plasma arc welding, electron beam welding, laser welding, etc.

(2) Pressure welding. Whether heating or not, the welding process requires pressure welding. Common pressure welding includes resistance welding, friction welding, cold pressure welding, diffusion welding, explosion welding, etc.

(3) Brazing. The brazing filler metal (filler metal) with a melting point lower than the metal to be welded is melted, fills the joint gap, and diffuses with the metal to be welded to achieve connection. During the brazing process, the workpieces to be welded do not melt and generally do not have plastic deformation.