According to the state of metal materials in the process of welding, welding methods can be divided into three categories: fusion welding, pressure welding and brazing.

1. Fusion welding: the welding method of melting the base metal to form a weld is called fusion welding. Common arc welding, gas welding, electroslag welding, submerged arc welding and various gas welding, laser welding.

1. The melting electrode and the non-melting electrode are divided into: the melting electrode includes electrode arc welding, flux cored wire arc welding (MAG), argon arc welding (MIG), gas shielded welding, etc.; The non-melting electrode includes TIG welding and plasma arc welding.

2, pressure welding: in the process of welding, it is necessary to apply pressure on the welding parts (heating or not heating), in order to complete the welding method, known as pressure welding.

1. There are resistance welding, pneumatic welding, high-frequency welding, forging welding, contact welding, friction welding, etc.;

2. Some methods of non-heating pressure welding include cold pressure welding, ultrasonic welding and explosion welding.

Brazing: it is the general term of hard brazing and soft brazing. It USES metal with lower melting point than the base metal as the filler material, heats the welding part and solder to a temperature higher than the melting point of the base metal and lower than the melting point of the base metal, wets the base metal with liquid solder, fills the joint gap and diffuses with the base metal to connect the welding part.

1, brazing: adopting the brazing alloy, solder melting temperature above 450 ℃;

2, soft soldering: using soft solder, solder melting point was below 450 ℃.

3. Common brazing methods include soldering iron brazing and flame brazing.