Classification Of Welding

Welding:- 

Welding is a process of joining two metallic components for the desired purpose, can be defined as the process of joining two similar or dissimilar metallic components with the application of heat, with or qithout the application of pressure and with or without use of filler metal,heat may be obtained by chemical reaction, electrical arc, electrical resistance, frictional heat, sound and light energy. If no filler metal is used during welding then it is termed as "Autogeneous welding process".

Welding processes can be classified on following criteria:

1. Welding with or without filler material

2. Source of energy of welding

3. Arc and non arc welding

4. Fusion and pressure welding

1. Welding can be carried out with or without the application of filler material. Earlier, only gas welding was the fusion process in which joining could be acheived wit or without fillar material. When welding was done without filler material it is called autogeneous welding. However, with the development if TIG, electron beam and other welding processes such classification created confusion as many processes shall be falling in both the categories.

2. Various sources of energies are used such as chemical, electrical, light, sound, mechanical energies but expect for chemical energy other forms of energies are generated from electrical energy for welding.

3. Arc and non arc welding classification embraces all the arc welding processes in one class and all other processes in another class. In such classifications it is difficult to assign either of the class to processes such as electoslag flux the arc extinguishes while in flash butt welding tiny arcs.

4. Fusion welding and pressure welding is most widely used classification as it covers all the processes in both categories irrespective of heat source and welding with or without filler material. In fusion welding all those processes are included where molten metal solidifies freely while in pressure welding molten metal if any is retained space under pressure. This type of classification poses no problems so it is considered as the best.