Welding:
Welding is a process by which two materials usually metals are permanently joined by coalascence ,which is induced by a combination of temperature ,preassure and metallurgical conditions.
Basic requirements
In welding process a permanent joint is made by coalascence.To obtain coalascence between two metals,formation of common metallic crystals is necessary.the ideal metallurgical bond requires:-
1) Perfectly smooth, flat (or) matching surfaces.
2) Metals without impurities. clean surfaces (no oxides and absorbed gases).
3) Identical crystallographic structure.
1) Perfectly smooth, flat (or) matching surfaces.
2) Metals without impurities. clean surfaces (no oxides and absorbed gases).
3) Identical crystallographic structure.
Welding classification:
The different types of welding are classified into two groups--
Fusion Welding are sub-divided into the bellow groups
i) Gas Welding
ii) Electric Arc Welding
iii) Thermit Welding
Pressure Welding or Plastic Welding is also sub-divided into following groups
1) Forge Welding 2) Electric Resistance Welding
- Fusion Welding
- Plastic Welding or Pressure Welding
Fusion Welding are sub-divided into the bellow groups
i) Gas Welding
ii) Electric Arc Welding
iii) Thermit Welding
Pressure Welding or Plastic Welding is also sub-divided into following groups