The manual metal arc welding process to join the metal by using electric arc. Arc welding can be weld two metal by melting with an arc generated between electrode and base metal. Arc and power source consist for this diagram. In this manual metal arc welding process the positive pole of DC current is called as anode and negative terminal called as cathode. The arc should be generated between an anode (positive pole of DC current) and cathode (Negative pole of DC current) is connected to power source.
The electric arc is provided by touch the electrode on the base metals (work piece) and withdraw it short distance from work piece. When the work piece and electrode in contact, the current flow and they are separated the current continues to flow to the anode through the air in gap between the work and electrode. When the current flow ionizes the air, these ionized particles are electronic arc.
The ionized gas acts as high resistance conductor enable more ions to flow from the anode to cathode. The strikes of work piece, that is generated heat to the base metal gap that two conductors placed on a small distance (3mm).The current flow pass through the gaseous media, provide from of arc. That arc is change together, energy into heat and light. That arc welding process, 1 kwh of electricity generated 1000 J, the temperature at the arc is being 6000 to 7000⁰c.
The advantage of manual metal arc welding process than gas welding:
- High arc temperature
- Widely speed of weld operation
- Concentration of heat in small are can be welded
- Small amount of heat spread reduces bulking and wrap of work piece.
- The heat concentration will be increase the depth of penetration
- That is more economical than gas welding.
- Multiple of metal can be welded
- It control is simple and easy.