Specification of Electrodes
Generally, the size of the electrodes is specified by the length and its diameter. They are available to a maximum of 12 mm diameter and 450 mm length. The size of the electrode increases with the current used. In manual welding, the size of the electrode changes according to the thickness of the metal parts. Spring like electrodes are used in automatic welding.
Types of Electrodes
The electrodes used in arc welding are of two types
- Consumable electrode
- Non-consumable electrode
There are three types of consumable electrodes. They are
- Bare electrodes
- Lightly coated electrodes
- Heavily coated electrodes
Non-consumable electrodes are used in the processes of atomic hydrogen welding and TIG welding.
Selection of Electrodes
The material used for manufacturing electrodes depends upon the material to be welded. Given is the list indicating suitable materials for manufacturing electrodes for welding different metals.
|Sl. No.||Material to be welded||Electrode material|
|1.||Wrought iron||Low carbon steel|
|2.||Mild steel||Mild steel with copper coating|
|3.||Alloy steel||Nickel steel|
|4.||Cast iron||Cast iron|
|5.||Aluminium||Cast aluminium alloy|
|6.||Carbon steel||Steel wire(0.15% carbon & 0.025% Phosperous|