Working : Shielded metal arc welding uses a metallic consumable electrode of a proper composition for generating arc between itself and the parent work piece. The molten electrode metal fills the weld gap and joins the work pieces. This is the most popular welding process capable to produce a great variety of welds. The electrodes are coated with a shielding flux of a suitable composition. The flux melts together with the electrode metallic core, forming a gas and a slag, shielding the arc and the weld pool. The flux cleans the metal surface, supplies some alloying elements to the weld, protects the molten metal from oxidation and stabilizes the arc. The slag is removed after Solidification.
Advantages
1. Simple , portable and inexpensive equipment
2. Suitable for outdoor applications
Disadvantages-
1. Process is discontinuous due to limited length of the electrode.
2. Weld may contain slag inclusions
3. Fumes make difficult the process control.