Shielded Metal Arc Welding Process:

Shielded Metal Arc Welding (SMAW) is arc welding procedure in which coalescence of metals is generated by heat from an arc that is maintained among the tip of a covered electrode and the surface of the base metal in the joint being welded.

The core of the covered electrode contains either a solid metal rod of drawn or cast material or one fabricated by encasing metal powders in a metallic sheath. The core rod conducts electric current to the arc and provides filler metal for the joint. The main functions of the electrode covering are to provide arc stability and to shield the molten metal from the atmosphere with gases formed as the coating decomposes from the heat of the arc.

The shielding employed, along other ingredients in the covering and the core wire, highly controls chemical composition, the mechanical properties, and metallurgical structure of the weld metal, along with the arc characteristics of the electrode. The composition of the electrode covering is differ according to the type of electrode.