Introduction
Welding is a process for joining two similar or dissimilar metals by fusion, with or without the application of pressure and with or without the use of filler metal. The fusion of metal takes place by means of heat. The heat may be generated either from an electric arc, electric resistance, combustion of gases, or chemical reaction.
Shielded Metal Arc Welding (SMAW) is an arc welding process in which the fusing of metals is produced by heat from an electric arc that is maintained between the tip of a consumable-covered electrode and the surface of the base metal in the joint being welded.
Shielded Metal Arc welding is one of the most widely used welding processes, particularly for short welds in production, maintenance, and repair work and for field construction.
This module will give every trainee a basic understanding of the SMAW process and equipment, along with the key variables that affect the quality of welds, such as electrode selection, polarity and amperage, arc length, travel speed, and electrode angles. We will also cover core competencies such as setting up welding equipment, preparing weld materials and fitting up weld materials, and repairing welds.
Some metals are easier to weld than others. To compare this ease in welding, the term 'weldability' is often used. The weldability may be defined as the property of a metal that indicates the ease with which it can be welded with other similar or dissimilar metals. The weldability of a material depends upon various factors like the metallurgical changes that occur due to welding, changes in hardness in and around the weld, gas evolution and absorption, extent of oxidation, and the effect on the cracking tendency of the joint.