What is the primary method of heat generation in SMAW?

In Shielded Metal Arc Welding (SMAW), the primary method of heat generation is through the electric arc. When an electric current passes through the electrode and creates a gap, an arc forms between the electrode and the workpiece. This electric arc generates intense heat, often exceeding temperatures of 6,500 degrees Fahrenheit (3,600 degrees Celsius), which is necessary to melt both the electrode and the base metal.

This method of heat generation is pivotal because it allows for effective melting and fusion of the materials being welded together. The electric arc not only provides heat but also facilitates the ionization of the surrounding air, creating a protective shield that helps prevent contamination of the weld pool. Other methods of heat generation, such as convection and radiation, do not produce the localized high temperatures required for welding. Similarly, friction, although it generates heat, is not utilized in the SMAW process, making the electric arc the essential and defining method in this context.