ABSTRACT
There are different types of welding processes for different applications. In the arc welding processes which are the common type of fusion welding processes, the energy for coalescence is provided by the arc. The intense heat generated by the arc results in near instantaneous melting of the base metal, and the metallurgical bond is created between the abutting members after the solidification of the melted region. The heat liberated in the arc can be calculated as the product of process efficiency, the welding current and the voltage. The current decides the metal deposition rate and the extent of penetration in the base metal while the width of the weld metal is decided by the voltage. The process efficiency lies in a range, and the exact value has to be selected for a given welding condition. The salient features of the different arc welding processes must be understood for selecting the appropriate welding parameters.
