4. Explain the working principle of submerged arc welding and its merits and demerits.
Answers
Submerged Arc Welding, also known as SAW, is the process that involves the formation of an arc by electrodes. The arc then uses its electrical charge to pass through a welding wire and the work piece for the application. The difference between submerged arc welding and regular arc welding is that the welding wire, arc, and weld joint are covered by a layer of flux. The flux creates a pathway for the arc to travel through to the material that is being welded. The flux creates a shield for the molten material which prevents splatters and contamination.
SAW Advantages:
One of the top advantages of submerged arc welding is that it prevents hot materials from splattering and splashing onto workers. Another benefit is that the flux prevents high levels of radiation from being emitted into the air. Submerged arc welding does not require added pressure to weld because it is already generated by the electrode. This application is excellent for quickly welding together thin metal sheets and creates a secure fusion between welds. This application also produces high productivity, fast travel speed, high repeatability, and quality results.
SAW Disadvantages:
Like most applications there are some limitations to submerged arc welding. One is that materials that can be welded by SAW are limited to steel, stainless steel, and some nickel. Submerged arc welding is also limited to materials that are long and straight or are rotated pipes. And despite having some safety advantages there is still the risk of having the residue from the flux left behind, which could be harmful to employee health.