Submerged welding is an arc welding method where the heat necessary for the welding is generated by the arc(s) formed between a wasting electrode (or several electrodes) and the workpiece. The arc area welding powder layer as well as the welding metal and base metal close to the weld are protected by the melted welding powder (slag). In submerged welding the electricity flows through the arc and the welding bath formed melted metal and melted slag. The arc heat electrode forms the welding bath that fills up the welding bend by melting the melting powder and base metal The welding powder, which is a protective task, also reacts with the welding base and deoxidize the welding metal.The welding powders used for welding the alloy steels may contain alloy elements that compensate the chemical composition of welding metal. Submerged welding is an automatic welding method. In some submerged arc welding applications two or more electrodes may be fed the welding bend.Electrodes may be fed into in side-by-side (twin arc) welding bath or far enough to ensure that the weld baths are hardened independently from each other; thereby thereby a high welding speed and high metal accumulation speed may be obtained.
Benefits:
- It is a method with high welding speed and high metal accumlation speed which can be used in the welding of flat and cylindrical parts, tubes with all thicknesses and sizes for hardfacing welds
- It provides perfect and high mechanical strength welding seams.
- There is no spatter during arc welding and arc heat is not visible, therefore the welding operator needs less protection.
- It is possible to weld the weld angle bends in contrast to the other methods.
- 5. The submerged welding could be performed in both indoor and outdoor areas.
Disadvantages:
- The submerged welding powders are prone to gain moisture from the air, which is a cause of pores in welding.
- The base metal must be smooth and not be oil, rust and other contaminants on the base metal surface In order to obtain high quality welds.
- The spatter should be removed out of the weld seam and this may be difficult in some applications. In multi-pass welding works, the slag should be removed after each pass in order to avoiding slag residuals.
- The submerged welding method is not suitable for materials thinner than 5 mm because it may able to cause oxidation.
- The method is suitable for flat, horizontal butt-welding and corner welds, except for some special applications
- For each metal and alloy is not applicable method.