The arc burns invisibly between a melting electrode and the work piece, or between two melting electrodes. Arc and welding zone are covered by a layer of flux. The weld pool is protected from the admission of the atmosphere by slag developed by the flux.
The shown cross-section shows that the weld pool is covered by the powder which results in a very good thermal operating ratio which is to be found in a high deposition efficiency wel-ding process.
During the submerged arc welding process there are metallurgic processes in the stage of drops, in the pool reaction and in the area of dilution with the base material.
The reaction in the drop stage and in the pool reaction are determined by a welding flux and the used welding filler.
There are influences of the welding filler and the base material in the area of the dilution. That shows that chemical combi-nations of the weld metal and its mechanic-technological characteristics extremely depend on the used wire-power-combination which always have to be related to the base material.
In the diagram deposition efficiency of conventional welding processes are compared.
When submerged arc welding the usual deposition efficiency with a wire electrode diameter of 4 mm is at 7 to 8 kg/h if the duty cycle is at 100 %.
From this point of view it can be concluded that this welding process has to be fully mechanised since when manual welding such deposition efficiencies do not lead to such high deposition efficiency.
It has also to be taken into consideration realise that sub-merged arc welding is a high-capacity process that normally can be used with a material thickness starting from 6 mm.
Furthermore, a very important area of usage is the cladding of materials in order to protect them from corrosion and/or tear. For cladding tasks usually the two wire submerged arc welding or the submerged-arc strip welding process are used since with both processes a drastic dilution decrease of the base material can be achieved.
According to the wide field of use, f. ex. container construction, shipbuilding and pipe construction, there is also a wide range of materials used.