Submerged Arc Welding Working, Advantages

Submerged Arc  welding operation

  

Submerged arc welding

Submerged Arc Welding Working, Advantages  It is an arc welding process wherein coalescence is produced by heating with an electric arc. The arc, end of the electrode, and molten pool remain completely hidden and are invisible being submerged under a blank of granular material (flux).

What is Submerged Arc  Welding 

Submerged arc welding formation of an arc between a continuously feed base wire electrode and the w/p. The process uses a flux to generate protective gas and slag. The arc moves along the joint line and excess flux is recycled via hooper. The electrode is mostly a solid wire but latelyconed wires have been introduced. To increase productivity an arrangement with several electrodes can be introduced. Because of its high metal deposition rate, it is particularly suited to the long straight joints of good quality in a flat portion.

Submerged Arc  Welding Construction 

Fig. shows a layout of submerged arc welding. It consists of a welding head. It feeds flux and filler metal to the welding joint and the electrode gets energized here. A flux hopper stores the flux and controls the rate of flux deposition on the welding joint. An AC transformer or a DC generator rated unto 1500 Amps may be used for submerged arc welding. A granulated flux shields and thus protects the molten weld metal from atmospheric contamination. The electrode composition depends upon the material being welded.

Submerged Arc  Welding Working

The trigger is pulled and the flux starts depositing on the joint to be welded since the flux when cold is a nonconductor of electricity, the arc may be strict either by touching the electrode with the job before switching on the welding current.
The arc is struck under a cover of flux.
Flux otherwise is an insulator but once it melts due to the heat of the arc, it becomes highly conductive and hence the current flow is maintained between the electrode and the job through the molten flux.

The electrode at a predetermined speed is continuously fed to the joint to be welded. The arc length is kept constant by using the principle of a self-adjusting arc.

Submerged Arc  Welding Advantage

1)    Molten flux provides very suitable conditions for high current flow.
2)    Because of high heat concentration, a considerably higher welding speed can be used.
3)    Because of high heat concentration and faster welding speeds, weld distortion is much less.
4)    A high metal deposition rate can be achieved.
5)    Welding is carried out without sparks smoke, flash.
6)    Very neat appearance and smooth weld shape can be got.

Submerged Arc  Welding Disadvantage

1)    Since the operator can not see the welding being carried out, he cannot judge accurately the process of welding.
2)    Flux needs preplacing of the same on the joint which is not always possible.
3)    The process is limited to welding in a flat position and on metal more than 4-8mm thick.
4)    The process requires edge preparation and accurate fit upon the joint.
5)    Flux is subjected to the contamination that may cause weld porosity.

Submerged Arc  Welding Application

1)    Fabrication of pipe, Pressure vessels, boilers, etc.
2)    Automotive, Aviation, Ship-building industry.
3)    Rebuilding of worn-out parts and depositing wear-resistance alloys.
4)    For welding metals like mild steel, medium, and high tensile steel.