(SAW) Submerged Arc Welding...

Submerged arc welding (SAW) is a high quality, high speed and high deposition rate welding method. It is generally used to join plates of small to very high thickness. There is semiautomatic and fully automatic welding process is possible.

Submerged arc welding set up:

First of all select the material to be welded. Prepare your welding joints and set it on the welding platform for welding. Selection of electrode size depends on the size of joints. Different variables like the speed of the electrode, power supply and type of material are required to set as per our requirements. Arc length should be kept constant so there is no problem of burn off metal.

In this method a bare electrode is used in the form of coil and its speed is set as per our speed of welding. Granular flux is provided in free form on the tip of electrode so arc is produced under the flux. The bead quality is very good and no problems of oxidation and contamination with atmosphere. Fusion of metal is also good.

It is used for straight joints and also for very large diameter pipe joints. For piping joints special attachments are required for moving of the job and flux feed. The SAW process operates on both AC and DC currents as well as constant voltage.

In submerged arc welding arc is produced between bare electrode and metal piece to be weld. The shielding of arc is provided by granular flux. Granular flux is feed automatically on the electrode tip as per requirement of welding and also depends on speed of welding. This welding is non- pressurized. Flux is feed by means of flux hopper provided at top so, flux is feed by gravity effect.

This flux also melts due to heat produced between the electrode and metal piece so it becomes lighter and it forms a layer on the weld bead. Arc is produced between the electrode and metal piece below the granular flux, so it is called SAW (submerged-arc-welding).

In the semiautomatic welding process, the speed of electrode is controlled by manually, when in fully automatic welding process the speed is set controlled by speed mechanism. In automatic SAW the electrode is travels on the fixed work piece joints or electrode is fixed and work piece is move below electrode.

It's used for carbon steel, low alloy steel, stainless steel and other metals. Basic requirement for submerged arc welding is material to be weld, then selection of electrode type to be used for given materials and other parameter likes speed of travel of the welding electrode, current and voltage.

An advantage of SAW is there is no contamination of the metal joint and no oxidation with atmosphere. The weld bead is more uniform than other welding processes. Speed and deposition rate is very high in SAW. Automation is possible in submerged arc welding, so it is mostly used in industries having mass production. In this process there is no spattering of metal on work piece.