1. To study the submerged arc welding process.

2. To understand the effect of process parameters on the weld bead geometry and mechanical
    properties.

3. To understand the effect of process parameters on the weld bead geometry and mechanical
    properties.

4. To understand the effect of process parameters on the microstructural properties.

Submerged Arc Welding (SAW) is a fully automated high productive process. A bare electrode is continuously fed through contact tube connected to the power source. Wire feeding is done by a motor connected with the controller. Roller guide draws wire from a reel. The wire where it meets the work piece and surrounding area always remain covered with granular flux continuously fed from the flux hopper. The arc is generated when the electrode comes closer to the job piece. For this welding process DCEP i.e., electrode connected to positive terminal of the power source and job piece connected to negative is most preferred.

Due to flux covering the arc is not visible. Hence the name submerged arc applies. The heat generated, melts portion of the flux above the arc. This molten flux acts as a protective covering as well as thermal insulation during and after the welding process. The molten flux solidifies to form slag as the arc propagates along the weld line. After the welding is done, unused/unsolidified granular fluxes can be collected for reuse. The slag is removed by chipping. The flux also acts as a thermal insulator by promoting deep penetration of heat into the work piece. The unused flux can be recovered (using a recovery tube), treated, and reused. The consumable electrode is a coil of bare round wire 1.5 to 10 mm in diameter; it is fed automatically through a tube (welding gun). Electric currents typically range from 300 to 2000 A. The power supplies usually are connected to standard single- or three-phase power lines with a primary rating up to 440 V. Because the flux is gravity fed, the SAW process is limited largely to welds in a flat or horizontal position having a backup piece. Circular welds can be made on pipes and cylinders provided that they are rotated during welding.

Equipment Used

1. First check the power connections and polarity.

2. Fill the flux hoper with granular flux and check continuity of flux flow by opening the stopper.

3. Fit the electrode wire through the drive and guide roller.

4 Turn on the power and check travel and wire feed as well as mark the welding line.

5 Clamp the two pieces to be welded along the weld line.

6 Now set operating parameters on the control panel.

7 Release the flux stopper to cover the plates and electrode with fluxes.

8 Engage the auto travel lever and start the process.

9 Check for the sound of welding as a signal that welding is going on.

11 Collect the unused flux and then remove the solidified slag by chipping.