Arc welding

There are two categories: shielded metal arc welding (SMAW) and submerged arc welding (SAW). Shielded metal arc welding is common and it’s a manual welding method. This method is employed for joining shapes which are difficult to weld using ordinary welding methods. Here a solid electrode with an extruded backed-on-coating material is used. The arc is produced by short circuiting the electrode with the work piece. Depending upon the nature of the electrode, its dimensions and work to be done, welding current can be fixed. Electrode is coated with a flux material. This flux removes the impurities from the molten metal. Burning of electrode is faster than flux, which forms a crucible. This crucible shields the arc from atmosphere. In submerged arc welding, the heat required to fuse the metal is produced with the help of the electric current passing through welding wire and work piece. A layer of granular flux is used to cover the tip of the welding wire, weld area and the arc. A hopper-feeding mechanism and a conveyer tube are also used here for the fine treatment of weld spot, flux and arc. Here weld quality and finishing are superlative compared to other welding methods.