Others

There are some other types of welding process such as:

• Flux-cored arc welding (FCAW): almost identical to MIG welding except it uses a special tubular wire filled with flux; it can be used with or without shielding gas, depending on the filler. It is just a new type of an electrode that can be used on a MIG welding machine. Flux cored arc welding is a process similar to MIG welding. Both processes using continues wire feeds, and similar equipment. The power supply for a FCAW, and a MIG welder, are the same machine. They are both considered semi-automatic processes, and have a very high production rate. The main difference between flux cored arc welding and MIG welding is the way the electrode is shielded from the air. Flux cored arc welding just like the name implies, has a hollow wire with flux in the center, similar to the candy called "pixy sticks".
• Submerged arc welding (SAW): uses an automatically fed consumable electrode and a blanket of granular fusible flux. The molten weld and the arc zone are protected from atmospheric contamination by being "submerged" under the flux blanket. Similar to MIG welding, SAW involves formation of an arc between a continuously-fed bare wire electrode and the workpiece. The process uses a flux to generate protective gases and slag, and to add alloying elements to the weld pool. A shielding gas is not required. Prior to welding, a thin layer of flux powder is placed on the workpiece surface. The arc moves along the joint line and as it does so, excess flux is recycled via a hopper. Remaining fused slag layers can be easily removed after welding. As the arc is completely covered by the flux layer, heat loss is extremely low. This produces a thermal efficiency as high as 60% (compared with 25% for manual metal arc).
• Electroslag welding (ESW): a highly productive, single pass welding process for thicker materials between 25 mm and 300 mm in a vertical or close to vertical position. Electroslag Welding is a welding process, in which the heat is generated by an electric current passing between the consumable electrode (filler metal) and the work piece through a molten slag covering the weld surface. Prior to welding the gap between the two work pieces is filled with a welding flux. Electroslag Welding is initiated by an arc between the electrode and the work piece (or starting plate). Heat, generated by the arc, melts the fluxing powder and forms molten slag. The slag, having low electric conductivity, is maintained in liquid state due to heat produced by the electric current. Electroslag Welding is used mainly for steels.