FCAWThe Flux Cored Arc Welding (FCAW) process is a variant of the MIG process and offers the potential for improved productivity and quality. It uses the heat generated by an arc struck between a continuously fed consumable filler wire and the workpiece to fuse the metal in the joint area. The consumable wire used in FCAW is of tubular construction and contains a core of flux and metal powder. In most cases, an additional shielding gas is provided to protect the arc and weld area, but gases generated by decomposition of the flux may be used instead. The main features of the process are high deposition rates, good weld fusion, alloying from the flux, weld metal support and shielding from the slag, and improved arc stability. The process is applied to welding a range of carbon and carbon-manganese steels, alloy steels and stainless steels. As well as welding, the process may also be used for surfacing and hardfacing. The filler wires are of three types, rutile, basic or self-shielded. Rutile, gas shielded, wires are easy to use with good slag removal and positional capabilities. Basic, gas shielded, wires give better mechanical properties, but tend to be less user-friendly and slag removal can be difficult. Self-shielded wires are ideal for site work but suffer in terms of operability and deposition rate due to the dual functions required of the flux. Shielding gases are either CO2 or argon-CO2 mixtures, with or without oxygen. The main drawbacks of the process are the cost of the wires and the amount of particulate fume they can generate.
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