MCAWThe Metal Cored Arc Welding (MCAW) 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 MCAW is of tubular construction and contains a core of iron powder and metal alloys but very little fluxing agent. An additional shielding gas is required to protect the arc and weld area in the same manner as that used for MIG. The main features of the process are good weld profile, good fusion, alloying additions from the core, and improved arc stability. The process is applied mainly to welding carbon, carbon-manganese and alloy steels, and may also be used for welding some stainless steel grades. The process is versatile and manufacturers can adjust wire formulations to suit different steels. Shielding gases are either CO2 or argon-20%CO2 mixtures, with or without oxygen. The main drawbacks of the process are the cost of the wires and the amount of welding fume they can generate.
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