The welding wire is used as a filler metal or as a metal wire welding material for conducting electricity at the same time. In gas welding and gas tungsten arc welding, the welding wire is used as filler metal; In submerged arc welding, electroslag welding and other MIG welding, the welding wire is not only the filler metal, but also the conductive electrode. The surface of the welding wire is not coated with the anti oxidation flux.
Some alloys, such as cobalt chromium tungsten alloys, cannot be forged, rolled or drawn, but are made by casting. It is mainly used for manual surfacing of workpiece surface to meet special performance requirements such as oxidation resistance, wear resistance and corrosion resistance under high temperature. Cobalt chromium tungsten welding wire up to several meters can be manufactured by continuous pouring and liquid extrusion, which can be used for automatic wire filled tungsten gas shielded arc welding to improve welding efficiency and quality of surfacing layer, as well as improve working conditions. Cast wire is sometimes used for repair welding of cast iron.