Some alloys, such as cobalt-chromium-tungsten alloys, cannot be forged, rolled, and wire-shaped, but are made with casting methods. It is mainly used for manual surfacing of workpiece surface to meet special performance requirements such as anti-oxidation, abrasion resistance and corrosion resisting at high temperature. The use of continuous pouring and liquid extrusion can produce a number of meters of cobalt-chromium-tungsten welding wire for automatic tungsten electrode gas shielded arc welding, in order to improve welding efficiency and the quality of surfacing layer, but also improve working conditions. Cast iron welding wire is sometimes used to repair.