Welding wire is used as metal filling stuff or at the same time as metal wire welding materials for electric conduction. In gas welding and tungsten pole gas shielded arc welding, the welding wire is used as filling metal; in submerged arc welding, electroslag welding, and other melting pole gas shielded arc welding, the wire works both as filling metal also conductive electrodes. Welding wire can be divided into three categories. The wire surface does not require flux for anti- oxidation. 1.Rolled Welding Wire. Most welding wire falls into this category, including carbon steel wire, low-alloy steel wire, alloy structural steel wire, stainless steel wire and nonferrous metal wire, etc. 2.Casting Welded Wire. Some alloys, such as cobalt-chromium-tungsten alloy can not be made by forging, rolling, and drawing, can only be made by casting. Casting welding wire is mainly used for manual welding workpiece surface in order to meet special property requirements such as anti-oxidation, anti-wear and high temperature corrosion resistance, and other special performance requirements. Use of continuous casting and liquid extrusion can produce up to a few meters of cobalt chromium tungsten wire, tungsten wire for automatic filling gas shielded arc welding, in order to enhance welding efficiency and quality of cladding layer, while also improving the working conditions.