A metal wire welding material used as a filler metal or both for conducting electricity during welding. In gas welding and tungsten gas shielded arc welding, the welding wire is used as a filler metal; In submerged arc welding, electroslag welding, and other consumable gas shielded arc welding, the welding wire is not only a filler metal, but also a conductive electrode. Welding wires can be divided into three categories. Below, Haochen Hot Runner provides a brief introduction to cast welding wires and flux cored welding wires.

Cast welding wire

Some alloys, such as cobalt chromium tungsten alloy, cannot be forged, rolled, or drawn, but are made by casting methods. It is mainly used for manual surfacing of workpiece surfaces to meet special performance requirements such as oxidation resistance, wear resistance, and corrosion resistance at high temperatures. Continuous casting and liquid extrusion can be used to produce several meters of cobalt chromium tungsten welding wire, which is used for automatic wire filling tungsten gas shielded arc welding to improve welding efficiency and weld layer quality, while also improving labor conditions. Cast iron repair welding sometimes also uses cast welding wire.

Flux cored welding wire

A thin steel strip is rolled into a circular or irregular steel pipe, filled with a certain amount of powder, and then pulled to form a seamless flux cored welding wire, or a seamless flux cored welding wire is drawn with the steel pipe filled with powder (see figure). Using this type of welding wire for welding and deposition has high efficiency, good adaptability to steel, and short trial production cycle, thus its usage and scope are continuously expanding. This type of welding wire is mainly used for carbon dioxide gas shielded welding, submerged arc welding, and electroslag welding. The composition of the powder in the flux cored welding wire is generally similar to that of the electrode coating. Flux cored welding wire containing slag making, gas making, and arc stabilizing components does not require protective gas during welding, and is called self-protection flux cored welding wire, suitable for the construction of large-scale welding structural engineering.

As early as the early 1950s, gas shielded flux cored welding wires were developed and marketed, but it was not until 1957 that they began to be widely used commercially. This method can be said to be a combination of the advantages of submerged arc welding and CO2 welding (referring to solid). The welding flux is wrapped in the welding wire and protected by external CO2 gas, which can produce a softer and stable arc and low splashing during welding. At the beginning of development, there were only large wire diameter welding wires (2.0-4.0mm) used for flat and horizontal welding of major workpieces. It was not until 1972 that the development of small wire diameter welding wires greatly expanded the field of use of flux cored welding wires.

Self shielded flux cored welding wire was developed shortly after the introduction of gas shielded flux cored welding wire and was quickly recognized by the industry for specific purposes.