British Corewire company specializes in the research and development of self-protective flux-cored wires specifically designed for the repair of railway tracks, switches, and frogs. These wires feature high deposition rates and low cost. When used with a dedicated lightweight, mobile su***cing trolley, they are particularly suitable for the rapid maintenance of railway tracks, switches, and frogs. Since most track welding work must be completed during the idle periods between train passages, the time required for repair is a critical factor. Additionally, increasing deposition efficiency and improving economic benefits are also important considerations.
Defects in railway tracks can arise from various causes, such as track production processes and operational conditions. These defects manifest as inclusions, circular indentations, wheel burns, and pressure marks, among others, and must be repaired promptly. Strict control over the welding process is essential to ensure defect-free repairs and an efficient service life. Flux-cored wires reduce the number of weld passes and arc starts, thereby minimizing welding defects. Carbon-manganese rails are susceptible to air hardening, so careful control of preheating, interpass temperature, and cooling rates is necessary. Manganese alloy steel is sensitive to hot brittleness, so the interpass temperature must be strictly controlled; if the temperature exceeds 200°C, cracking can easily occur.
Application in Rail Repair
When repairing rails, the primary considerations are the speed of su***cing, ensuring no inclusions in the weld bead, and ****** operation. For railway repair, the operation process must be quick and effective, which is key to a successful repair. Corewire's rail repair welding materials are specialized products developed in collaboration with British and European railway authorities.
In the past, manual electrode arc welding, also known as self-shielded metal arc welding, was widely used for rail maintenance and repair. Now, a ******r, more versatile, and user-friendly method has emerged for su***cing ferritic base materials, which can meet all the requirements for rail repair. However, the need for repair speed arises because most rail repairs must be carried out during the intervals between train passages. Clearly, time is a very important factor. Therefore, we have developed a method that provides rapid su***cing while remaining as ****** and easy to operate as manual welding.
Corewire has developed two types of self-protective wires, BS11B and MN33. These wires themselves have high deposition rates, requiring less weld metal to improve economic efficiency. Fewer arc restarts reduce the number of weld metal defects. The self-protective design allows for easy use in remote locations. The BS11B wire is developed for carbon-manganese steel and ordinary rails, while the MN33 wire is suitable for the repair of austenitic manganese-type rails.
Different areas of the rail will develop different types of defects and failure modes. For example, at crossings or switches, the wheels are temporarily unsupported as they travel onto new rails. The impact generated at the crossing point is significant and frequent, leading to wear on the rail head and an increased contact angle. There are also common defects found on regular rails, such as wheel burns caused by reduced friction between the wheel and rail due to the extrusion of the wheel flange against the rail side. Additionally, when manufacturing railway switches, pre-su***cing with Corewire's specialized welding alloy for pre-protection results in switches that are more wear-resistant and have a longer service life than conventional switches.