Hadfield crossings casting defects
Rail crossings are located at the center of the switch; this key component blends the continuity of two railways and is subject to high stress. From a metallurgical point of view, the best suitable base metal to respond to this wear phenomenon is Hadfield 13% manganese austenitic steel.
Casting is the process used to make these complex-shaped Hadfield crossings, which must be durable and precise to withstand the stress they are put under once in use. This of course means they cannot have any defects.
During casting operations, however, it is possible for defects to occur, and if this happens, it is necessary to repair those, following a special welding procedure specification to ensure structural integrity. All repairs should therefore be qualified according to exacting standards and this is where welding consumables play a key role. It is therefore important that future repair operations should be considered during the manufacturing process.
For several years, the customer had been repairing casting defects using stick electrodes, qualified and approved by the railway network owners. However, the customer was dissatisfied with their production process and during the initial meeting explained, they required improvements and innovations in terms of their quality and process productivity.
From a productivity perspective, it became clear that the customer needed to migrate from stick welding to a more automated welding process such as FCAW. They would also require the best-suited cored wire, capable of matching or improving the results obtained with stick electrodes, whilst meeting their end users’ requirements.
Welding Alloys sets the global standard for production of flux cored and metal cored welding wires for various applications, and therefore, was well equipped to respond to the requirements.