SAIL BSP Develops Welding Technology for NCC Grade Rails
Engineers of Steel Authority of India Limited working at SAIL’s Research & Development Centre for Iron & Steel and SAIL-Bhilai Steel Plant has developed a unique welding and post-weld-controlled cooling program for Nickel-Chromium-Copper or NCC grade rails. The NCC rail which was developed in joint collaboration with Indian Railway’s research wing RDSO and IIT Kanpur under government initiative on Technology Mission on Rail Safety for laying rails in coastal regions and corrosion prone locations of Indian Railways network has shown remarkable performance under field trials over the years.
The NCC rails are prone to develop undesired microstructure and hardness in the heat-affected zone of the weld joint with conventional welding procedure. A team of RDCIS engineers have developed the strategy of welding of NCC rails through experiments at the RDCIS laboratory. The research findings were implemented at the Rail Welding Machine in Universal Rail Mill of Bhilai Steel Plant. URM modified the welding software and annealing program as per the need. After the five phases of welding experiments on NCC rails at URM, the final welding program has been developed and approval exercise as per the protocol of Indian Railway’s Flash Butt Welding Manual (Revised in 2012) was taken in July, 2021.
The approval tests were witnessed and certified by Rail India Technical and Economic Service Limited. The welding joint successfully cleared the approval test. The development has enabled BSP to supply these rails in a 260 metre welded panel with a sound and acceptable weld joint. Indian Railways were looking for these rails in 260 metre welded panels for laying tracks in coastal regions. The NCC rails guarantee double the life than normal rails under hostile corrosive environments in coastal areas.