METHOD OF ALUMINOTHERMIC WELDING OF RAILS Russian patent published in 1997 - IPC

FIELD: railway transport; welding of rails. SUBSTANCE: to carry out welding of rails by this method ends of rails are arranged at one level with welding gap left between end faces. Split mould is placed in zone of welding gap around rail ends and is sealed on rails. Reaction crucible filled with metered amount of aluminothermic compound is placed above mould. Prior to pouring molten metal into split mould, ends of rails and mould are heated to 1000 C and after poring, rails and mould are held until metal is solidified and weld is formed. In process of metal pouring welding gap is filled up with metal from bottom to top, with delivery of some molten metal to middle part of welding gap after filling of lower part of split mould. At the end of pouring additional heating of rail end heads and molten metal filled in mould is carried out to temperature not lower than 800 C by delivering last portion of molten metal into space above heads of rail ends. After solidification of molten metal feed head of weld is removed from head of welded rail. EFFECT: improved quality of welded rail. 4 cl, 4 dwg