METHOD FOR ALUMINOTHERMIC WELDING OF RAILS Russian patent published in 1998 - IPC

FIELD: rail repairing in field condition. SUBSTANCE: method comprises steps of arranging end portions of rails in the same level with welding gap between their end surfaces; placing buildup form around rail ends in zone of welding gap and sealing contact of buildup form with rail ends; placing over form reaction crucible with dose of aluminothermic composition; before pouring melt welding metal into buildup form, heating rail ends and form up to 100-1500 C; then curing melt metal until its solidification and formation of welding joint. At pouring process filling welding gap with melt welding metal from downwards to upstairs and feeding part of melt welding metal to mean portion of welding gap after filling lower portion of buildup form. At final stage of pouring additionally heating heads of rail ends and melt metal in welding gap at least until 800 C due to feeding last dozes of melt metal to space over heads of rail ends. After crystallization of welding metal removing top portion of welding joint from head of welded rail. EFFECT: enhanced quality of joints welded in field condition. 2 dwg