PROCEDURE FOR ALUMINO-THERMAL RAIL WELDING Russian patent published in 2011 - IPC B23K23/00 C21D7/06 C21D9/50 

FIELD: metallurgy.

SUBSTANCE: procedure consists in positioning split mould in zone of welding gap and in installation of reaction crucible above it; also, crucible is filled with a dose of aluminothermal composition. Further, ends of rails and the split mould are heated to temperature (1000-1500)°C, where upon the dose of aluminothermal composition is ignited and heated to metal melting. Melt metal from the reaction crucible is supplied to the split mould and is poured into the welding gap. Melt metal is conditioned to hardening and to formation of a welding seam. The welding seam is cooled with air-water mixture with contents of water (20-50) % and rate (7-11)°/sec to temperature [(Mn+100)°C-Mn]°C. The seam is hardened with steel shot of diameter 0.6-0.8 mm and air pressure 0.7-0.8 MPa. Welding seam is cooled in air and exterior part of welding seam is removed off a rail head.

EFFECT: raised hardness in zone of welding seam relative to base material of rail.

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