METHOD OF HEAT TREATMENT OF RAILS Russian patent published in 2006 - IPC C21D9/04 

FIELD: ferrous metallurgy; methods of heat treatment of railway rails.

SUBSTANCE: proposed method makes it possible to obtain maximum hardness (HB288) at depth of 22 mm from head rolling surface and high resistance of rails due to sufficient depth of hardened layer at homogeneous sorbitic structure. Rail is slightly cooled down after rolling heating to temperature of 820-870°C; it is cooled in two media: first with compressed air from head surface for 20-30 s at air flow rate of 3000-4000 m³/h, air temperature of 10-25°C and pressure of 0.55 Mpa; then, head is cooled with water-and-air mixture at flow rate of water of 25-30 l/min, water temperature of 10-30°C and pressure of 0.3-0.4 Mpa. Simultaneously with cooling the head, rail base is cooled with the same water-and-air mixture at temperature of 10-30°C, flow rate of 6-7 l/min and pressure of 0.08-0.09 Mpa.

EFFECT: enhanced efficiency.

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