Procedure for the thermal treatment of rails
AssigneeVoest-Alpine Schienen GmbH
InventorsAlfred Moser, Georg Prskawetz, Peter Pointner
Life of this patent
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Abstract
A method for the thermal treatment of rails, in particular of the rail head, in which cooling is carried out in a cooling agent that contains a synthetic cooling agent additive starting at temperatures above 720° C. The treatment is carried out by immersion in the cooling agent until withdrawal of the immersed areas occurs, at a surface temperature between 450 and 550° C. results without temperature equalization across the whole of the cross-section, thereby avoiding hardening of the rail web whilst maintaining an optimal cooling rate for the rail head.
Claims13
A method for the thermal treatment of a rail head of a rail wherein cooling is carried out, comprising:
- partially submerging the rail by immersing the nil head at an initial temperature of above 720° C. in a cooling agent that contains a synthetic cooling agent additive;
- and
- withdrawing the immersed rail head from the cooling agent upon obtaining a surface temperature of the rail head of between 450 and 550° C.;
- wherein the rail bead includes an inner portion and an outer portion, the outer portion being closer to a surface of the rail head than the inner portion, and wherein the rail head is withdrawn from the cooling agent while a temperature of the inner portion of the rail head is still higher than a temperature of the outer portion of the rail head.
A method for the thermal treatment of a rail head of a rail in which cooling is carried out, comprising:
- partially submerging the rail by immersing the rail head at an initial temperature of above 720° C. in a cooling agent that contains a synthetic cooling agent additive selected from at least one of glycols and polyglycols;
- and
- withdrawing the rail head from the cooling agent upon obtaining a surface temperature of said rail head of between 450 and 550° C.;
- wherein the rail head is withdrawn from the cooling agent while the temperature of the rail head at a distance of approximately 25 mm from a surface of the rail head is still higher than said surface temperature.
A method for the thermal treatment of a rail bead of a rail in which cooling is carried out, comprising:
- partially submerging the rail by immersing the rail head at an initial temperature of above 720° C. in a cooling agent with a bath temperature between 35 and 55° C. and which has a transition from film boiling to a boiling phase at a temperature at which the rail head should be withdrawn;
- and
- withdrawing the rail head when the transition occurs.
Dependencies are inferred from the claim text.