METHOD FOR INDUCTIVE THERMAL HARDENING OF SWITCH RAILS AND INSTALLATION FOR ITS IMPLEMENTATION Russian patent published in 2023 - IPC C21D9/04 C21D11/00 

FIELD: railway industry.

SUBSTANCE: method for inductive thermal hardening of switch rails and installation for its implementation relate to the field of ferrous metallurgy, in particular to methods and devices for thermal hardening of railroad rails. Method for inductive thermal hardening of switch rails includes heating the head and sole and cooling them in accordance with a given program mode corresponding to the type and material of the rail, while heating is carried out by means of separate independently adjustable inductive thermal devices with heating of the head to a temperature in the range of 850-1130°C, and soles - up to a temperature in the range of 800-850°C, while the hardening of the head and sole is carried out by separate hardening devices by independent regulation of the cooling air flows of each of these hardening devices, depending on the speed of the rail and the heating temperature of the head or sole, respectively, with cooling of the rail head in two stages, while in the second stage the head is cooled to a temperature of 340-400°C, and the sole - up to 450°C. Installation for implementing the method of inductive thermal hardening of switch rails contains a control unit, which is configured to enter into it a heating and cooling program in accordance with the material and type of rail, head and sole temperature sensors, the outputs of which are connected to the control unit, heating inductive heads and soles are connected, each, with a corresponding frequency converter and a transformer-matching device with the ability to independently control the power of these inductors, and the hardening module includes separate hardening devices for the head and sole, which have the ability to independently control cooling air flows depending on the speed of the rail and on the heating temperature of the head or sole, respectively.

EFFECT: providing the necessary straightness of the rail after heat treatment, increasing the uniformity of the metal structure of the hardened layer of the head and bottom of the rail, increasing the uniform hardness of the hardened metal on the rail tread along the entire length of the profile, improving the quality of physical and mechanical properties and increasing the operational stability of the rail.

5 cl, 1 dwg