METHOD AND APPARATUS FOR HEAT TREATING RAILS

The invention relates to the iron and steel industry, more specifically to methods and devices for heat treating of railway rails. The method for heat treating of a rail includes preheating, postheating, and cooling. The technical result is achieved by means of heating that is carried out continuously and/or intermittently according to a programmed mode. Preheating is carried out to the austenitization start temperature (point Ac 1 ) without exceeding the austenitization end temperature (point Ac 3 ). Postheating is carried out by thermal cycling in the ±-³ phase transformation region. In the intervals between individual heating devices, retention is carried out to equalize the temperature over each cross-section. The cooling speed is changed at different stages of the cooling mode. The claimed method is carried out on the proposed apparatus, which comprises a preheating zone, a thermal cycling zone, a homogenization zone with individual heating devices having intervals and/or devices therebetween for equalizing the temperature over a cross-section, a cooling zone containing cooling modules with a unit for controlling and adjusting the cooling parameters, and a self-tempering zone. The technical result of the invention consists in improved physical and mechanical properties, a rail head contact surface hardness of up to 415 HB, and increased service life of the rail. The rail is of the required straightness after heat treatment, making it possible to exclude straightening in a roller straightening machine. The range of adjustment of the heating and cooling speeds is extended, making it possible to heat treat rails made from different grades of steel.