GB1042939A - Method and apparatus for heat-treating rails - Google Patents

Abstract

1,042,939. Heat-treating rails. UNITED STATES STEEL CORPORATION. Sept. 23, 1963 [Oct. 12, 1962], No. 37341/63. Heading C7N. A railroad rail 14 is heat treated by bending it in the plane of the web of the rail within the elastic limit so that the rail head is convex and the rail flange concave (see Fig. 2), continuously heating the rail head progressively from one end to the other above the austenitizing temperature e.g. to 2000‹F. using an induction heater 37, initially quenching the rail head surface progressively, e.g. using air jets from a head 45, to cause the austenite on the surface to transform to pearlite, allowing self tempering of the quenched surface e.g. to 1250‹F.by absorption of the head's internal heat, finally quenching to ambient temperature e.g. using water jets from a head 46 and releasing the rail from bending stress to permit it to straighten. For preparing a rail 14 for heat treatment, it may be positioned on spaced blocks 26 provided on an elongated carriage 10 adapted for travel longitudinally on ways 12, the blocks having a height defining the curvature of the rail flange when bent e.g. by jacks 29 engaging the rail ends and operated by pistons and cylinders 36; the bent rail may be held to the carriage by releasable jaws 27 attached thereto. The carriage with bent rail clamped thereto may then be driven by a car 19 past an induction heater 37 mounted adjacent the carriage path, means being provided for causing up and down movement and tilting of the heater during carriage travel to have the heater follow the arcuate form of the head. The quenching heads 45 and 46 are preferably similarly arranged trailing the heater. The final structure of the rail head is pearlitic but may include up to 10% procutectoid ferrite and up to 25% bainite.