Abstract: A heat treatment apparatus that thermally treats an annular workpiece formed of a steel material by inductively heating the workpiece includes a treatment tank in which the workpiece is set and thermally treated, a holding portion that holds the workpiece at a predetermined position, an induction heating coil that surrounds the workpiece to inductively heat the workpiece, and a cooling medium that cools surfaces of the workpiece during the induction heating of the workpiece.

Abstract: Rail manufacturing method performs, on at least a head of the rail that is hot after hot-rolled at an austenite region temperature or higher or after heated to the austenite region temperature or higher, forced cooling: for 10 seconds from start of the forced cooling so that a cooling rate at a surface of the head becomes 1° C./s to 20° C./s; during a period after a lapse of 10 seconds from the start until heat generation during transformation begins at the surface so that the cooling rate becomes 1° C./s to 5° C./s; during transformation from beginning to end of the heat generation during transformation so that the cooling rate becomes lower than 1° C./s or a temperature-rising rate becomes 5° C./s or lower; and during a period after the end of the heat generation during transformation until temperature at the surface becomes 450° C. or lower so that the cooling rate becomes 1° C./s to 20° C./s.

Abstract: A system thermally treats rails. The system has a cooling device for spraying a cooling medium onto a rail to be treated. The cooling device defines a cooling path for receiving the rail to be treated. A conveyor moves the rail to be thermally treated through the cooling path. A vertically displacing device for displacing at least one of the cooling devices for adjusting a position of the one cooling device relative to the rail to be treated.

Abstract: An electric induction rail heater is provided for selectively adjusting the heated temperatures in a rail's head, web and foot sections after fabrication of the rail. Alternatively, the rail heater can be used for heating the opposing ends of two rails that are to be welded together. The electric induction rail heater is a transverse flux electric inductor that can be provided with or without magnetic cores.

Abstract: Apparatus and method are provided for making the longitudinal temperature distribution of the bulbous end of a longitudinally oriented workpiece, such as a rail's head, generally uniform when the head has a non-uniform longitudinal temperature distribution. A combination of crown and skirt electric inductors is used to achieve the generally uniform temperature distribution by modulating the magnetic field intensity produced by current flow through one or more of the combination of crown and skirt inductors as required for the non-uniformly heated regions of the rail's head.

Abstract: A method and device for heating or hardening at least an axial segment of a rotationally-symmetric surface of a work piece includes rotating the work piece about its rotational axis and moving a peripheral portion of an inductor along a longitudinal profile of the axial segment of the rotating work piece with a constant spacing between the peripheral portion and the axial segment. At least a portion of the movement of the peripheral portion is composed of a first vector component in the direction of the rotational axis and a second component extending perpendicularly to the first vector component. The peripheral portion has a length in the rotational axis direction that is less the length of the axial segment in the rotational axis direction.

Abstract: An induction heat treatment method with which temperature control is enabled, condition setting is easy, and the quality of a treatment object can be stabilized includes: a data acquiring step of heating and quench-hardening a sample of the treatment object to thereby acquire process data; a storing step of storing the process data; a checking step of checking the power supply output transition data and the quenching timing data as to validity based on the temperature transition data stored in the storing step; and a mass production step of performing heat treatment of the treatment object in accordance with the power supply output transition data and the quenching timing data stored in the storing step and checked as to validity in the checking step.

Abstract: Process for the in-line thermal treatment of rolled rails which ensures to obtain a fine pearlitic structure which is uniform through a whole predetermined superficial thickness of the rail head. There is also disclosed a new device for the thermal treatment of rails in-line with a rolling system which, as compared to the known devices, is structurally much simpler, has a high sturdiness and requires less maintenance.

Abstract: A method for restoring a worn rail section includes cleaning a worn surface of a rail section to expose a clean metal surface, heating the rail section to a first temperature before welding, welding new metal on the clean metal surface of the rail section after heating the rail section to the first temperature, heating the rail section to a second temperature after the welding to heat-treat a heat-affected area caused by the welding, and shaping the rail section, wherein the welding is performed by a gas metal arc welding (GMAW) process.

Abstract: A method of making a hypereutectoid, head-hardened steel rail is provided that includes a step of head hardening a steel rail having a composition containing 0.86-1.00 wt % carbon, 0.40-0.75 wt % manganese, 0.40-1.00 wt % silicon, 0.05-0.15 wt % vanadium, 0.015-0.030 wt % titanium, and sufficient nitrogen to react with the titanium to form titanium nitride. Head hardening is conducted at a cooling rate that, if plotted on a graph with xy-coordinates with the x-axis representing cooling time in seconds, and the y-axis representing temperature in Celsius of the surface of the head of the steel rail, is maintained in a region between an upper cooling rate boundary plot defined by an upper line connecting xy-coordinates (0 s, 775° C.), (20 s, 670° C.), and (110 s, 550° C.) and a lower cooling rate boundary plot defined by a lower line connecting xy-coordinates (0 s, 750° C.), (20 s, 610° C.), and (110 s, 500° C.).

Abstract: An induction heat treatment method with which temperature control is enabled, condition setting is easy, and the quality of a treatment object can be stabilized includes: a data acquiring step of heating and quench-hardening a sample of the treatment object to thereby acquire process data; a storing step of storing the process data; a checking step of checking the power supply output transition data and the quenching timing data as to validity based on the temperature transition data stored in the storing step; and a mass production step of performing heat treatment of the treatment object in accordance with the power supply output transition data and the quenching timing data stored in the storing step and checked as to validity in the checking step.

Abstract: In order to obtain a fine-lamellar perlite structure in the edge region of the heads of rails (1), especially hot-rolled rails for carriageways or railways, by specific thermal treatment during cooling from the rolling heat without the formation of bainite, precooling (12) occurs in order to achieve a core temperature of approximately 750-850° C., and the temperature of the more intensively cooled edge region is raised by intermediate heating (13) to at least said core temperature and finally cooled (14).

Abstract: An apparatus (10) and method for preheating welds uses a centered induction plate (12) having preferably a plurality of induction coils (30, 32) to impart the generation of heat in the materials to be welded (14), being interactively controlled by at least a temperature sensor (90, 92) and power supply control loop (16) so that even preheating can be obtained for a selected length of time given the parameters of the weld desired.

Abstract: A road wheel composition having high surface hardness and high strength, which is manufactured by a heat treatment of a metal powder containing Fe as a main component, C, Si, Mn, P, S, Al, Ti, N, Cr, and B, and a method for manufacturing a road wheel for an automobile having high surface hardness and high strength by quenching an end of a formed road wheel rim by means of high-frequency heater and cooler using the road wheel composition. Road wheel composition includes Fe as a main component, C of 0.10 to 0.40 wt %, Si of 0.15 to 0.35 wt %, Mn of 0.35 to 2.0 wt %, P of not exceeding 0.03 wt %, S of not exceeding 0.3 wt %, Al of 0.05 to 0.15 wt %, Ti of 0.005 to 0.03 wt %, Nb of 0.025 to 0.045 wt %, Cr of not exceeding 0.35 wt %, and B of not exceeding 0.005 wt %. Road wheel having excellent surface hardness and high strength is manufactured.

Abstract: An apparatus for manufacturing a case hardened journal cross includes an inductor having an open side to allow the journal cross to be inserted and withdrawn from the induction process with relative ease. The conductive frame of the inductor is shaped in a cross-like pattern that outlines the outer perimeter of a journal cross on each side of the journal cross. Because the induction coil passes across both sides of the journal cross, heat treating may be enhanced at specific locations of the outer surface of the journal cross by adjusting the distance of the induction coil from the journal cross. Also, a method for manufacturing such a journal cross includes determining the maximum stress distribution for the journal cross and, based thereon, determining the desired depth and location of the case hardening.

Abstract: The invention relates to a method for manufacturing components from critical cold forming of light metal strip, preferably naturally hard Al alloys of the AlMg or AlMg—Mn types, in which the desired component is manufactured from the strip by at least one cold forming step and the plasticity is improved before the cold forming by means of a soft annealing. According to the invention, it is proposed that the region of the longitudinal edges of the cold-slit strips is heated in a depth in the strip width of at least 1 mm to a maximum of 10 mm in such a way that a temperature of over 150° C. is reached over a time span of more than 0.1 seconds to a maximum of 10 seconds.

Abstract: A method and apparatus for repairing microcracks in the metal of a railway track. A high power laser, or equivalent energy beam generator, is moved along a track. The high power laser directs an intense beam of energy towards microcracks in the rail, a vapour space is formed in the metal of the rail, and as the laser beam moves on, the metal resolidifies and repairs the microcracks. Fusible metal may be applied to the vapour space to improve the strength and control the microstructure of the solidified metal. Pre-heating and controlled quenching may improve the crystalline microstructure of the metal after the vapour space has been formed, and, if necessary, the rail may be ground to a smooth finish. A plurality of repaired regions having deep roots are locked in the rail using unaffected metal between them.

Abstract: A method for manufacturing a rail for use in a linear motion rolling contact guide unit is provided. A rail intermediate product having a top surface, a pair of side surfaces, each formed with a guide groove portion, and a bottom surface is provided by drawing from an alloy steel material. Then the guide groove portion is hardened by induction hardening. The side surface is then ground by a profiled grinder having a grinding shape complementary to the shape of a side surface of a finished rail.

Abstract: A method for manufacturing a rail for use in a linear motion rolling contact guide unit is provided. A rail intermediate product having a top surface, a pair of side surfaces, each formed with a guide groove portion, and a bottom surface is provided by drawing from an alloy steel material. Then the guide groove portion is hardened by induction hardening. The side surface is then ground by a profiled grinder having a grinding shape complementary to the shape of a side surface of a finished rail.