Abstract: Part of an atmosphere gas in a heating zone and/or a soaking zone is sucked out and is cooled through a high-temperature gas passage of a heat exchanger by heat exchange with a gas in a low-temperature gas passage, then cooled through a gas cooler, then dehumidified to a dew point of ?45° C. or less in a dryer, then heated through the low-temperature gas passage of the heat exchanger by heat exchange with a gas in the high-temperature gas passage, and returned to the heating zone and/or the soaking zone. Part of gas flowing from the dryer toward the low-temperature gas passage of the heat exchanger is returned to a cooling zone. These can achieve a low dew point of ?45° C. or less with high energy efficiency.

Abstract: A method for manufacturing a steel plate provided with a layered structure. A method for manufacturing a steel plate includes: i) providing a high carbon steel plate; ii) homogenizing the high carbon steel plate; iii) transforming the high carbon steel plate into an austenitic phase by heating the high carbon steel plate; iv) contacting the high carbon steel plate with an oxidization gas and converting the high carbon steel plate into a steel plate comprising surface layers that are spaced apart from each other and are decarburized to be transformed into a ferritic phase, and a center layer that is located between the surface layers and is not decarburized; and v) cooling the high carbon steel plate and transforming the center layer into a martensitic phase.

Abstract: An apparatus for thermally treating and coloring a plurality of curved suture needles. The apparatus includes a conveyer for transferring the plurality of curved suture needles from a source of curved suture needles to a receiver, a housing positioned adjacent the conveyer, the housing having a first end, a second end, and an opening running from the first end to the second end, the opening aligned with the conveyer to enable the plurality of curved suture needles to pass therethrough, a heat source located within the housing for heating the plurality of curved suture needles as the plurality of curved suture needles are transferred by the conveyer from the first end of the housing to the second end of the housing and a system for providing a gas mixture containing a fractional concentration of oxygen to oxidize and colorize the surfaces of the plurality of curved suture needles as the plurality of suture needles pass through the housing.

Abstract: A method is described for batchwise heat treatment of goods to be annealed which are heated in a heating chamber after scavenging air with a scavenging gas under protective gas to a predetermined treatment temperature, with the protective gas being conveyed through the heating chamber depending on the occurrence of impurities in different quantities. In order to enable the economic use of protective gas, it is proposed that the protective gas which is withdrawn from the heating chamber after the main occurrence of impurities and which is loaded with a residual quantity of impurities is conveyed, optionally after intermediate storage, into the heating chamber during the main occurrence of impurities of a subsequent batch before non-loaded protective gas is introduced into the heating chamber.

Abstract: A cooling system that cools hot rolled long steel bar, provided with a plurality of chambers that are arranged along the longitudinal direction of the rolled steel bar. Each of the plurality of chambers is provided with a blow outlet that, facing from the chamber to the rolled steel bar, blows out compressed air for cooling that is introduced to the chamber from a gas inlet that is connected to the chamber; a nozzle plate having a plurality of nozzle holes that is provided at this blow outlet so as to face the rolled steel bar; a cooling water supply nozzle that supplies cooling water into the chamber; and a rectifying plate that is provided between the gas inlet and the cooling water supply nozzle, and that prevents the compressed gas for cooling that is introduced from the gas inlet from directly striking the nozzle plate.

Abstract: A process for the manufacture of a railroad rail of a steel alloy having a pearlitic microstructure. The rail is is shaped at a reduction rate of 1.8 to 8% and aligned straight in its longitudinal direction at a temperature between 770° C. and 1050° C., whereafter it is mounted with the head down and is allowed to cool slowly in still air to a temperature of 5 to 120° C. above the Ar3 temperature, and upon reaching this temperature at least the rail head is dipped into a cooling liquid and is cooled to the temperature of conversion of an austenitic grain microstructure into a fine pearlitic grain microstructure.

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.

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 withdrawl of the immersed areas, courses, at a surface temperature between 450 and 550° C. results without temperature equalization across the whole of the cross-section, section, there by avoiding hardening of the rail web whilst maintaining an optimal cooling rate for the rail head.

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 while maintaining an optimal cooling rate for the rail head.

Abstract: A box annealing furnace for annealing a metal sheet includes an oxygen removal unit for removing oxygen from the atmosphere in a box annealing furnace, with a gas circulation system for withdrawing atmosphere from the box annealing furnace during annealing, treating the gas, and for refeeding the deoxidized gas to the box annealing furnace. The box annealing furnace may also include a moisture removal unit for removing moisture from the gas. The oxygen removal unit and the moisture removal unit can reliably remove oxygen and moisture from the gas and suppress the formation, during annealing, of oxide film on a ferrous metal sheet.

Abstract: The present invention relates to a device for improving the adhesitivity of surface refined parts (6) to the body (7) of railway wheels (1), which surface refined parts (6) have been produced by treating the railway wheel (1) with high energy generated preferably by laser radiation (8). In order to prevent or at least obstruct the risk for loosening of the surface refined parts (6) from the body (7) of the railway wheel (1), the maximum thickness (B) of the surface refined parts (6) is selected so that the Hertzian pressure which affects the railway wheel (1) when said wheel is loaded with the maximum permitted pressure thereon is substantially carried by the body (7) of the railway wheel (1) beneath the surface refined parts (6).

Abstract: Method for raising rail joint welds lying below the traveling surface on railroad tracks by heating the weld by means of an aluminothermic mixture which solidifies after reacting, wherein a) the aluminothermic mixture (21) is used in an amount measured in kilograms equalling from one fifth to one tenth of the weight per meter of the rail (15) measured in kilograms, wherein a1) 30 to 60% of this amount is used to heat the base (10) of the rail in a length of 150 to 300 mm (as measured symmetrically with reference to the weld in the longitudinal direction) and a2) the rest of the aluminothermic mixture (21) is used in equal proportions to heat both sides of the rail web (18), b) the aluminothermic mixture (21) is ignited, c) remains on the rail (15) after igniting for a period measured in minutes which corresponds to 0.7 to 1.5 times the number of kilograms of the aluminothermic mixture (21), whereupon d) the reacted and compacted mixture is removed from the base (10) and from the web (18) of the rail.

Abstract: In the heat treatment in the field of a thermite weld between rail ends, the rail ends and the weld are enclosed within a containment filled with an aluminothermic material mixture. The mixture is ignited and the rail ends and the thermite weld are heat-treated for a given period. After the given period, the aluminothermic reaction products and the containment are removed, and an air quench unit is placed about the weld and rail ends and compressed air is directed at the weld and rail ends for a given time period. After the removal of the air quench unit, the weld is allowed to cool to ambient temperature.

Abstract: A method of air quenching a railway rail with an apparatus develops a pearlite microstructure in the head of the longitudinally travelling rail as it travels under the apparatus. A primary air chamber at a controlled pressure provides air to the top and side surfaces of the rail heads. A secondary air chamber at a separately controlled pressure provides air to the shoulders of the rail heads. More than one quench unit may be used in series, in which case the pressures in the primary air chambers may progressively increase to increase the cooling rate.