Class / Patent application number | Description | Number of patent applications / Date published |
148581000 | Railway stock (e.g., rails, wheels, axles, etc.) | 19 |
20100300586 | PROCESS OF THERMAL TREATMENT OF RAILS AND DEVICE THEREOF - 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. | 12-02-2010 |
20110139320 | METHOD OF MAKING A HYPEREUTECTOID, HEAD-HARDENED STEEL RAIL - 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.). | 06-16-2011 |
20140060710 | HEAT TREATMENT METHOD FOR BAINITIC TURNOUT RAIL - The present disclosure discloses a heat treatment method for a bainitic turnout rail, which includes: naturally cooling the turnout rail at a temperature in an austenite region after being finishing rolled to 450-480° C. at a tread center of a rail head of the turnout rail; accelerated cooling the naturally cooled turnout rail to 230-270° C. at the tread center of the rail head, a cooling rate at the tread center and a non-working side of the rail head being 1.5-5.0° C./s, a cooling rate at the working side of the rail head increasing by 0.1-1.0° C./s based on 1.5-5.0° C./s; continuously accelerated cooling the working side, the tread center and the non-working side of the rail head at a cooling rate of 0.05-0.25° C./s to decrease a temperature of the tread center of the rail head to 265-270° C.; and finally, naturally cooling the turnout rail to an ambient temperature. | 03-06-2014 |
20140102603 | METHOD FOR HEAT-TREATING BAINITE STEEL RAIL - A method for heat-treating a bainite steel rail is disclosed. The method includes: cooling a rolled steel rail naturally to lower a surface temperature of a rail head of the steel rail to 460° C. −490° C.; cooling the steel rail forcely at a cooling rate of 2.0° C./s-4.0° C./s to lower the surface temperature of the rail head to 250° C.-290° C.; placing the steel rail in an ambient temperature until the surface temperature of the rail head is more than 300° C.; performing a tempering on the steel rail in a heating furnace at 300° C.-350° C. for 2 h-6 h; and air cooling the steel rail to the ambient temperature. Steel rails heat-treated by present method may have a stable retained austenite structure and a good mechanical performance. | 04-17-2014 |
20140182751 | HEAT TREATMENT METHOD OF TURNOUT TRACK AND THE TURNOUT TRACK - The present invention provides a heat treatment method of turnout track comprising performing an accelerated cooling on the turnout track to be treated having a railhead tread with a temperature of 650-900° C. so as to obtain the turnout track with full pearlite metallographic structure, wherein the accelerated cooling velocity performed on the working side of railhead of the turnout track is higher than that performed on the non-working side of the railhead of the turnout track. The present invention provides a turnout track obtained with a heat treatment process as depicted therein. The turnout track in present invention has good straightness; both the hardness and tensile strength of the working side of railhead are higher than that of the non-working side of railhead. | 07-03-2014 |
20140246130 | METHOD OF MAKING A HYPEREUTECTOID, HEAD HARDENED STEEL RAIL - 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.). | 09-04-2014 |
20150027599 | RAIL COOLING METHOD AND RAIL COOLING DEVICE - A rail cooling method for forcibly cooling a rail by jetting a coolant includes jetting the coolant to a foot back part of the rail from a porous plate nozzle in which a nozzle hole at an end in a width direction is smaller than a nozzle hole at a central part in the width direction and causes a cooling capacity for the end in the width direction of the underside of the base of the rail to be lower than a cooling capacity for the central part in the width direction of the underside of the base of the rail. | 01-29-2015 |
20150322553 | BAINITIC STEEL RAIL CONTAINING TRACE AMOUNTS OF CARBIDES AND PRODUCING METHOD OF THE SAME - The present invention discloses a bainitic steel rail containing trace amounts of carbides, wherein, the bainitic steel rail mainly consists of bainitic structures, the carbides have a length of 0.05-0.5 μm, the major axis of carbides is oriented to a direction at a 50-70° included angle from the direction of the major axis of bainitic ferrite plates, and the carbides account for 1%-5% by volume. The present invention further discloses a method for producing a bainitic steel rail containing trace amounts of carbides, comprising: cooling a steel rail with residual heat after finish rolling by air cooling, till the temperature at the center of the rail head tread reaches 420-450° C.; cooling the rail head part of the steel rail by accelerated cooling at a 2.0-5.0° C./s cooling rate, till the temperature at the center of the rail head tread reaches 220-240° C.; loading the steel rail into a tempering furnace and tempering at 300-350° C. for 4-6 h; then, cooling the steel rail by air cooling to the room temperature. The steel rail provided in the present invention has outstanding wear resistance and contact fatigue resistance properties, and can meet higher requirement for the service of railroad steel rails, and the product is especially applicable to heavy-duty railroads. | 11-12-2015 |
20160040263 | RAIL MANUFACTURING METHOD AND MANUFACTURING EQUIPMENT - 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. | 02-11-2016 |
20170233843 | HEAD HARDENED RAIL MANUFACTURING METHOD AND MANUFACTURING APPARATUS | 08-17-2017 |
148582000 | Treating with specified agent (e.g., heat exchange agent, protective agent, decarburizing agent, denitriding agent, etc.) or vacuum | 2 |
20100307646 | COOLING SYSTEM AND COOLING METHOD OF ROLLING STEEL - 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. The cooling system of the present invention sprays a cooling medium that is produced by mixing the cooling water that is supplied from the cooling water supply nozzle and the compressed gas for cooling that is introduced from the gas inlet and rectified by the rectifying plate toward the rolled steel bar through the nozzle holes of the nozzle plate, and performs uniform cooling of the surfaces of the rolled steel bar. | 12-09-2010 |
20160010188 | HEAT TREATMENT METHOD FOR INCREASING THE DEPTH OF HARDENING LAYER IN A STEEL RAIL AND STEEL RAIL OBTAINED WITH THE METHOD | 01-14-2016 |
148583000 | Wheel | 1 |
20190144979 | LOW COST LEAN PRODUCTION BAINITIC STEEL WHEEL FOR RAIL TRANSIT, AND MANUFACTURING METHOD THEREFOR | 05-16-2019 |
148584000 | With working | 6 |
20100116381 | INTERNAL HIGH HARDNESS TYPE PEARLITIC RAIL WITH EXCELLENT WEAR RESISTANCE AND ROLLING CONTACT FATIGUE RESISTANCE AND METHOD FOR PRODUCING SAME - An internal high hardness type pearlitic rail that has a composition containing 0.73% to 0.85% by mass C, 0.5% to 0.75% by mass Si, 0.3% to 1.0% by mass Mn, 0.035% by mass or less P, 0.0005% to 0.012% by mass S, 0.2% to 1.3% by mass Cr, and the balance being Fe and incidental impurities, in which the value of [% Mn]/[% Cr] is greater than or equal to 0.3 and less than 1.0, where [% Mn] represents the Mn content, and [% Cr] represents the Cr content, and in which the internal hardness of a rail head that is defined by the Vickers hardness of a portion located from a surface layer of the rail head to a depth of at least 25 mm is greater than or equal to 380 Hv and less than 480 Hv. | 05-13-2010 |
20100186857 | INTERNAL HIGH HARDNESS TYPE PEARLITIC RAIL WITH EXCELLENT WEAR RESISTANCE, ROLLING CONTACT FATIGUE RESISTANCE, AND DELAYED FRACTURE PROPERTY AND METHOD FOR PRODUCING SAME - An internal high hardness type pearlitic rail has a composition containing 0.73% to 0.85% by mass C, 0.5% to 0.75% by mass Si, 0.3% to 1.0% by mass Mn, 0.035% by mass or less P, 0.0005% to 0.012% by mass S, 0.2% to 1.3% by mass Cr, 0.005% to 0.12% by mass V, 0.0015% to 0.0060% by mass N, and the balance being Fe and incidental impurities, wherein the value of [% Mn]/[% Cr] is greater than or equal to 0.3 and less than 1.0, where [% Mn] represents the Mn content, and [% Cr] represents the Cr content, and the value of [% V]/[% N] is in the range of 8.0 to 30.0, where [% V] represents the V content, and [% N] represents the N content, and wherein the internal hardness of a rail head is defined by the Vickers hardness of a portion located from a surface layer of the rail head to a depth of at least 25 mm and is greater than or equal to 380 Hv and less than 480 Hv. | 07-29-2010 |
20110253268 | HIGH CARBON CONTENT AND HIGH STRENGTH HEAT-TREATED STEEL RAIL AND METHOD FOR PRODUCING THE SAME - A high carbon content and high strength heat-treated steel rail including by weight 0.80-1.20% carbon, 0.20-1.20% silicon, 0.20-1.60% manganese, 0.15-1.20% chromium, 0.01-0.20% vanadium, 0.002-0.050% titanium, less than or equal to 0.030% phosphorus, less than or equal to 0.030% sulfur, less than or equal to 0.010% aluminum, less than or equal to 0.0100% nitrogen, and iron. The steel rail has excellent wear resistance and plasticity and can satisfy the requirement for overloading. A method for producing the steal rail by heating a slab to a heating temperature, multi-pass rolling, and accelerated cooling, wherein a maximum heating temperature (° C.) of said slab is equal to 1,400 minus 100[% C], [% C] representing the carbon content (wt. %) of said slab multiplied by 100. | 10-20-2011 |
20150299832 | HIGH CARBON STEEL RAIL WITH ENHANCED DUCTILITY - This invention relates to a high carbon steel rail with enhanced ductility comprising 0.65-1.4 mass % of carbon, 0.1-1.5 mass % of silicon, 0.01-0.4 mass % of manganese, 0.1-1.5 mass % of chromium, and 0.005-0.05 mass % of titanium, with additional allowances for Mo, Nb, V, Cu, M, Co, B, N, Ca, Mg, Zr, Al, and W, with the remainder comprising iron and the inevitable impurities that displays a head surface hardness of at least 325 HB and a microstructure comprising at least 90% pearlite at a depth of between 2-20 mm below the rail head surface. The invention also relates to the process for manufacturing the high carbon steel rail with enhanced ductility. | 10-22-2015 |
20160060736 | PEARLITIC STEEL RAIL WITH HIGH STRENGTH AND TOUGHNESS AND PRODUCING METHOD THEREOF - A pearlitic steel rail with high strength and toughness and a producing method thereof. The producing method comprises: controlling the following processing conditions in a rolling procedure to produce the pearlitic steel rail with high strength and toughness: initial rolling temperature of 1,120-1,180° C., final rolling temperature of 840-880° C., rail profile reduction in last two rolling passes of 6%-12%; the steel rail is cooled to 600° C. or lower at a cooling rate ≦2.0° C./s after final rolling, and then air-cooled to room temperature; the chemical composition of the steel rail meets the following requirements: C: 0.75%-0.84%, Si: 0.30%-0.80%, Mn: 0.50%-1.50%, V: 0.04%-0.12%, Ti: 0.004%-0.02%, and 0.10%≦V+10Ti≦0.25%, [N]≦30 ppm, P≦0.020%, S≦0.008%, with the remaining content consisting of Fe and inevitable impurities. | 03-03-2016 |
20160083820 | PEARLITIC RAIL AND METHOD FOR MANUFACTURING PEARLITIC RAIL - A pearlitic rail includes a composition including in % by mass: 0.70% to 0.90% of C; 0.1% to 1.5% of Si; 0.01% to 1.5% of Mn; 0.001% to 0.035% of P; 0.0005% to 0.030% of S; 0.1% to 2.0% of Cr, remainder of the composition consisting of Fe and inevitable impurities. Surface hardness of a rail top is not less than HB 430, and hardness at a depth of 25 mm from a surface of the rail top is not less than HB 410. | 03-24-2016 |