Of Gas Composition (e.g., Carbon Content, Etc.) Patents (Class 148/216)
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Patent number: 12188112Abstract: A method for fabricating an article includes forming a billet consisting essentially of a stainless steel composition of manganese 2.00 wt. %-24.00 wt. % chromium 19.00 wt. %-30 wt. % molybdenum 0.50 wt. %-4.0 wt. % nitrogen 0.25 wt. %-1.10 wt. % carbon ?1 wt. % phosphorus ?0.03 wt. % sulfur ?1 wt. % nickel <22 wt. % cobalt <0.10 wt. % silicon ?1 wt. % niobium ?0.80 wt. % oxygen ?1 wt. % copper ?0.25 wt. % balance iron. The billet is annealed and cold worked to form an article. Without annealing of the article, the article is subsequently case hardened at a single case hardening temperature to form a surface layer on a top surface thereof. Articles formed with the indicated stainless steel composition with case hardened surface layers are also provided.Type: GrantFiled: December 16, 2022Date of Patent: January 7, 2025Assignee: Carpenter Technology CorporationInventors: Stephane Alexis Jacques Forsik, Mario Epler, Alojz Kajinic, Gaurav Lalwani, Logan Smith
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Patent number: 12183600Abstract: Provided is a method of determination of pretreatment conditions of a heat treatment furnace, wherein the pretreatment is heating a furnace interior of the heat treatment furnace while supplying a gas thereinto, the method including setting a plurality of candidates of a combination of a type of a supply gas and a heating temperature; assigning to each candidate of the combination a score determined according to a type of a target metal identified as an object to be removed in the pretreatment; and determining, from the plurality of candidates, the combination of the type of the supply gas and the heating temperature to be adopted as the pretreatment conditions, with the assigned score serving as an indicator.Type: GrantFiled: December 6, 2019Date of Patent: December 31, 2024Assignee: SUMCO CORPORATIONInventor: Yoshihiro Kuwano
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Patent number: 11624106Abstract: A carburized steel component, comprising a steel base including, by weight percent, from 0.08% to 0.35% carbon, 0.5% to 1.3% manganese, 0% to 0.35% silicon, 0.2% to 2.0% chromium, 0% to 4% nickel, 0% to 0.50% molybdenum, 0% to 0.06% niobium, and a remaining weight percent of iron, and a carburized layer of above 0.35% by weight carbon from a surface of the carburized layer to a carburized layer depth, wherein the carburized layer depth is from 0.5 mm to 3.0 mm, wherein the carburized layer comprises a microstructure including martensite, retained austenite, carbide, and less than 2% by volume non-martensitic transformation products (NMTP), and wherein the carburized layer includes a prior austenite average grain size of 3.0-8.0 microns from the surface to a depth of at least 0.2 mm.Type: GrantFiled: March 18, 2020Date of Patent: April 11, 2023Assignee: Caterpillar Inc.Inventors: Michael A. Pershing, Curtis A. Henning, Robert J. Pickerill, Scott A. Johnston
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Patent number: 10704111Abstract: A method for manufacturing of steel articles comprises nitriding (210) a steel article at a nitrification temperature in the interval 350-650° C., giving a nitrided steel article. The nitrided steel article is quenched (220) in a reactive quenching oil from the nitrification temperature. The reactive quenching oil comprises at least one of S, P, B, Mo and W. Thereby, the quenching additionally comprises coating (222) of the nitrided steel article by a solid lubricant comprising at least one of S, P, B, Mo and W. An apparatus for manufacturing of steel articles, a quenching oil and a steel article produced by the method are also disclosed.Type: GrantFiled: October 25, 2016Date of Patent: July 7, 2020Assignees: APPLIED NANO SURFACES SWEDEN AB, BODYCOTE VÄRMEBEHANDLING ABInventors: Mikael Berg, Mikael Fällström, Boris Zhmud
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Patent number: 9951816Abstract: An outer ring, an inner ring, and a ball each serving as a bearing part is made of a steel containing 0.95 mass % or more and 1.10 mass % or less of carbon, 0.05 mass % or more and less than 0.3 mass % of silicon, 0.10 mass % or more and 0.50 mass % or less of manganese, and 1.30 mass % or more and 2.00 mass % or less of chromium, with the rest made up of iron and an impurity. A surface layer region defined as a region extending to a depth of not more than 20 ?m from an outer ring raceway surface, an inner ring raceway surface, and a ball rolling surface, which are each a surface where the bearing part is in rolling contact with another part, has an average nitrogen concentration of 0.2 mass % or more and 0.7 mass % or less. Five or more carbides with a diameter of 0.5 ?m or less are present per 100 ?m2 in the surface layer region.Type: GrantFiled: October 16, 2013Date of Patent: April 24, 2018Assignee: NTN CORPORATIONInventors: Daisuke Sato, Chikara Ohki
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Patent number: 9587301Abstract: Steel for manufacturing cemented steel parts, characterized in that the composition thereof in weight percentages is: 0.1%?C?0.15%; 0.8%?Mn?2%; 1%?Cr?2.5; 0.2%?Mo?0.6%; trace elements?Si?0.35%; trace elements?Ni?0.7%; trace elements?B?0.005%; trace elements?Ti?0.1%; trace elements?N?0.01% if 0.0005%(5ppm)?B?0.005%, and trace elements?N?0.02% if trace elements?B?0.0005%(5ppm); trace elements?Al?0.1%; trace elements?V?0.3%; trace elements?P?0.025%; trace elements?Cu?1%, preferably?0.6%; trace elements?S?0.1%; the remainder being iron and impurities resulting from production. A cemented steel part made with this steel, and to the method for manufacturing same.Type: GrantFiled: August 8, 2012Date of Patent: March 7, 2017Assignee: Asco IndustriesInventor: Christophe Mendibide
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Patent number: 9487843Abstract: A method for producing a bearing ring of a rolling bearing includes the steps of: preparing a formed body constituted of hypereutectoid steel; forming an annular heated region heated to a temperature of at least an A1 point on the formed body by relatively rotating an induction heating member arranged to face part of an annular region for becoming a rolling contact surface of the bearing ring in the formed body to induction-heat the formed body along the circumferential direction of the annular region; and simultaneously cooling the whole of the heated region to a temperature of not more than an Ms point.Type: GrantFiled: January 12, 2012Date of Patent: November 8, 2016Assignee: NTN CORPORATIONInventors: Hiroshi Yuki, Chikara Ohki, Kazuhiro Yagita
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Patent number: 9365919Abstract: The present invention provides a process for reduction of time in gas-carburizing process and cooling apparatus to perform carburization by step heating of a part during carburizing heating from 800° C., 850° C., 900° C. onwards to a carburization temperature of 930° C. with the part being held at each mentioned temperature for 10 minutes by adding LPG or propane along with methanol in the furnace for activation/diffusion, the holding time is thereby reduced for carburization, thereafter the carburized parts are quenched in the invented apparatus to discharge high severity of quenching. A quenching oil flow rate of about 1.6 meters per second is critical to the process.Type: GrantFiled: September 4, 2012Date of Patent: June 14, 2016Inventor: Bhagavan Raghavan
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Patent number: 9243305Abstract: A method for producing a bearing ring of a rolling bearing includes the steps of: preparing a formed body constituted of hypereutectoid steel; forming an annular heated region heated to a temperature of at least an A1 point on the formed body by relatively rotating an induction heating member arranged to face part of an annular region for becoming a rolling contact surface of the bearing ring in the formed body to induction-heat the formed body along the circumferential direction of the annular region; and simultaneously cooling the whole of the heated region to a temperature of not more than an Ms point.Type: GrantFiled: January 12, 2012Date of Patent: January 26, 2016Assignee: NTN CORPORATIONInventors: Hiroshi Yuki, Chikara Ohki, Kazuhiro Yagita
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Patent number: 8986605Abstract: Disclosed herein is a method and gas atmosphere for a metal component in a continuous furnace. In one embodiment, the method and gas atmosphere comprises the use of an effective amount, or about 1 to about 10 percent volume of endo-gas, into an atmosphere comprising nitrogen and hydrogen. In another embodiment, there is provided a method sintering metal components in a furnace at a one or more operating temperatures comprising: providing a furnace comprising a belt comprising a wire mesh material wherein the metal components are supported thereupon; and sintering the components in the furnace in an atmosphere comprising nitrogen, hydrogen, and effective amount of endothermic gas at the one or more operating temperatures ranging from about 1800° F. to about 2200° F. wherein the amount of endothermic gas in the atmosphere is such that it is oxidizing to the wire mesh material and reducing to the metal components.Type: GrantFiled: December 13, 2010Date of Patent: March 24, 2015Assignee: Air Products and Chemicals, Inc.Inventors: Donald James Bowe, Anna K. Wehr-Aukland, John Lewis Green
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Patent number: 8465603Abstract: For regulating process gases for heat treatments of metal materials/workpieces in industrial furnaces (1), which have at least one treatment chamber (2), at least one burnoff point (4) having at least one first valve (4.1), and a regulator (5) having pressure meter (5.1), the burnoff point (4) is only to be opened as a function of requirements related to the process gas. For this purpose, in a first step, with open first valve (4.1), a quantity of a flushing gas (6.1) of the gas mixture (6) of the respective process gas is supplied in a controlled manner to the industrial furnace (1) and then burned off, in a second step, the valve (4.1) is closed, the industrial furnace (1) is regulated to a preset furnace pressure and this is permanently detected via the pressure meter (5.1), in a third step, with the target pressure of the industrial furnace achieved, this pressure is detected via the pressure meter (5.1) and maintained, the first valve (4.1) further remaining closed.Type: GrantFiled: December 15, 2010Date of Patent: June 18, 2013Assignee: IPSEN, Inc.Inventors: Werner Hendrik Grobler, Thomas Eversmann, Bernd Edenhofer, Jens Bechthold, Dirk Joritz, Nils Bernhagen
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Patent number: 8313586Abstract: A method and a device for the heat treatment of metal materials in an industrial furnace involves a heating chamber having a treatment chamber and a quenching chamber utilizing protective gas and reaction gas.Type: GrantFiled: June 18, 2009Date of Patent: November 20, 2012Assignee: Ipsen International, GmbHInventors: Bernd Edenhofer, Hendrik Grobler, Peter Haase
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Patent number: 8128761Abstract: A carbonitriding method that can improve the nitrogen permeating rate to render the carbonitriding process effective is directed to carbonitriding a workpiece formed of steel that contains at least 0.8 mass % of carbon by heating in an atmosphere including ammonia, carbon monoxide, carbon dioxide and hydrogen. The method includes an atmosphere control step, and a heating pattern control step. The atmosphere control step includes an undecomposed NH3 partial pressure control step, a CO/CO2 partial pressure control step, and an H2 partial pressure control step. The undecomposed NH3 partial pressure control step, the CO/CO2 partial pressure control step and the H2 partial pressure control step are carried out such that the partial pressure of hydrogen in the heat treatment furnace is at least 0.1 atmospheric pressure and not more than 0.3 atmospheric pressure, and ? defined by the following equation (1) is at least 2.0 and not more than 6.0, in the atmosphere control step.Type: GrantFiled: April 13, 2007Date of Patent: March 6, 2012Assignee: NTN CorporationInventor: Chikara Ohki
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Patent number: 8088328Abstract: A heat treating furnace is disclosed for nitride case hardening and gas cooling a stationary workload in the same furnace which is comprised of a single chamber and an access door. The chamber is segregated into an outer portion and an inner portion, with the inner portion being adapted to receive the workload to be nitride case hardened through the access door. The inner portion is surrounded by graphite insulation to retain the gas used to nitride case harden the workload. The inner portion further includes a plurality of graphite resistance heating elements and a plurality of graphite plates juxtaposed in near proximity to the graphite resistance heating elements forming a conduit or plenum between them. The inner portion further includes a fan assembly including a graphite radial fan wheel adapted to circulate the nitriding gas within the inner portion and through the conduit to provide uniform nitride case hardening of the workload.Type: GrantFiled: June 13, 2008Date of Patent: January 3, 2012Inventor: William R. Jones
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Publication number: 20090320962Abstract: A carburizing apparatus that performs a vacuum carburizing treatment with respect to an object includes: a carburizing furnace that contains the object; a gas supply apparatus that supplies a carburizing gas to the carburizing furnace; a light emitting device that emits light by using an in-furnace gas inside of the carburizing furnace which is supplied with the carburizing gas; a light receiving device that receives light emitted from the light emitting device; and a processing device that calculates the composition of the in-furnace gas based on the light receiving result of the light receiving device.Type: ApplicationFiled: February 14, 2008Publication date: December 31, 2009Inventors: Hiroshi Nakai, Takashi Nakabayashi
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Publication number: 20090314388Abstract: A method and a device for the heat treatment of metal materials in an industrial furnace involves a heating chamber having a treatment chamber and a quenching chamber utilizing inert gas and reaction gas.Type: ApplicationFiled: June 18, 2009Publication date: December 24, 2009Inventors: Bernd Edenhofer, Hendrik Grobler, Peter Haase
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Patent number: 7544631Abstract: The present invention provides for titanium oxide-based photocatalysts having a general formula of TiO2-X-?CXN? and self-cleaning materials that are prepared by substituting O of pure TiO2 with C and N. A preparation method comprising a process for forming thin films of TiO2-X-?CXN? by using gases such as Ar, N2, CO2, CO and O are used for reactive sputtering, and a process of heat treating at around 500° C., thereby crystallizing, is provided. The titanium oxide-based photocatalysts having a general formula of TiO2-X-?CXN? and self-cleaning materials according to the present invention have a smaller optical bandgap compared to pure titanium oxides, and therefore, the photocatalysts can be activated under the visible light range. In addition, they comprise only pure anatase crystallization phase, and since the crystallized particles are small in size, the efficiency and self-cleaning effect of the photocatalysts are very high.Type: GrantFiled: April 26, 2006Date of Patent: June 9, 2009Assignee: Korea Institute of Science and TechnologyInventors: Won-Kook Choi, Yeon-Sik Jung, Dong-Heon Kang, Kyung-Ju Lee
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Publication number: 20080149226Abstract: A method of controlling an oxygen-free heat treating process in an atmospheric pressure furnace is disclosed. The present method employs an oxygen-free gas atmosphere including hydrogen gas in concentrations between about 1.0 percent to 10.0 percent, a hydrocarbon gas, such as propylene, in concentrations of between about 0.1 percent and 10.0 percent that varies as a function of time, with the balance of the gas atmosphere being nitrogen. The presently disclosed oxygen-free carburization process uses a precisely controlled gas atmosphere to minimize inter-granular oxidation, eliminate the formation of soot and cementite, and avoid hydrogen embrittlement.Type: ApplicationFiled: December 26, 2006Publication date: June 26, 2008Inventors: Karen Anne Connery, Richard A. Novak, Simon Ho, Amitabh Gupta, Robert De Wilde
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Patent number: 7115174Abstract: In a known method for producing an oxide layer on metal parts, the metal parts are heat-treated in a treatment chamber during a carburization phase at temperatures below 1100° C. [2012° F.] in an atmosphere containing carbon monoxide and hydrogen and then, during an oxidation phase, they are oxidized at an oxidation temperature in the range from 750° C. to 950° C. [1382° F. to 1742° F.] in an atmosphere where a PH2O-to-PH2 ratio between 0.3 and 10 has been established by feeding an oxidant into the treatment chamber, a process in which an oxide layer is formed, whereby the oxygen partial pressure is determined by means of an oxygen probe and regulated at least during the oxidation phase.Type: GrantFiled: November 30, 2002Date of Patent: October 3, 2006Assignee: L'Air LiquideInventor: Hans-Peter Schmidt
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Patent number: 6969430Abstract: This invention is directed to a process and apparatus for producing high productivity carburizing. A process is introduced that uses a gas mixture made up of CO, H2, CO2, H2O, CH4 and N2, such that the product of the % CO and % H2 is greater than about 1600; the ratio of CO/CO2 is greater than 10; and the ratio of H2/H2O is greater than about 10. The gas mixture is controlled for a short time. A reactor for generating a gas mixture for carburizing steel is also introduced. This reactor is composed of a cylindrically symmetric body; a first central tube containing electrical heating elements for gas flow; a second central tube concentrically disposed around the first central tube; and a plurality of catalyst beds disposed in an annular space in a segmented fashion around the second central tube.Type: GrantFiled: June 5, 2002Date of Patent: November 29, 2005Assignee: Praxair Technology, Inc.Inventors: Jaak Stefaan Van den Sype, Alan Russell Barlow, Edison Viotto
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Patent number: 6846366Abstract: There is provided an economical carburizing method and carburization apparatus capable of carrying out carburizing treatment with a quality as high as that in a normal case and a high reproducibility even if carburizing conditions differ from those in a normal case. A carburization apparatus for carrying out carburization in an atmosphere gas containing not more than 30% by volume of carbon monoxide under a pressure of 13 to 4,000 Pa has a carburizing chamber 3 for housing an object 4 to be treated; an oxygen sensor 20 for measuring an oxygen concentration in the atmosphere gas in the carburizing chamber 3 during carburization; and a mass flow controller 5 for adjusting a composition of the atmosphere gas in the carburizing chamber 3 according to a measurement result by the oxygen sensor 20.Type: GrantFiled: January 11, 2002Date of Patent: January 25, 2005Assignee: Oriental Engineering Co., Ltd.Inventors: Kazuki Kawata, Hatsuo Sato, Shigeta Asai, Yoshiyuki Sekiya
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Patent number: 6635121Abstract: The invention relates to a method for controlling the decarburization of steel components in a furnace during heat treating processes. The concentration of CO2 and/or CO in the furnace is monitored in a first batch in order to determine periods of elevated CO2/CO concentrations, and inert gas is injected in subsequent batches during the previously determined periods of elevated CO2/CO concentrations.Type: GrantFiled: February 4, 2000Date of Patent: October 21, 2003Assignees: American Air Liquide, Inc., L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventors: Yannick Rancon, Hunter Spoon
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Publication number: 20030089426Abstract: Vacuum carburizing of ferrous workpieces is performed at low pressure in a vacuum furnace using a napthene hydrocarbon as the carburizing medium. The furnace is constructed to be generally transparent to the napthene so that cracking tends to occur at the workpiece which functions as a catalyst to minimize carbon deposits. The napthene is supplied in liquid form to fuel injectors which inject the liquid napthene as a vapor at duty cycles and firing orders to produce a uniform dispersion of the hydrocarbon gas about the work resulting in uniform carburizing of the workpieces. An in-situ methane infrared sensor controls the process. Hydrogen is added to the napthene to either assure full carbon potential and produce methane or to perform variable carburizing.Type: ApplicationFiled: July 26, 2002Publication date: May 15, 2003Inventors: Ralph Paul Poor, Garry W. Barbee, Stephen Harry Verhoff, James Edward Brug
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Patent number: 6547888Abstract: An iron-containing workpiece is case hardened by low temperature carburization during which one or more process steps—including adjusting the carburization temperature, adjusting the concentration of carburization specie in the carburization gas and reactivating the surfaces to be carburized—is carried out to enhance the overall rate and uniformity of carburization with minimized soot generation, whereby carburization can be completed faster than possible in the past.Type: GrantFiled: January 28, 2000Date of Patent: April 15, 2003Assignee: Swagelok CompanyInventors: Peter C. Williams, Steven V. Marx
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Publication number: 20020179186Abstract: The invention provides a carburization treatment method in which the carburization treatment is conducted under a condition where an atmosphere within the furnace is maintained at a high carbon potential which is slightly blow a carbon solid solubility. Preferably, the internal pressure within the furnace is kept at 0.1 to 101 kPa, the hydrocarbon gas is one, two or more than two kinds of gases selected from the group consisting of C3H8, C3H6, C4H10, C2H2, C2H4, C2H6 and CH4, while the oxidative gas is an air, an O2 gas, or CO2 gas.Type: ApplicationFiled: March 28, 2002Publication date: December 5, 2002Inventors: Hisashi Ebihara, Jun Takahashi, Fumitaka Abukawa, Keiji Yokose, Hidetoshi Juryozawa
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Publication number: 20020179187Abstract: The invention provides a carburization treatment method in which a carburization treatment is conducted simultaneously with an operation of supplying a hydrocarbon gas and an oxidative gas into a furnace kept under a reduced pressure. Preferably, the internal pressure within the furnace is kept at 0.1 to 101 kPa, the hydrocarbon gas is one, two or more than two kinds of gases selected from the group consisting of C3H8, C3H6, C4H10, C2H2, C2H4/C2H6 and CH4, while the oxidative gas is an air, an O2 gas, or CO2 gas.Type: ApplicationFiled: March 28, 2002Publication date: December 5, 2002Inventors: Hisashi Ebihara, Jun Takahashi, Fumitaka Abukawa, Keiji Yokose, Hidetoshi Juryozawa
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Patent number: 6406560Abstract: A method is provided for the thermal treatment of metal workpieces in a gas atmosphere containing nitrogen, in particular for nitrocarburizing iron articles. In order to obtain enhanced resistance to wear and corrosion in the treated workpieces, the nitrogen and carbon content present in the connecting layer of the case of the treated workpieces are intentionally adjusted by appropriately selecting the nitride coefficient KN and the carburizing coefficient KC of a reaction gas that contains ammonia, whereby hydrocarbons are added to the reaction gas for producing a relatively high carbon content in the connecting layer.Type: GrantFiled: April 28, 2000Date of Patent: June 18, 2002Assignee: Ipsen International GmbHInventors: Wolfgang Lerche, Bernd Edenhofer, Michael Lohrmann
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Patent number: 6328819Abstract: A method is provided for heat treatment of metal workpieces obtain a substantially uniform nitride layer, even in workpieces comprising high alloy iron articles. The following method steps are provided: a) heating the workpieces to a temperature between 400° C. and 500° C. in a gas atmosphere comprising only ammonia; b) continuing to heat the workpieces to a temperature between 500° C. and 700° C. in a gas atmosphere containing ammonia and an added oxidizing agent; c) maintaining the workpieces at this temperature and in this gas atmosphere for a period of between 0.1 hour and 5 hours; d) continuing to maintain the workpieces at this temperature for a period of between 1 hour and 100 hours in a gas atmosphere containing ammonia or containing ammonia and a carbon-releasing substance; and, e) cooling the workpieces to room temperature.Type: GrantFiled: April 28, 2000Date of Patent: December 11, 2001Assignee: Ipsen International GmbHInventors: Wolfgang Lerche, Bernd Edenhofer, Michael Lohrmann
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Patent number: 6258179Abstract: A carburizing method is described which is capable of dispersing cementite grains in the surface of steel uniformly and finely as not to affect fatigue strength and capable of fining the crystal grains of austenite. To prevent cementite precipitation during high temperature carburization at 980° C. or more, steel contains Al in an amount in the range of 0.05≦[Al wt %]≦2.0 and Cr in an amount in the range of 0.3≦[Cr wt %]≦4.0, and the composition of the steel satisfies the requirement represented by 1.9≧−5.6[Si wt %]−7.2[Al wt %]+1.1[Mn wt %]+2.1[Cr wt %]−0.9[Ni wt %]+1.1[Mo wt %]+0.6[W wt %]+4.3[V wt %].Type: GrantFiled: August 10, 1998Date of Patent: July 10, 2001Assignee: Komatsu Ltd.Inventors: Takemori Takayama, Naoji Hamasaka
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Patent number: 6106636Abstract: In a method of and apparatus for controlling an atmosphere in a heat treatment furnace according to the present invention, a carburizing is carried out while supplying a hydrocarbon series gas and an oxidization gas into the furnace. The quantity of a residual CH.sub.4, a partial pressure of the oxidization gas and a partial pressure of CO are measured. The quantity of each gas to be supplied into the furnace is controlled according to either one of the values of the partial pressures.Type: GrantFiled: February 17, 1998Date of Patent: August 22, 2000Assignee: Dowa Mining Co., Ltd.Inventors: Takeshi Naito, Kouichi Ogihara, Akihiro Wakatsuki, Tadanori Nakahiro, Hideki Inoue, Yoshio Nakashima
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Patent number: 6074493Abstract: This invention aims at providing a method of continuously carburizing a metal strip, which is capable of providing industrially optimum carburization conditions while attaining non-soot-generating atmospheric data, desired carburization concentration distribution and desired carburization rate, in a case where a strip passed through a carburization furnace is carburized continuously in a surface reaction rate-governing area in which the carbon concentration in a superficial layer of the strip has not yet reached an equilibruim level with respect to the time.Type: GrantFiled: September 12, 1996Date of Patent: June 13, 2000Assignee: Kawasaki Steel CorporationInventors: Tsuguhiko Nakagawa, Koushi Kuramoto, Nobuaki Hanazono, Jun Morozumi, Susumu Satoh, Susumu Okada
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Patent number: 6051078Abstract: In a method of and apparatus for controlling an atmosphere in a heat treatment furnace according to the present invention, a carburizing is carried out while supplying a hydrocarbon series gas and an oxidization gas into the furnace, and the supply of the hydrocarbon series gas is stopped either when the quantity of a residual CH.sub.4 in the furnace is changed to increasing from decreasing, or when a partial pressure of oxygen in the furnace reaches a predetermined value.Type: GrantFiled: February 16, 1998Date of Patent: April 18, 2000Assignee: Dowa Mining Co., Ltd.Inventors: Takeshi Naito, Kouichi Ogihara, Akihiro Wakatsuki, Tadanori Nakahiro, Hideki Inoue, Yoshio Nakashima
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Patent number: 5958156Abstract: Apparatus (1) and process for treating particulate material or powder (33) of a size capable of being fluidized in a retort (31) mounted for rotation on a pair of end axles (18, 41). Retort (31) is mounted on a tilt frame (5) for tilting movement in a vertical plane. Gas conduits (18A, 18B) are mounted within an axle (18) for the supply and exhaust of gas for retort (31). A conduit (55) mounted within the other axle (41) permits particulate material to be passed into or out of the retort (31) as shown in FIG. 1B. A removable injection assembly (90, FIG. 10) is utilized for the injection of additional particulate material. A removable sampling assembly (95, FIG. 11) is utilized for removing a sample of the particulate material from the retort (31). As the retort (31) is rotated, particles of the particulate material are constantly intermingled with each other and the walls of the retort (31).Type: GrantFiled: June 1, 1998Date of Patent: September 28, 1999Assignee: Kemp Development CorporationInventor: Willard E. Kemp
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Patent number: 5846341Abstract: The proposed method of carrying out diagnostics on a process for the thermo-chemical treatment of steels and alloys in a glow discharge involves monitoring the ionization characteristics of the atmosphere as revealed by the intensity of the electromagnetic radiation in various frequency intervals. The proposed device for carrying out the method in question comprises a primary converter (1) in the form of an electromagnetic radiation emitter unit and contains filtering elements (5) mounted in such a way that they can be positioned in the radiation zone in front of the receiver (6) on a rotating disk (4). The disk (4) is provided with a rotation drive (7) for positioning the elements (5).Type: GrantFiled: August 9, 1996Date of Patent: December 8, 1998Inventors: Valery Vasilyevich Shemetov, Nikolai Mikhailovich Ryzhov, Andrei Evgenievich Smirnov
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Patent number: 5795406Abstract: In a cementation method of metals in which hydrocarbon gas and oxidization gas are introduced into a heat treatment furnace, a small quantity of hydrocarbon gas of is introduced at a low pressure into the heat treatment furnace. The shift time and the gradient of the carbon potential varying toward a predetermined high or low level are controlled by increasing or decreasing the quantity of cementation gas and oxidization gas to be supplied to the furnace. After the carbon potential is reached to the high or low level, the carbon potential is maintained for a predetermined time period so as to prevent the deposited carbide from being bulked. In order to prevent the gas supply pipe from being choked with the soot of the hydrocarbon, oxidization gas of intermediate pressure is flushed into the gas supply pipe.Type: GrantFiled: December 19, 1996Date of Patent: August 18, 1998Assignee: Dowa Mining Co., Ltd.Inventors: Toshiyuki Kawamura, Hitoshi Goi, Fumitaka Abukawa
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Patent number: 5749978Abstract: A method for the forming and feeding of a gaseous atmosphere having two components, at least one of which under the form of vapour obtained from liquid, envisages to bubble a first gaseous component within a liquid component kept under controlled conditions of pressure and temperature and then to remove the gas-vapour mixture having controlled composition. In order to realise the method according to the invention, a device is foreseen that comprises a saturator reservoir containing the liquid component, means to keep the level of the liquid in the reservoir substantially constant, means to bubble a flow of gaseous component within the saturator, as well as means to control pressure and temperature inside the saturator itself. The invention can be applied in particular to the forming of carburizing atmospheres and of atmospheres used in thermal treatments of steel materials, specially gas carburizing treatments.Type: GrantFiled: March 25, 1996Date of Patent: May 12, 1998Assignee: Lentek S.r.l.Inventors: Piero Colombani, Alessandro Stucchi
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Patent number: 5741371Abstract: A method for controlling the CO contents of furnace atmosphere for carburizing and carbonitriding metallic workpieces in a furnace includes the step of directly feeding a mixture of an oxidizing reagent and a hydrocarbon-containing fuel into the furnace for producing a CO-containing furnace atmosphere. The CO contents of the furnace atmosphere is measured and compared to a preset minimal CO value. A CO-forming substance is introduced into the furnace atmosphere when the measured CO contents is no longer greater than the preset minimal CO value.Type: GrantFiled: April 22, 1996Date of Patent: April 21, 1998Assignee: Ispen Industries International GmbHInventor: Max Roggatz
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Patent number: 5599404Abstract: A substrate material to be coated with either a nitride, carbide, or oxide contains a small percent of a specific reactive element, like titanium, which forms very stable nitrides, carbides, or oxides. The material also contains larger percentages of elements, such as chromium, which form less-stable nitrides, carbides, or oxides. When the substrate material is immersed in a process medium which contains reactants, such as nitrogen, carbon, or oxygen, at a chosen elevated temperature and concentration, the less-stable nitrides, carbides, or oxides are reduced and cannot form a coating on the material surface. Thus, only a very stable nitride, carbide, or oxide can form a strong, adherent coating.Type: GrantFiled: April 25, 1995Date of Patent: February 4, 1997Inventor: Donald L. Alger
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Patent number: 5472520Abstract: A method for controlling oxygen deposition on steel sheets. The oxygen deposition value of a steel sheet measured after decarburization annealing remains at a constant value by controlling, in the decarburization annealing line for the steel sheet, the electrolytic electricity density in electrolytic degreasing equipment included in the decarburization annealing line.Type: GrantFiled: December 19, 1994Date of Patent: December 5, 1995Assignee: Kawasaki Steel CorporationInventors: Yoshinori Anabuki, Kazuo Kawamura, Yutaka Kosaka, Hirotake Ishitobi, Michio Komatsubara
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Patent number: 5456766Abstract: Process for carbonitriding a steel comprising:0.75-1.1% by weight of C;up to 1.0% by weight of Si;less than 0.015% by weight of P;up to 0.5% by weight of Mo;up to 1.2% by weight of Mn;0.5-2% by weight of Cr,the remainder being Fe,by exposing it at elevated temperatures to an atmosphere comprising at least carbon monoxide, hydrogen, nitrogen and added ammonia. This is carried out by exposing it, between 780.degree. and 900.degree. C., for from 1 to 10 hours, to an atmosphere comprising at least carbon monoxide, hydrogen and ammonia with a carbon activity between 0.90 and 1.10 and a nitrogen potential between 0.10 and 0.60% N.Type: GrantFiled: May 23, 1994Date of Patent: October 10, 1995Assignee: SKF Industrial Trading & Development Company, B.V.Inventors: Johan M. Beswick, Adian M. Kerrigan, Jan T. Slycke, Terence T. Vollmer
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Patent number: 5417774Abstract: A process for producing low-cost atmospheres suitable for annealing, brazing, and sintering ferrous and non-ferrous metals and alloys, neutral hardening low, medium, and high carbon steels, sintering ceramic powders, and sealing glass to metal from non-cryogenically produced nitrogen containing up to 5% residual oxygen is disclosed. According to the process, suitable atmospheres are produced by 1) pre-heating the non-cryogenically produced nitrogen stream containing residual oxygen to a desired temperature, 2) mixing it with more than a stoichiometric amount a hydrocarbon gas, 3) passing it through a reactor packed with a platinum group of metal catalyst to reduce the residual oxygen to very low levels and convert it to a mixture of moisture and carbon dioxide, and 4) introducing the reactor effluent stream into the heating zone of a furnace and converting in-situ a portion of both moisture and carbon dioxide with a hydrocarbon gas to a mixture of carbon monoxide and hydrogen.Type: GrantFiled: December 22, 1992Date of Patent: May 23, 1995Assignee: Air Products and Chemicals, Inc.Inventors: Diwakar Garg, Brian B. Bonner, Donald P. Eichelberger, Kerry R. Berger
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Patent number: 5366563Abstract: The surfaces of a metal or alloy component are scrubbed by a high-velocity stream of inert gas at temperatures which facilitate removal of contaminants. Simultaneous with scrubbing, the impurities are captured in a separated loop of one or more "getter" filters operating at optimized temperatures. The scrubbing and "getting" functions are followed by a rapid elevation of the temperature of the component by heating the inert gas, now essentially free of contaminants which would otherwise react with the component surface at the elevated temperatures. Thereafter, a specific protective layer-forming agent is introduced into the inert gas stream at an ideal temperature, which agent will react predictably with the component being treated to form a predetermined protective coating on its surface.Type: GrantFiled: December 28, 1992Date of Patent: November 22, 1994Assignee: General Electric CompanyInventor: Gerald W. McKenzie
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Patent number: 5348592Abstract: An improved method for producing substantially moisture- and oxygen-free, nitrogen-hydrogen atmospheres suitable for annealing, hardening, brazing, and sintering ferrous and non-ferrous metals and alloys is disclosed. According to the disclosed method, suitable nitrogen-hydrogen atmosphere is produced by 1) generating a nitrogen stream containing about 0.1 to 5% residual oxygen by a known non-cryogenic air separation technique, 2) mixing it with a pre-determined but more than stoichiometric amount of hydrogen required to convert residual oxygen to moisture, 3) converting residual oxygen to moisture by reaction with hydrogen in a catalytic reactor, 4) cooling the reactor effluent stream, and 5) removing moisture from it in a regenerative sorbent dryer.Type: GrantFiled: February 1, 1993Date of Patent: September 20, 1994Assignee: Air Products and Chemicals, Inc.Inventors: Diwakar Garg, Brian B. Bonner, Paul T. Kilhefner, Paul A. Mattiola, David L. Mitchell
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Patent number: 5298090Abstract: A process for producing low-cost atmospheres suitable for annealing, brazing, and sintering non-ferrous metals and alloys from non-cryogenically produced nitrogen containing up to 5%, residual oxygen is disclosed. According to the process, suitable atmospheres are produced by 1) pre-heating the non-cryogenically produced nitrogen stream containing residual oxygen to a desired temperature, 2) mixing it with more than a stoichiometric amount a hydrocarbon gas, 3) passing it through a reactor packed with a platinum group of metal catalyst to reduce the residual oxygen to very low levels and convert it to a mixture of moisture and carbon dioxide, and 4) using the reactor effluent stream for annealing, brazing, and sintering non-ferrous metals and alloys in a furnace.Type: GrantFiled: December 22, 1992Date of Patent: March 29, 1994Assignee: Air Products and Chemicals, Inc.Inventors: Diwakar Garg, Brian B. Bonner, Donald P. Eichelberger, Kerry R. Berger
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Patent number: 5284526Abstract: An integrated two-step process for producing low-cost atmospheres suitable for annealing ferrous and non-ferrous metals and alloys, brazing metals, sealing glass to metals, and sintering metal and ceramic powders in continuous furnaces from non-cryogenically produced nitrogen containing up to 3% residual oxygen is disclosed. The residual oxygen present in non-cryogenically produced nitrogen is converted to moisture by mixing it hydrogen and passing the mixture through a reactor packed with a platinum group catalyst in the first step of the process. The reactor effluent stream containing a mixture of nitrogen, unreacted hydrogen, and moisture is mixed with a predetermined amount of a hydrocarbon gas and introduced into the heating zone of a continuous furnace in the second step of the process to 1) convert moisture to a mixture of carbon monoxide and hydrogen by reaction with the hydrocarbon gas via water gas shift reaction and 2) produce atmospheres in-situ suitable for heat treating.Type: GrantFiled: December 22, 1992Date of Patent: February 8, 1994Assignee: Air Products and Chemicals, Inc.Inventors: Diwakar Garg, Brian B. Bonner, Donald P. Eichelberger
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Patent number: 5205873Abstract: A low pressure carburization process for metal alloy parts uses a fuel mixture consisting of hydrogen with 2 to 60% by volume ethylene. The fuel mixture is heated to a temperature between 820.degree. and 1100.degree. C. A furnace installation for carrying out the process includes a double vacuum tank or vessel arrangement with internal carburizing gas distribution, an annular space surrounding the vessel, a cover, thermocouples and a microcomputer control arrangement.Type: GrantFiled: July 1, 1991Date of Patent: April 27, 1993Assignee: Acieries Aubert & DuvalInventors: Andre Faure, Jacques Frey