Ferrous (i.e., Iron Base) Patents (Class 148/319)
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Publication number: 20080202652Abstract: A ferrous seal sliding part excellent in heat crack resistance, seizure resistance and abrasion resistance is provided. The ferrous seal sliding part has a seal sliding surface, wherein the seal sliding surface has a quench hardened layer having a structure in which a martensite parent phase forms a solid solution with carbon of 0.15 to 0.6 wt % and contains cementite dispersed therein in a content of 3 to 50% by volume.Type: ApplicationFiled: January 10, 2008Publication date: August 28, 2008Inventors: Takemori Takayama, Chikara Nakao
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Patent number: 7413704Abstract: A case hardening bearing steel having an excellent rolling contact fatigue life in intermediate temperature, in addition, excellent toughness at room temperature is provided. Specific means for solving the problems are as follows. The composition contains, by mass percent, C of 0.15 to 0.30 mass percent, Si of 0.5 to 2.0 mass percent, Mn of 0.3 to 2.0 mass percent, Cr of 1.3 to 2.5 mass percent, Mo of 0.3 to 1.0 mass percent, and O of not more than 0.0012 mass percent in a range where (Si+Mo)?1.0 mass percent is satisfied, and contains iron and inevitable impurities as remnant; the maximum size of oxide nonmetallic inclusion is not more than 12.5 ?m when examined area is 320 mm2; number of the oxide nonmetallic inclusion having a diameter of equivalent circle of 3 ?m or more is not more than 250 when the examined area is 320 mm2; in addition, C density of an outer layer is adjusted to be in a range from 0.7 to 1.2 mass percent by carburization.Type: GrantFiled: April 9, 2003Date of Patent: August 19, 2008Assignees: JFE Steel Corporation, Koyo Seiko Co., Ltd.Inventors: Akihiro Matsuzaki, Takashi Iwamoto, Masao Goto, Katsuhiko Kizawa
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Publication number: 20080156399Abstract: A super carburized, low-distortion quenched member with higher performance and minimized heat-treatment distortion is provided. A process for the production thereof includes a primary treatment and a secondary treatment. The primary treatment includes heating a steel member for a machine structure to a temperature within an austenite region by vacuum carburizing (low-pressure carburizing) to have carbon dissolved at least at a eutectoid carbon concentration of a surface layer portion of the member and then quenching the member to have at least one of ultrafine carbide and nuclei of the carbide formed in the surface layer portion of the member. The secondary treatment includes subsequently heating and soaking the member to a temperature within the austenite region and then conducting rapid quenching to have ultrafine carbide precipitated in an outermost surface layer portion.Type: ApplicationFiled: February 8, 2006Publication date: July 3, 2008Inventors: Isao Machida, Hisashi Abe, Toshio Fukushima, Koji Horikiri
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Publication number: 20080145264Abstract: Low carbon carburizing (surface hardening) and higher carbon through hardening steels primarily containing molybdenum, vanadium and nickel and, to a lesser amount, chromium used for rolling contact bearings, gears and other similar applications where high hardness at elevated temperatures is required. The alloy steel includes, in % by weight: 0.05% to 1.25% C; up to 1.25% Cr; 0.40% to 4% Mn; up to 4.0% Mo; up to 2.0% V; 1.0% to 3.0% Ni; 4% to 8% (Mo+V+Ni+Cr); less than 0.20% Si; and balance Fe plus incidental additions and impurities. The method for providing a steel having improved hardness at elevated temperatures includes the steps of: (a) providing an alloy including, in % by weight: less than 1.25% Cr, 0.4% to 4% Mn, up to 4% Mo, up to 2% V, 1 to 3% Ni, 4% to 8% (Mo+V+Ni+Cr), less than 0.2% Si, a C content selected from one of 0.05% to 0.40% C defining a carburizing steel or greater than 0.40% to 1.Type: ApplicationFiled: December 19, 2006Publication date: June 19, 2008Applicant: The Timken CompanyInventors: Dennis W. Hetzner, George M. Waid
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Patent number: 7334943Abstract: A structure supporting a differential rotatably includes an inner ring arranged at the differential, an outer ring arranged at an external peripheral portion formed to surround the differential, and a tapered roller rolling between the inner ring and the outer ring. At least any one of the inner ring, the outer ring and the tapered roller has a carbo-nitrided layer and provides an austenite grain number falling within a range exceeding 10. Thus the structure can be provided with increased anti-crack strength and dimensional stability, and increased rolling contact fatigue life.Type: GrantFiled: February 27, 2004Date of Patent: February 26, 2008Assignee: NTN CorporationInventors: Kouichi Okugami, Yoshinori Muramatsu, Chikara Ohki
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Patent number: 7081174Abstract: Disclosed is a production process of a steel product for induction hardening and a steel product for carburizing, having improved grain size properties and machinability. This production process comprises the steps of: providing an ingot or bloom comprising a steel comprising, by weight, carbon (C): 0.10 to 0.45% or 0.25 to 0.70%, silicon (Si): 0.03 to 1.0%, manganese (Mn): 0.2 to 2.0%, titanium (Ti): 0.05 to 0.2%, aluminum (Al): 0.005 to 0.05%, and nitrogen (N): not more than 0.01% with the balance consisting of iron (Fe) and unavoidable impurities; and subjecting the steel ingot or bloom to a series of hot working steps including the step of rolling the steel ingot or bloom into a semi-finished steel product, the step of rolling the semi-finished steel product into a steel bar or wire rod, and the step of forging the steel bar or wire rod into a product. In the above series of hot working steps, the steel is given a thermal history in which said steel is at least once heated to 1,250° C.Type: GrantFiled: April 28, 2003Date of Patent: July 25, 2006Assignee: Sanyo Special Steel Co., Ltd.Inventors: Ryoji Hayashi, Makoto Iguchi
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Patent number: 7067019Abstract: A relatively high strength high toughness medium Carbon Copper-Nickel-Chromium alloy steel and method that eliminates and/or reduces the use of scarce, expensive alloying elements and is lower in cost than existing high strength high toughness alloy steels with comparable strength and toughness properties. In a first embodiment, the alloy steel is comprised of by weight about 0.40–1.00% Copper, about 2.50–8.00% Nickel, and about 0.80–3.50% Chromium. In a second embodiment the alloy steel is comprised of by weight about 0.55–0.70% Copper, about 1.0–6.0% Nickel, and about 1.0–2.2% Chromium.Type: GrantFiled: November 24, 2003Date of Patent: June 27, 2006Assignee: Malltech, L.L.C.Inventors: Vladimir A. Fedchun, Mark Razdolsky
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Patent number: 7037386Abstract: A rolling bearing for belt-type continuously variable transmission with a metal belt including pieces has an inner ring; an outer ring; and rolling elements, wherein at least one of the inner ring, the outer ring and the rolling element is made of an iron alloy having a chromium content of from 2.5 to 20.0% by weight.Type: GrantFiled: April 10, 2003Date of Patent: May 2, 2006Assignee: NSK Ltd.Inventors: Susumu Tanaka, Nobuaki Mitamura, Hiromichi Takemura, Yoshitaka Hayashi, Yasuo Murakami
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Patent number: 6982120Abstract: The invention relates to components made of steel, more particularly outer joint parts and inner joint parts of constant velocity joints, and to a process of heat treating such components made of steel. The heat treatment operation includes the process stages of nitriding, induction surface layer hardening and tempering, which processes follow one another. As a result of the nitriding operation, the joint parts are provided with a surface layer (15) including nitrides and a diffusion layer (18) positioned thereunderneath. The subsequent induction hardening process causes the diffusion layer (18) to be hardened, so that it comprises good supporting characteristics for supporting the surface layer (15) positioned above same.Type: GrantFiled: July 20, 2002Date of Patent: January 3, 2006Assignee: GKN Driveline Duetschland GmbHInventor: Manfred Schuster
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Patent number: 6966954Abstract: A roller bearing that provides ball and roller bearing elements comprised of M50 steel and M50NiL steel having surface hardnesses above 60 HRC, and in the range of 65-72 HRC. The hardness in the surface region is achieved by nitriding the surface to achieve a high hardness and extended life. This improvement is brought about by controlling the microstructure of the alloy by minimizing the formation of retained austenite. The material is tempered as required. The surface is then nitrided, but the nitriding operation is carefully controlled to avoid the formation of intergranular nitrides. Because of the method used to prevent the formation of intergranular nitrides, some carbon may be present to prevent the surface of the steel from becoming depleted of carbon. The hardening element in this nitro-carburizing operation is nitrogen, which forms iron nitride as Fe3N or Fe4N intragranularly.Type: GrantFiled: October 24, 2002Date of Patent: November 22, 2005Assignee: General Electric ComanyInventors: Mark Alan Rhoads, Michael Gilbert Johnson, Jonothan Allen Scheetz
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Patent number: 6878218Abstract: A high strength gear is provided which comprises a base metal of an iron-base alloy, the base metal being carburized or carbonitrided and having a tooth surface, and a coating containing Fe nitride and/or Fe carbonitride, formed on the tooth surface. A method of forming a high strength gear is also provided.Type: GrantFiled: February 20, 2002Date of Patent: April 12, 2005Assignees: Nissan Motor Co., Ltd., Kabushiki Kaisha Kobe Seiko ShoInventors: Takuro Yamaguchi, Keizo Otani, Jun Katoh, Toshiki Satou, Satoshi Abe, Masakazu Ikeda
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Patent number: 6869489Abstract: A steel for a high bearing pressure-resistant member, having a high machinability. The steel is formed of a machine structural steel comprising carbon in an amount ranging from 0.15 to 0.25% by weight, silicon in an amount of not less than 0.4% by weight, nickel in an amount ranging from 1 to 3% by weight, chromium in an amount ranging from 1.2 to 3.2% by weight, and molybdenum in an amount ranging from 0.25 to 2.0% by weight. The machine structural steel contains carbide precipitated under a heat treatment for spheroidizing. The carbide has an average particle size of not larger than 1 ?m and the maximum particle size of not larger than 3 ?m.Type: GrantFiled: May 15, 2001Date of Patent: March 22, 2005Assignee: Nissan Motor Co., Ltd.Inventors: Toshimitu Kimura, Tatsuomi Nakayama, Hiroo Ueda, Noriko Uchiyama
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Patent number: 6858100Abstract: A rolling bearing including a rolling element made of steel is provided. The rolling element has a hardness of 620 to 750 HV in its interior. The rolling element is so constructed that the hardest point may exist within a depth of 10% of its diameter from a rolling contact surface of the rolling element, and that the hardness at this point is made higher by 20 to 150 HV than the hardness in the interior.Type: GrantFiled: July 23, 2002Date of Patent: February 22, 2005Assignee: Koyo Seiko Co., Ltd.Inventors: Hisashi Harada, Masao Goto, Hajime Tazumi
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Patent number: 6841122Abstract: A hot working die steel contains 0.05-0.25% C, 0.30% or less Si, 0.03% or less Mn, 1.0% or less Ni, 5.0-13.0 % Cr, 2.0% or less Mo, 1.0-8.0% W, 1.0-10.0% Co, 0.003-0.020% B, 0.005-0.050% N, and the balance consisting essentially of Fe and unavoidable impurities. If desired, the hot working die steel may further contain 0.01-1.0% V and 0.01-1.0% of at least one kind selected from Nb and Ta.Type: GrantFiled: April 29, 2002Date of Patent: January 11, 2005Assignee: The Japan Steel Works, Ltd.Inventors: Rinzo Kayano, Eiji Maeda
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Publication number: 20040265620Abstract: A chain including chain pins 15, which connect an inner link plate and an outer link plate, are made of carburized or refined steel, and have the entire surface on which a large number of dimples 17 are provided which are formed through a primary shot peening performed at an arc height value of 0.35 to 0.8 mmA Furthermore, dimples 21 with a size smaller than that of the dimples 17 are formed by applying a secondary shot peening performed at an arc height value smaller than that of a primary shot peening to the dimples 17 which have been subjected to the primary shot peening.Type: ApplicationFiled: May 4, 2004Publication date: December 30, 2004Inventor: Shinichiro Sugiyama
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Publication number: 20040256029Abstract: There is provided an inexpensive rolling element used under high interface pressure such as induction hardened gears, the rolling element being improved in the seizure resistance of its tooth flanks and having a temper hardness of HRC 50 or more at 300° C. To this end, the rolling element is made from a steel material containing at least 0.45 to 1.5 wt % C and one or more alloy elements selected from 0.1 to 0.5 wt % V and 0.3 to 1.5 wt % Cr, and has a rolling contact surface layer having a structure tempered at low temperature in which 2 to 18% by volume cementite disperses in a martensite parent phase formed by induction heating and cooling and containing 0.25 to 0.8 wt % carbon solid-dissolving therein.Type: ApplicationFiled: March 1, 2004Publication date: December 23, 2004Applicant: KOMATSU LTD.Inventors: Takemori Takayama, Masanari Furumoto, Chikara Nakao, Noriko Morioka
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Patent number: 6770152Abstract: The present invention provides a rolling bearing having high wear resistance at high temperature and with reduced manufacturing cost. At least one of an inner ring, an outer ring and rolling elements is formed of the following steel material into a predetermined shape, then applied with hardening and tempering at a temperature of 240° C. or higher or 350° C. or lower to make the Vickers hardness (Hv) on the raceway surface and/or rolling surface to 720 or more. The steel material contains, as the alloy ingredient, 0.8% by weight or more and 1.2% by weight or less of C, 0.5% by weight or more and 2.5% by weight or less of Si, 0.7% by weight or more and 1.5% by weight or less of Cr, 0.8% by weight or more and 2.0% by weight or less of Mo and 0.3% by weight or more and 1.2% by weight or less of Mn, with a ratio of Mo to Cr (Mo/Cr: weight ratio) of 1.1 or more.Type: GrantFiled: April 24, 2001Date of Patent: August 3, 2004Assignee: NSK Ltd.Inventors: Shigeru Okita, Akihiro Kiuchi, Hiromichi Takemura, Tomonobu Yoshikawa
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Publication number: 20040094238Abstract: Bearing steel containing 0.10 wt % to 0.35 wt % of C, less than 0.5 wt % of Si, 0.3 wt % to 1.5 wt % of Mn, 0.03 wt % or less of P, 0.03 wt % or less of S, 1.0 wt % to 3.5 wt % of Ni, 1.0 wt % to 5.0 wt % of Cr, 0.03 wt % to 2.5 wt % of Mo, 0.005 wt % to 0.050 wt % of Al, 0.003 wt % or less of Ti, 0.0015 wt % or less of O, 0.025 wt % or less of N, and a substantially residual part of Fe, wherein the bearing steel after carburizing or carbonitriding treatment exhibits a surface C concentration of not lower than 0.9%, contains 15% by area or less of carbide and contains 0.1% by area or less of rod-like carbide 10 having an aspect ratio of not lower than 3 in terms of the ratio of major diameter to minor diameter and having a minor diameter of not smaller than 2 &mgr;m.Type: ApplicationFiled: November 12, 2003Publication date: May 20, 2004Applicant: Koyo Seiko Co., Ltd.Inventors: Toshiya Kinami, Toshimitsu Kimura, Hisato Nishisaka, Masao Goto
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Publication number: 20040050456Abstract: A fuel injection valve for internal combustion engines, having a valve body (1) and at least one injection opening (11) embodied in it, through which opening, controlled by a valve needle (5) that cooperates with a valve seat (9) embodied in the valve body (1), fuel can be injected into the combustion chamber of the engine. The valve body (1) comprises a high-alloy hot-work steel, which has been hardened by a case-hardening process (FIG. 1).Type: ApplicationFiled: September 15, 2003Publication date: March 18, 2004Inventors: Dieter Liedtke, Alfred Hoch, Franz Wolf
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Patent number: 6702981Abstract: High speed steel (HSS) compositions having less C and Cr contents than standard grades of HSS to permit carburization using conventional techniques. The alloys contain less than 0.40 wt. % C and less than 2% Cr. The low Cr content is a critical factor in enhancing the ease of carburizing the present steels. The resulting HSS compositions possess high hardness and fracture resistance. More particularly, the steels include, in % by weight: 0-0.4% C; 0.5-1.5% Cr; 1.5-3.5% Ni; 0.1-0.6% M; 0.15-0.65% Si; 0.03 max % P; 0.03 max % S; one or more members selected from the group consisting of 4.0-15.3% Mo; 1.0-5.7% V; up to 13% Co and up to 28% W, and wherein the aggregate amount of %Cr+%Mo+%V+%W+%Co is between 7.5-35% and balance essentially Fe and incidental impurities. A method for treating the above alloy includes the steps of carburizing at about 960° C. followed by quenching, preheating to about 870° C. followed by austenitizing at 1125° C.-1225° C.Type: GrantFiled: December 5, 2001Date of Patent: March 9, 2004Assignee: The Timken CompanyInventor: Dennis W. Hetzner
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Patent number: 6699333Abstract: The invention discloses a carburizing steel composition comprising, by weight: 0.06% to 0.18% of C; 0.5% to 1.5% of Si; 0.2% to 1.5% of Cr; 1% to 3.5% of Ni; 1.1% to 3.5% of Mo; and, if appropriate: at most 1.6% of Mn; and/or at most 0.4% of V; and/or at most 2% of Cu; and/or at most 4% of Co; the complement being constituted by iron and residual impurities; the amounts of Ni, Mn, Cu, Co, Cr, Mo and V in said composition, expressed by weight, satisfying the following relationships: 2.5≦Ni+Mn+1.5Cu+0.5Co≦5 (1) 2.4≦Cr+Mo+V≦3.7 (2) and a process for producing carburized and treated parts produced from the compositions.Type: GrantFiled: February 26, 2001Date of Patent: March 2, 2004Assignee: Aubert & DuvalInventor: Philippe Dubois
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Publication number: 20040035499Abstract: The pitting resistance of a gear is increased by hardening its tooth flanks through application of carburizing/quenching, bright hardening and induction hardening to a steel material capable of providing significantly improved softening resistance in tempering at a low temperature of 300 to 350° C.Type: ApplicationFiled: August 13, 2003Publication date: February 26, 2004Applicant: KOMATSU LTDInventors: Takemori Takayama, Naoji Hamasaka, Noriko Morioka
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Patent number: 6685596Abstract: A blank for disc is heat treated for adjusting a surface hardness thereof to not less than Hv700. The blank has a spline hole thereof heated by high frequency heating while cooling a race thereof. Subsequently, the spline hole is subjected to slow cooling. Thus is obtained a disc having a surface hardness of not less than Hv700 at the race, and a surface hardness of not more than Hv600 at the spline hole, the disc wherein at least a thin portion is varied in hardness between a hardened layer of a bottom of the spline hole and a hardened layer of the race by an amount of not less than Hv20 per 1-mm depth.Type: GrantFiled: February 27, 2002Date of Patent: February 3, 2004Assignee: Koyo Seiko Company, Ltd.Inventors: Masao Goto, Kiichiro Yamashita, Shinji Yasuhara
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Patent number: 6680129Abstract: Chain parts and other steel articles are provided with hard, wear-resistant carbide coatings by tumbling them in a heated retort with a particulate mix which includes a source of vanadium and/or niobium. The steel substrate comprises a steel having at least 0.2% carbon, preferably 0.7-1.2%. Where the chromium content of the steel is 4-12%, preferably 4-8%, the chemical deposition process includes drawing a small amount of chromium from the steel substrate into the vanadium or niobium carbide coating, where it is distributed substantially homogeneously, helping to provide adhesion strength to the coating.Type: GrantFiled: October 28, 2002Date of Patent: January 20, 2004Assignee: BorgWarner Inc.Inventors: Yumin Wang, Yoshito Hanayama, Doug Fornell, Naosumi Tada, Kunihiko Mishima
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Patent number: 6666792Abstract: A toroidal continuously variable transmission is characterized by comprising an input disk, an output disk, trunnions, power rollers, and thrust rolling-element bearing, in which at least one of the input disk, output disk and power rollers of a power roller bearing is formed of an alloy steel and subjected to either carburizing processing and polishing or carbonitriding processing and polishing, and at least one of the input disk, output disk and the inner ring of the power roller bearing has an efficient hardened layer of Hv 653, which has a depth of 2.0 mm or more and 4.00 mm or less from the surface.Type: GrantFiled: August 16, 2002Date of Patent: December 23, 2003Assignee: NSK Ltd.Inventor: Tomonobu Yoshikawa
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Patent number: 6656293Abstract: A method for treating a surface of a first component wherein at least a portion of the surface of the first component contacts a surface of a second component. The method includes forming a compound layer at at least a portion of the surface of the first component by a thermochemical diffusion treatment and isotropically finishing the at least a portion of the surface of the first component that contacts the surface of the second component.Type: GrantFiled: December 10, 2001Date of Patent: December 2, 2003Assignee: Caterpillar IncInventors: Jared A Black, Matthew Thomas Kiser, Gary Leroy Biltgen
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Publication number: 20030200837Abstract: A porous metal body having a foam structure of 500 &mgr;m or less in average pore diameter, wherein the skeleton is composed of an alloy primarily including Fe and Cr, and Cr carbide or FeCr carbide is uniformly dispersed in the texture. The metal porous body is produced by preparing a slurry primarily containing an Fe oxide powder having an average particle diameter of 5 &mgr;m or less, at least one powder selected from metallic Cr, Cr alloys, and Cr oxides, a thermosetting resin, and a diluent, applying a coating of this slurry to a resin core body having a foam structure, performing drying, and thereafter, performing firing in a non-oxidizing atmosphere so as to produce a metal porous body having the aforementioned skeleton structure.Type: ApplicationFiled: January 28, 2003Publication date: October 30, 2003Inventors: Takahiro Matsuura, Keizo Harada
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Patent number: 6635126Abstract: Steel alloys susceptible to case and core hardening comprising 0.05 to 0.24 weight percent carbon; 15 to 28 weight percent cobalt and 1.5 to 9.5 weight percent in nickel, small percentages of one or more additives: chromium, molybdenum, and vanadium; and the balance iron.Type: GrantFiled: November 25, 2002Date of Patent: October 21, 2003Assignee: Northwestern UniversityInventors: Charles J. Kuehmann, Gregory B. Olson, John P. Wise, Carelyn Campbell
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Publication number: 20030155045Abstract: The surfaces of a stainless steel part are made harder without sacrificing corrosion resistance by subjecting the part to low temperature carburization. The soot layer formed as a by-product of carburization is then removed without removing the non-coherent metal oxide layer which also forms as a by-product. A solid lubricant is then applied to reduce the coefficient of friction of the carburized surface. The by-product metal oxide layer acts as an anchor keeping the solid lubricant in place.Type: ApplicationFiled: February 5, 2003Publication date: August 21, 2003Inventor: Peter C. Williams
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Patent number: 6607850Abstract: Chain parts and other steel articles are provided with hard, wear-resistant carbide coatings by tumbling them in a heated retort with a particulate mix which includes a source of vanadium and/or niobium. The steel substrate comprises a steel having at least 0.2% carbon, preferably 0.7-1.2%. Where the chromium content of the steel is 4-12%, preferably 4-8%, the chemical deposition process includes drawing a small amount of chromium from the steel substrate into the vanadium or niobium carbide coating, where it is distributed substantially homogeneously, helping to provide adhesion strength to the coating.Type: GrantFiled: October 28, 2002Date of Patent: August 19, 2003Assignee: BorgWarner, Inc.Inventors: Yumin Wang, Yoshito Hanayama, Doug Fornell, Naosumi Tada, Kunihiko Mishima
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Publication number: 20030102054Abstract: A rolling, sliding part comprises a bearing steel, is subjected to a carburizing treatment and has a surface layer from a surface the part to a depth to which a maximum shear stress acts. The surface layer is 1.0 to 1.6 wt. % in total carbon content, has a matrix containing 0.6 to 1.0 wt. % of solid-solution carbon, and contains a precipitating carbide in an amount of 5 to 20% in area ratio, the carbide being up to 3 &mgr;m in particle size. The rolling or sliding part is improved in wear resistance, usable with a lubricant free of or less susceptible to impression by extraneous matter present in the lubricant, and less susceptible to compressive stress due to the extraneous matter, with the development of cracks suppressed.Type: ApplicationFiled: November 14, 2002Publication date: June 5, 2003Applicant: KOYO SEIKO CO., LTD.Inventor: Katsuhiko Kizawa
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Publication number: 20030094216Abstract: Steel alloys susceptible to case and core hardening comprising 0.05 to 0.24 weight percent carbon; 15 to 28 weight percent cobalt and 1.5 to 9.5 weight percent in nickel, small percentages of one or more additives: chromium, molybdenum, and vanadium; and the balance iron.Type: ApplicationFiled: November 25, 2002Publication date: May 22, 2003Applicant: Northwestern UniversityInventors: Charles J. Kuehmann, Gregory B. Olson, John P. Wise, Carelyn Campbell
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Publication number: 20030094215Abstract: A rolling support device excellent in both of the characteristics of durability and corrosion resistance is provided. The inner ring (1) and the outer ring (2) comprises an austenitic stainless steel and has, on a raceway surface, a carburizing hardened layer containing no substantial carbides at a Vickers hardness (Hv) of 650 or more. The carburizing hardened layer is formed by applying fluoriding and then applying carburizing at a temperature of 540° C. or lower. The rolling element (3) is made of Si3N4.Type: ApplicationFiled: October 17, 2001Publication date: May 22, 2003Inventors: Susumu Tanaka, Hiroyuki Ito
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Publication number: 20030075244Abstract: A bearing pressure-resistant member, including a matrix and a carbide dispersed in the matrix, the carbide having an average particle size of not more than 0.3 &mgr;m. A carbon (C) content in an outer surface of the bearing pressure-resistant member is in a range of 0.6 to 1.5 mass percent. A process for making the bearing pressure-resistant member including subjecting a workpiece containing C to either of gas carburizing and gas carbonitriding to enhance the C content in the outer surface of the workpiece to 0.6 to 1.5 mass percent, holding the workpiece at a first temperature not more than an Ac1 transformation point under reduced pressure, heating the workpiece to a second temperature not less than the Ac1 transformation point under reduced pressure, followed by holding the workpiece at the second temperature, and subjecting the workpiece to quenching.Type: ApplicationFiled: May 3, 2002Publication date: April 24, 2003Applicant: NISSAN MOTOR CO., LTD.Inventors: Yutaka Kurebayashi, Toshimitsu Kimura, Takuro Yamaguchi, Keizo Otani, Noriko Uchiyama
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Publication number: 20030056859Abstract: A case hardening steel high in impact strength, consists essentially of carbon in an amount of from 0.1 to 0.3% by weight, silicon in an amount of from more than 0.3 to 1.0% by weight, manganese in an amount of from 0.3 to 1.7% by weight, phosphorus in an amount of not more than 0.03% by weight, sulfur in an amount of not more than 0.03% by weight, molybdenum in an amount of not more than 1.0% by weight, aluminum in an amount of not more than 0.04% by weight, nitrogen in an amount of not more than 0.03% by weight, and balance being iron and inevitable impurities. The case hardening steel meets an equation of [C %]+5([P %]+[S %])≦([Mn %]+[Mo %]+1.8)/8.Type: ApplicationFiled: July 17, 2002Publication date: March 27, 2003Applicant: NISSAN MOTOR CO., LTD.Inventors: Tomoki Hanyuda, Tuyoshi Nakamura, Takao Hayashi, Hideki Usuki, Masatoshi Honda, Yutaka Kurebayashi, Naomi Miura, Youichi Murakami
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Patent number: 6537390Abstract: An antifriction bearing comprises bearing rings and rolling members which are made from a steel material containing 0.15 to 0.3 wt. % of carbon by being subjected to heat treatments including carburizing. The surface layer of raceway surface of each of the bearing rings and the surface layer of rolling surface of each of the rolling members are 1.0 to 1.5 wt. % in carbon content, 64 to 66 in Rockwell hardness C, 150 to 2000 MPa in compressive residual stress, up to 3 &mgr;m in maximum carbide particle size and 10 to 25% in carbide area ratio, at a depth of 0 to 50 &mgr;m as measured from the outermost surface of the surface layer. The surface layers are 0.75 to 1.3 wt. % in carbon content, 150 to 1000 MPa in compressive residual stress, 25 to 45% in residual austenite content, up to 1 &mgr;m in maximum carbide particle size and up to 15% in carbide area ratio, at a depth of 50 to 200 &mgr;m as similarly measured from the outermost surface.Type: GrantFiled: November 8, 2000Date of Patent: March 25, 2003Assignee: Koyo Seiko Co., Ltd.Inventor: Masao Goto
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Patent number: 6527877Abstract: An alloy having two constituents: a crystal structure of orderly solid iron-based solution; a non-metallic phase at least partially soluble in iron including particles which are uniformly dispersed in the volume of the first phase and are of suitable size. In a preferred embodiment, the alloy contains iron with dissolved and bonded carbon as the first phase, which forms the crystal structure, and material partially soluble in iron, for example structurally free molecular carbon, is taken as the second non-metallic phase. The alloy preferably contains the components at the following ratios, % by mass: carbon in a dissolved and in a bonded state: 0.01-1.00; free carbon: 0.01-2.24; iron: balance. The ratio of free carbon to that of carbon in a dissolved and in a bonded state ranges from 0.01 to 20. The alloy Is preferably produced by melting out low carbon semi-product, overheating the semi-product above a liquidus temperature, for example by 20-70° C.Type: GrantFiled: April 22, 1999Date of Patent: March 4, 2003Assignee: Limited Liability Company “SKM”Inventor: Genrikh Alexeevich Dorofeev
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Publication number: 20030029525Abstract: A rolling bearing including a rolling element made of steel is provided. The rolling element has a hardness of 620 to 750 HV in its interior. The rolling element is so constructed that the hardest point may exist within a depth of 10% of its diameter from a rolling contact surface of the rolling element, and that the hardness at this point is made higher by 20 to 150 HV than the hardness in the interior.Type: ApplicationFiled: July 23, 2002Publication date: February 13, 2003Applicant: KOYO SEIKO CO., LTD.Inventors: Hisashi Harada, Masao Goto, Hajime Tazumi
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Patent number: 6491767Abstract: Steel alloys susceptible to case and core hardening comprise 0.05 to 0.24 weight percent carbon; 15 to 28 weight percent cobalt and 1.5 to 9.5 weight percent in nickel, small percentages of one or more additives: chromium, molybdenum, and vanadium; and the balance iron. Carburized roll form and punch dies made from case hardened steel alloys with a reduced hardness core provide high wear and fatigue resistance as well as improved contact and bending fatigue resistance thereby avoiding premature failure and extending the useful life of such dies.Type: GrantFiled: September 19, 2000Date of Patent: December 10, 2002Assignee: Northwestern UniversityInventor: Charles J. Kuehmann
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Publication number: 20020179188Abstract: A high strength gear is provided which comprises a base metal of an iron-base alloy, the base metal being carburized or carbonitrided and having a tooth surface, and a coating containing Fe nitride and/or Fe carbonitride, formed on the tooth surface. A method of forming a high strength gear is also provided.Type: ApplicationFiled: February 20, 2002Publication date: December 5, 2002Applicant: NISSAN MOTOR CO., LTD. and KABUSHIKI KAISHA KOBE SEIKO SHOInventors: Takuro Yamaguchi, Keizo Otani, Jun Katoh, Toshiki Satou, Satoshi Abe, Masakazu Ikeda
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Patent number: 6488789Abstract: A wheel bearing unit is provided in which the service life level is improved without making the size and weight of the bearing unduly large. The wheel bearing unit for rotatably supporting a car wheel on the body of a motor vehicle comprises a rotary member, an outer ring, and double rows of rolling elements. The rotary member comprises a hub wheel to which a car wheel is attached and an inner ring press-fitted to the outer circumference of the smaller end face of the hub wheel, wherein double rows of raceway surfaces are formed in the outer circumferential surfaces of the hub wheel and the inner ring, respectively. The outer ring has double rows of raceway surfaces formed therein so as to be opposite to the raceway surfaces of the hub wheel and the inner ring, and is fixedly coupled to a car-body-side knuckle. The double rows of rolling elements are interposed between the raceway surfaces of the hub wheel, the inner ring, and the outer ring.Type: GrantFiled: January 17, 2001Date of Patent: December 3, 2002Assignee: NTN CorporationInventors: Eiji Tajima, Motoharu Niki
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Patent number: 6485582Abstract: Steel alloys susceptible to case and core hardening comprising 0.05 to 0.24 weight percent carbon; 15 to 28 weight percent cobalt and 1.5 to 9.5 weight percent in nickel, small percentages of one or more additives: chromium, molybdenum, and vanadium; and the balance iron.Type: GrantFiled: August 17, 2000Date of Patent: November 26, 2002Inventors: Charles J. Kuehmann, Gregory B. Olson, John P. Wise, Carelyn Campbell
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Patent number: 6464801Abstract: Steel alloys susceptible to case and core hardening comprising 0.05 to 0.24 weight percent carbon; 15 to 28 weight percent cobalt and 1.5 to 9.5 weight percent in nickel, small percentages of one or more additives: chromium, molybdenum, and vanadium; and the balance iron.Type: GrantFiled: August 14, 2001Date of Patent: October 15, 2002Assignee: Northwestern UniversityInventors: Charles J. Kuehmann, Gregory B. Olson, John P. Wise, Carelyn Campbell
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Patent number: 6458220Abstract: Steel alloys susceptible to case and core hardening comprise 0.05 to 0.24 weight percent carbon; 15 to 28 weight percent cobalt and 1.5 to 9.5 weight percent in nickel, small percentages of one or more additives: chromium, molybdenum, and vanadium; and the balance iron. Blades for ice skating or other sports equipment made from such alloys provide predictable and reproducible characteristics and permit fabrication with hardened edges on a ductile, strong substrate or base.Type: GrantFiled: September 19, 2000Date of Patent: October 1, 2002Assignee: Northwestern UniversityInventors: Charles J. Kuehmann, Priscilla A. Bernikowicz, Gregory B. Olson, John P. Wise, Carelyn E. Campbell
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Patent number: 6454880Abstract: Multi-layer material for die cast tooling component includes a low to medium carbon steel with alloying amounts of vanadium, manganese and molybdenum, quenched to at least 10 Bar and nitrocarburized to achieve a multiple layer structure with at least an outside lubricious layer, retaining hardness in the core. The method for producing the multi-layer material includes alloying the core material, forming into desired net shape, quenching and nitrocarburizing. A high endurance die cast tooling component for use in tooling applications includes a core material of at least 80 percent by volume martensite with no more than 15 percent by volume of retained austenite with at least two surface layers for lubricity and endurance. The tooling components may include shot sleeves, plungers, plunger tips, bushings, and core pins.Type: GrantFiled: September 29, 2000Date of Patent: September 24, 2002Inventor: Herbert (Lonny) A. Rickman, Jr.
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Patent number: 6440232Abstract: In a toroidal-type continuously variable transmission, at least one of components including inner and outer races of a power roller bearing, an input disk, and an output disk is composed of an alloy steel material containing C: 0.15 to 0.5 wt %, Si: 0.1 to 1.5 wt %, Mn: 0.1 to 1.5 wt %, Cr: 0.5 to 3.0 wt %, and at least one kind selected from Mo: 0.1 to 3.0 wt % and V: 0.1 to 3.0 wt %, a content of 0 in the alloy steel material being set to be not more than 9 ppm; and the surface of the at least one component after carbonitriding, hardening and tempering treatments is set to contain C: 0.8 to 1.2 wt % and N: 0.05 to 0.20 wt %, and the at least one component has surface hardness of Hv 720 or more, and Mo.V carbide/carbonitride, the average particle size of which is in a range of from 50 nm to 500 nm is dispersed and precipitated on a race surface or in a range of from the race surface to a deep position where a maximum shearing stress is generated.Type: GrantFiled: July 21, 2000Date of Patent: August 27, 2002Assignee: NSK Ltd.Inventors: Hiromichi Takemura, Yasuo Murakami, Nobuo Goto, Takashi Imanishi
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Patent number: 6440233Abstract: An inner ring and an outer ring are composed as follows. These members are fabricated with a steel for bearing containing carbon 0.6 wt % or higher. A carbonitrided layer is formed in a raceway surface. The amount of residual austenite at a position of 2% Da depth in the raceway surface is determined to be 1.0 vol % or lower. Hardness at the position of 2% Da depth is set to be HRC58 or more. Nitrogen content (Np) at the position of 2% Da depth is 0.05 wt % or more. A multiple Gd of an impression resistance expressed with the following formula (1) is 1.6 or more, Gd=(H0.2/500)+2·Np (1), wherein in the formula, H0.2 is meant by Vickers hardness at the position of 2% Da depth.Type: GrantFiled: March 27, 2001Date of Patent: August 27, 2002Inventors: Shigeru Okita, Susumu Tanaka, Tomonobu Yoshikawa
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Patent number: 6423158Abstract: A roller bearing which can sufficiently ensure an endurance life of rollers even under conditions where debris contamination and temperature rise are large. As the material for an outer ring, inner ring and tapered rollers, a steel in which the Si and-Mn contents are increased is used, and after it has been treated to carbo-nitriding, it is quenched to adjust the amount of retained austenite in the carbo-nitrided layer formed on the surface layer of each part to 20-50 vol %. Thus, it is possible to prevent surface peeling resulting from initiation and propagation of cracks,. thereby greatly improving the endurance life of the rolling bearing under conditions in which debris contamination or temperature rise at bearing portions is large.Type: GrantFiled: December 15, 1999Date of Patent: July 23, 2002Assignee: NTN CorporationInventors: Kikuo Maeda, Hirokazu Nakashima, Akio Okayama
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Patent number: 6413328Abstract: High surface pressure resistant steel parts and their producing methods are disclosed. These steel parts are useful as gears, cams, bearings and similar high-strength compact steel articles which are required to have wear resistance and strength to withstand fatigue in rolling or rolling-slipping applications. In a steel part formed according to the invention, a fine nitride and/or carbonitride having at least an average grain size of 0.3 &mgr;m or less is dispersed in the contact surface structure; a multi phase structure composed of martensite, which is divided into extremely fine pieces, forming a disordered shape, by the nitride and/or carbonitride, is formed; and a carbide having a grain size of 3 &mgr;m or less is dispersed to increase the hardness of the surface.Type: GrantFiled: June 16, 1999Date of Patent: July 2, 2002Assignee: Komatsu LTDInventors: Takemori Takayama, Naoji Hamasaka
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Patent number: 6398420Abstract: The material of inner ring, outer ring and rolling element is formed by a steel material having a chromium (Cr) content of 5% by weight or more. The material is then subjected to cutting. Thereafter, the material thus cut is subjected to heat treatment so that the surface hardness HRC of the worked material is 58 or more. Subsequently, the worked material is subjected to grinding. A working denatured layer present on the surface of the worked material is then removed. Subsequently, an oxide film comprising chromium atom and iron atom at a ratio (Cr/Fe) of 0.5 or more is formed on the surface of the worked material. Accordingly, it is possible to provide a rolling bearing excellent in corrosion resistance and fretting resistance.Type: GrantFiled: May 31, 2001Date of Patent: June 4, 2002Assignee: NSK, Ltd.Inventors: Susumu Tanaka, Hiroyuki Ito