Abstract: A heat resistant carburized rolling bearing component is formed of a steel material at least containing, as alloy elements in a matrix, by mass %, at least 0.1% and at most 0.4% of C, at least 0.3% and at most 3.0% of Si, at least 0.2% and at most 2.0% of Mn, at most 0.03% of P, at most 0.03% of S, at least 0.3% and less tan 2.5% of Cr, at least 0.1% and less than 2.0% of Ni, at most 0.050% of Al, at most 0.003% of Ti, at most 0.0015% of O and at most 0.025% of N, and a remaining part of Fe and an unavoidable impurity, and the bearing component is prepared by performing carburizing-carbo-nitriding process followed by quenching, and after quenching, tempering at a tempering temperature of at least 200° C. and at most 350° C., and surface hardness after tempering process is at least HRC57.

Abstract: 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 and tools 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 tools.

Abstract: The base material consists of a base steel having a base carbon content of less than 0.3 wt % carbon and enriched with carbon starting from its surface 2,3,4 formed of formed of two broad surfaces 2, two short edge sides 3 and two long edge sides 4. The base steel has boundary areas 5 enriched with 0.5-1.1 wt % carbon starting from at least one broad surface 2 and transforming with a decreasing carbon content into an area 6 not enriched with carbon or only slightly enriched. At the edge surface 3,4, the base material has the sandwich structure formed of the carbon-enriched boundary area 5 and the area 6 not enriched with carbon. (FIG.

Abstract: 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.

Abstract: As a steel material for an inner race, an outer race and a rolling element constituting a rolling bearing, there is used one containing carbon (C) and chromium (Cr) in an amount of 0.65 wt % to 1.10 wt % and 2.0 wt % to 6.0 wt %, respectively. At least one of the inner race, the outer race and the rolling element is formed from the steel material. The inner race, outer race and the rolling element thus formed is then subjected to hardening, tempering and polishing. Further, a chromium oxide layer (Cr2O3) having a thickness of 5 nm to 300 nm is formed on a race track surface of at least one of the inner race, the outer race and the rolling element. If the rolling bearing is used in operation under the lubrication at a high traction coefficient with water mixed therein, finely particulate molybdenum carbide and/or vanadium carbide having a particle diameter of 50 nm to 300 nm is distributed in the matrix.

Abstract: A rolling bearing contains no more than 0.3 wt % of nitrogen in a grinding allowance portion after carbonitriding and hardening heat treatments, contains from 0.9 wt % (inclusive) up to 1.6 wt % (inclusive) of carbon and from 0.05 wt % (inclusive) up to 0.3 wt % (inclusive) of nitrogen in the surface layer of the finished part and has a nitrogen gradient of no more than 0.5 wt %/mm in the surface layer of the finished part. The rolling bearings are improved in grinding efficiency and which have their rolling life extended significantly.

Abstract: Steel compositions and processes are described that provide optimum resistance to austenite grain coarsening in cold-formed and carburized components for automotive and machine structural applications. The steel compositions include, in weight percent, 0.1-0.3% C 150-220 ppm N and a grain refining addition selected from the group consisting of Al, V plus Al and Nb plus Al, the balance comprising iron and other alloying elements typically found in carburizing grades of steel. The steels are processed by reheating to a temperature in the vicinity of solution temperature of the least soluble species of grain refining precipitate and then hot worked. The hot-worked steel is cooled at an accelerated rate to 500° C. and then subcritically annealed, cold formed in at least one operation with intermediate anneals subcritically annealed after the last cold-forming operation, and carburized quenched and tempered (6).

Abstract: For easily producing a toothed material for high-strength gears etc. with a plastic working technique, deformation resistance occurring in plastic working is reduced and stable high precision plastic working is enabled at lower temperatures. One or more types of heat treatment selected from carburization, carbonitriding and nitriding and a hardening process are applied to an alloy steel material containing: iron as a main component; at least 1.0 to 4.5 wt % Si; 0.35 wt % or less C; and balance Fe and unavoidable impurities, whereby a rolling element is obtained which has a surface layer mainly composed of martensite containing no &agr;-Fe phase and of residual austenite and an inner structure cooled from an (&agr;+&ggr;)-Fe two phase region.

Abstract: In a rolling bearing having a rolling bearing ring and a rolling element of at least 20 mm in diameter, at least one of the rolling bearing ring and the rolling element consists of carburized or carbonitrided steel containing at least 0.2 wt % and not more than 0.35 wt % of carbon and at least 2.2 wt % and not more than 3.6 wt % of Ni. Thus obtained is a rolling bearing capable of reducing the material cost and increasing the fatigue life or reducing the carburizing time by ensuring surface hardness and optimizing the case depth.

Abstract: 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.

Abstract: In a rolling bearing having a rolling bearing ring and a rolling element of at least 20 mm in diameter, at least one of the rolling bearing ring and the rolling element consists of carburized or carbonitrided steel containing at least 0.2 wt % and not more than 0.35 wt % of carbon and at least 2.2 wt % and not more than 3.6 wt % of Ni. Thus obtained is a rolling bearing capable of reducing the material cost and increasing the fatigue life or reducing the carburizing time by ensuring surface hardness and optimizing the case depth.

Abstract: 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 %].

Abstract: A rolling or sliding part is produced from a blank of steel material subjected to a heat treatment including carburization and thereby made to contain a spheroidal carbide precipitated and dispersed in a carburized layer matrix. The particle-to-particle distance of the spheroidal carbide is up to 15 &mgr;m in terms of the distance between the most proximate particles. The rolling or sliding part is suitable as antifriction bearing components, such bearing rings and rolling bodies, or as sliding bearing components, for use in soiled oil containing extraneous matter. The antifriction bearing comprising this part serves a lengthened rolling life in soiled oil and clean oil, and the sliding bearing incorporating the part is also given an extended life.

Abstract: A ball-and-roller bearing is disclosed having an inner ring, an outer ring arranged on the axis of the inner ring and rotating around the co-axis relative to the inner ring, and a rolling body interposed between the inner ring and the outer ring and rolling with rotation of the outer ring relative to the inner ring. One of the inner ring, the outer ring, and the rolling body has a core member made from an alloy containing iron, at least one of 0.2 to 1.0% by weight of silicon and 0.2 to 1.5% by weight of manganese, 7.0 to 11.0% by weight of chromium, 1.5 to 6.0% by weight of molybdenum, and 0.5 to 8.0% by weight of cobalt, and a case hardened surface layer. Also disclosed is the method of manufacturing the bearing by forming a core member of the alloy, forming a case hardened layer containing 0.9 to 1.

Abstract: A rolling bearing having a plurality of rolling elements located between a fixed race and a rotating race, wherein at least one of bearing components comprising the fixed race, rotating race and rolling elements is made of a steel which contains from 0.05 to 0.40% by weight of at least one selected from the group consisting of Ti, Nb and Al along with from 0.65 to 1.20% by weight of C, from 0.05 to 0.70% by weight of Si, from 0.2 to 1.5% by weight of Mn, from 0.15 to 2.0% by weight of Cr, not more than 01.01% by weight of N and unavoidable contaminating elements and wherein particles of at least one of Ti carbide, Ti carbonitride, Nb carbide, Nb carbonitride and Al nitride are dispersed and deposited at least in the vicinity of the surface of the at Least one of bearing components.

Abstract: This invention provides a covered member which possesses a high bond strength of a base material and a covering film, and has a smooth surface. The covered member comprises a base material and a covering film and the surface of the base material to be covered with the covering film is characterized by an uneven surface having projections with an average height in the range from 10 to 100 nm and an average width of not more than 300 nm. The uneven surface can be formed by ion impacting. A surface of a covering film formed on that is smooth since the unevenness of the surface is extremely fine.

Abstract: A rolling bearing including a rolling bearing ring and a rolling element, at least one of the rolling bearing ring and the rolling element consisting of carburized steel containing at least 0.3% and at most 0.6% of C, at least 0.1% and at most 0.35% of Si, at least 1.1% and at most 1.5% of Mn, at least 0.5% and at most 2.0% of Cr, at least 0.2% and at most 0.6% of Ni and at least 0.15% and at most 0.5% of Mo by weight. Thus, an inexpensive and long life carburized steel rolling bearing can be obtained using a combination of chemical components of a relatively low cost.

Abstract: 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.

Abstract: Disclosed is a rolling bearing comprising an inner race, an outer race, and a plurality of rolling elements, at least one of the inner race and the outer race being formed of an alloy steel which comprises: 0.7≦C≦0.9% by weight; 0.1≦Si≦0.5% by weight; 0.5≦Mn≦1.1% by weight; and 0.1≦Cr≦0.6% by weight; and including, in its surface layer, at least one of 0.8≦C≦1.4% by weight and 0.01≦N≦0.3% by weight. The rolling bearing can be obtained at an extremely low cost and has a long life in a severe environment particularly under contaminated lubrication.

Abstract: A selectively case hardened steel article by low temperature carburization includes a body made of a chromium bearing nickel or ferrous based alloy (for example, stainless steel), a first portion of the body having a first hardness characteristic, and a second portion of the body having a second hardness characteristic; the second portion being less than the entire body and substantially free of carbides. One method for selective case hardening by low temperature carburization includes the steps of applying a carbon blocking mask over surface areas of the article that are not going to be carburized; activating those surface areas that are to be carburized; diffusing carbon into the activated surface areas at a temperature below which carbides readily form; and removing the carbon blocking mask.

Abstract: A method for shot peening a hard metal product that has a hardened surface. The method includes projecting shot on the hardened surface of the hard metal product. The ratio of the Vickers hardness of the shot to that of the hardened surface is 0.8-1.6, and the diameter of the shot is 30-250 .mu..

Abstract: A method for the heat treatment of steel, comprising carburization hardening said steel, to form carburized steel, followed by a second hardening, reduces the grain size of steel while precipitating carbonitrides inside the grains of steel, thereby increasing the strength of the heat-treated steel. The carburization hardening comprises heating the steel to a first austenitic temperature range in an atmosphere comprising a carburizing gas and optionally ammonia, cooling the steel to a martensitic temperature range, and quenching the steel, and the second hardening comprises heating the carburized steel to a second austenitic temperature range in an atmosphere comprising a carburizing gas and ammonia, and quenching the steel.

Abstract: A carburizing steel having the following chemical composition:C: 0.1 to 0.25%,Si: 0.2 to 0.4%,Mn: 0.3 to 0.9%,P: 0.02% or less,S: 0.001 to 0.15%,Cr: 0.5 to 0.9%,Mo: 0.15 to 1%,Al: 0.01 to 0.1%,B: 0.0005 to 0.009%,N: less than 0.006%, andthe balance of Fe and incidental impurities, wherein % is on a weight basis. Also disclosed are a method for the manufacture of the carburizing steel, parts of constant velocity universal joints for drive shafts made of the carburizing steel, as well as a method for the manufacture of such parts. The carburizing steel may further contain Ni: 0.3-4.0%, and one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each. The parts of constant velocity universal joints for drive shafts are manufactured using the carburizing steel of the present invention as a material. When they are carburized and quenched, they exhibit a surface hardness (Hv) of 650-800, core hardness (Hv) of 250-450, and carburized case depth of 0.2-1.2 mm.

Abstract: A method for case hardening a chromium bearing nickel or ferrous based alloy, for example stainless steel, article, the method including the steps of activating the surface of the article; and carburizing the activated surface at a temperature below that temperature which would promote the formation of carbides. In one embodiment the surface is activated by disposing a layer of iron over the surface of the article.

Abstract: Process for manufacturing a mechanical component made of steel, in which a blank of the steel component is manufactured and a high-temperature carburizing or carbonitriding treatment of at least part of the surface of the blank of the component is carried out, the chemical composition of the steel of which the component is composed comprises, by weight: 0.15%.ltoreq.C.ltoreq.0.35%; 0%.ltoreq.Si.ltoreq.0.6%; 0%.ltoreq.Mn+Cr+Ni+Mo.ltoreq.5%; 0%.ltoreq.Al.ltoreq.0.1%; 0%.ltoreq.Cu.ltoreq.0.5%; 0%.ltoreq.Ti.ltoreq.0.05%; 0.004%.ltoreq.N.ltoreq.0.02%; 0%.ltoreq.S.ltoreq.0.15%; P.ltoreq.0.03%; optionally, up to 0.02% tellurium, up to 0.04% selenium, up to 0.07% lead, up to 0.005% calcium, the balance being iron and impurities resulting from the smelting; the chemical composition being adjusted so that the Jominy curve of the steel is such that: 45 HRC.ltoreq.J.sub.3 .ltoreq.50 HRC; 39 HRC.ltoreq.J.sub.11 .ltoreq.47 HRC; 31 HRC.ltoreq.J.sub.25 .ltoreq.40 HRC; the average values J.sub.3m, J.sub.11m and J.sub.

Abstract: Improved input and output discs for toroidal type continuously variable transmissions are obtained by select processing techniques to form hardened layers. Processing techniques include, e.g., carburizing, carbonitriding, and high-frequency induction hardening. Shot peening may be used to impart compressive residual surface stress to predetermined disc portions to enhance resistance to cracking.

Abstract: Induction hardening of heat treated gear teeth which includes the steps of rough and finish cutting the gear teeth, or alternatively cutting the gear teeth to their final configuration utilizing a one cut method, carburizing the gear and in particular, the gear teeth, slow cooling, or alternatively drawing back the gear so the gear teeth are not hard, and induction hardening the gear teeth heating only the surface of the gear teeth. This results in improved strength for the gear teeth as a result of increased residual compressive stresses therein. Induction heating of only the surface of the gear teeth results in an relatively low case depth in the root of the gear teeth.

Abstract: A wear resistant, diamond enhanced cutting tool for excavating is disclosed. The cutting tool includes a cutting insert having a diamond coated cutting tip brazed to the cutting insert. The cutting tool is formed by brazing the insert to a tool body with a braze alloy by heating the insert and tool body to a temperature at which the braze alloy melts. The insert and tool body are then cooled to solidify the braze alloy and quenched to cause a martensitic transformation. Finally, the diamond enhanced tip is brazed to the insert while the temperature of the tool body is maintained below a temperature at which the tool body would soften. According to this method, the cutting tool is formed without creating a tempered zone of reduced hardness.

Abstract: The invention relates to a power roller used for a toroidal-type continuously variable transmission. This power roller has on its first side a groove for receiving a bearing, and the surface of the groove (bearing surface) has a carbon concentration which is not lower than that of the back surface of a second side opposed to the first side. The power roller has a hardened outer layer having first and second portions which are respectively defined by the bearing surface and the back surface. The first portion of the hardened outer layer has an effective depth which is not shallower than that of the second portion thereof. The power roller is prepared by the sequential steps of surface-hardening, quenching, and grinding. The surface-hardening process is one of carburizing and carbonitriding.

Abstract: A surface-hardened chain comprises a plurality of connected chain links, each of which links is made from a killed steel having a specified chemical composition and comprises a surface-hardened layer of a high carbon tempered martensite structure and a core layer of a low carbon tempered martensite structure.

Abstract: A rotating shaft 4 is attached to an inner race 1, and an outer race 2 is fixed to a housing 5 so that the bearing is operated by the rotation of the rotating shaft 4. In this case, the inner race 1 is made to be the race on the rotating side, and the outer race 2 is made to be the race on the non-rotating side. The raw material composing the inner race 1, outer race 2 and rollers 3 is manufactured from alloy steel containing 4.5 weight % or less of Ni, and 0.5 weight % or less of Cu, and the average value of the Cu equivalent of the rollers 3 and the inner race 1 is set at a value higher than the Cu equivalent of the outer race 2. Thus, even in humid environments where water infiltrates into the lubricant, it is possible to make the rolling bearing have the same durable life as with rolling bearings which are used in normal environments.

Abstract: Disclosed is a rolling bearing comprising races and rolling elements, in which at least one of the races and the rolling elements has at least one of a carbide and a carbonitride precipitated in a surface layer thereof, inclusive of a cutting allowance, wherein the finished surface of at least one of the races and the rolling elements has a hardness of Hv600 to Hv700 at 300.degree. C. The rolling bearing has reliable wear resistance under severe conditions and thereby having an extended bearing life.

Abstract: A bearing steel part for a rolling bearing having a core portion and a high hardness region formed by carburization to cover the core portion is provided in which the composition of at least the core portion contains at least 0.15 wt. % and at most 0.20 wt. % of C, at least 4 wt. % and at most 7 wt. % of Cr, at least 1 wt. % and at most 3 wt. % of Mo, and at least 0.4 wt. % and at most O.9 wt. % of V, with Fe group as base material. Therefore, the bearing steel part for the rolling bearing can be obtained having a better rolling contact fatigue life realized by increasing the core hardness of carburized steel and also having a high fracture toughness value.

Abstract: A steel article is formed of a steel material containing from about 0.08 to about 0.35 carbon and is characterized by having a plurality of carbides dispersed on at least one pre-selected surface area of the article, with the surface carbides being dispersed within a predominantly lower bainitic matrix. A method for forming the steel article having high hardness and higher toughness includes carburizing the article at a temperature and for a period of time, in an atmosphere having a carbon potential, sufficient to form carbides and austenite on at least one preselected surface of the article, and then quenching the carburized article to a temperature below the Ar.sub.1 temperature and above the M.sub.s temperature of the steel material for a time sufficient to transform a major portion of the austenite in the preselected surface area microstructure to lower bainite.

Abstract: In order to provide rolling bearings of high performance using case hardened stainless steels that are superior to the conventional martensite base stainless steels in terms of corrosion resistance, rolling fatigue strength and wear resistance and which also have high core toughness, at least one member of the rolling bearing selected from among the inner race, the outer race and the rolling elements is made of an alloy steel consisting essentially of less than 0.5 wt % C, 8.0 to 20.0 wt % Cr, 0.1 to 1.5 wt % Mn, 0.1 to 2.0 wt % Si and the balance of Fe and incidental impurity elements; the relationship between the C and Cr contents satisfies 0.04 Cr (wt %)-0.39.ltoreq.C (wt %).ltoreq.-0.05 Cr (wt %)+1.41; the bearing also has a surface layer that is formed by nitriding or carbonitriding at a temperature below Ac.sub.1, subsequent heating at a temperature of 900.degree. to 1,200.degree. C., hardening, a subzero treatment and tempering.

Abstract: There is provided a nickel-base alloy with service enhanced strengthening properties. When exposed to ethylene pyrolysis conditions, namely a carbon containing environment and at temperatures of at least about 900.degree. C., the alloy forms M.sub.6 C and MC carbides that strengthen the alloy. The alloy may be formed into internally finned tubing.The alloy includes about 0.08-0.11% carbon, 41-45% nickel, 23-26% chromium, 0.6-0.95% manganese, 1-1.7% silicon, 0.2-0.6% titanium, 0.25-0.55% aluminum, 1.3-1.7% molybdenum, 0.25-0.6% niobium, 0.15-0.45% tantalum, 0-0.2% tungsten, 0.001-0.005% boron, 0.01-0.03% zirconium, and the balance iron with trace commercial impurities.

Abstract: A carburizing steel having the following chemical composition:C: 0.1 to 0.25%,Si: 0.2 to 0.4%,Mn: 0.3 to 0.9%,P: 0.02% or less,S: 0.001 to 0.15%,Cr: 0.5 to 0.9%,Mo: 0.15 to 1%,Al: 0.01 to 0.1%,B: 0.0005 to 0.009%,N: less than 0.006%, andthe balance of Fe and incidental impurities, wherein % is on a weight basis. Also disclosed are a method for the manufacture of the carburizing steel, parts of constant velocity universal joints for drive shafts made of the carburizing steel, as well as a method for the manufacture of such parts. The carburizing steel may further contain Ni: 0.3-4.0%, and one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each.

Abstract: A stainless steel bearing component containing in excess of 11% chromium and between 0.05% and 0.50% carbon is case-hardened by introducing carbon or nitrogen into the surface of the race using a plasma process. The component is heated in a chamber from which air is evacuated. There it is bombarded with hydrogen ions to clean its surface. Next, while the component remains at an elevated temperature, a gas containing carbon or nitrogen or both is introduced into the chamber where it exists at a relatively low pressure on the order of 2-9 torr. A plasma is produced intermittently, and it causes carbon or nitrogen or both to diffuse intio the surface of the component and create a case containing a greater proportion of carbon or nitrogen than the underlying core. Thereafter, the component is cooled and with most stainless steels this may be acheived by quenching in oil.

Abstract: A composite magnetic member formed of a single material having a ferromagnetic section with high soft magnetism and a non-magnetic or the like section with sufficiently low magnetic (feebly magnetized or non-magnetic) and sufficient low MS temperature and a process for producing the member are provided. A composite magnetic member made of a single material of martensitic stainless steel including Ni having two sections of a ferromagnetic section having maximum permeability not less than 200 and coercive force not more than 2000 A/m and a feebly magnetized section having permeability not more than 2 and MS temperature not more than -30.degree. C.

Abstract: A method of carburizing austenitic stainless steel comprising the steps of holding austenitic stainless steel in a fluorine- or fluoride-containing gas atmosphere with heating prior to carburizing and carburizing the austenitic stainless steel at a temperature not more than 680.degree. C. wherein said austenitic stainless steel is stable austenitic stainless steel having 1 to 6 weight % molybdenum or 13 to 25 weight % chromium, wherein a carburized hard layer having corrosion resistance superior to base material forms and austenitic stainless steel products obtained thereby.

Abstract: Steel for forming a gear by carburizing and quenching consisting essentially of: 0.1 to 0.35 wt. % C, 0.5 to 2.5 wt. % Si, 0.2 to 2.5 wt. % Mn, 0.01 to 2.5 wt. % Cr, 0.01 to 0.7 wt. % Mo, and the balance being Fe and inevitable impurities. The steel has an Ac.sub.3 point parameter (Ac.sub.3) and an ideal critical diameter (D.sub.I), the Ac.sub.3 point parameter being in a range of 850.degree. to 960 .degree. C., the ideal critical diameter (D.sub.I) being in a range of 30 to 250 mm, and the Ac.sub.3 point parameter (Ac.sub.3) and the ideal critical diameter (D.sub.I) being defined by the following equations.Ac.sub.3 =920-203.sqroot.C+44.7 Si+31.5.times.Mo-30.times.Mn-11.times.CrD.sub.I =7.95.sqroot.C(1+0.70.times.Si) (1+3.3.times.Mn)(1+2.16.times.Cr) (1+3.0.times.Mo)The steel has a non-carburized portion after carburizing and quenching, an internal structure of the non-carburized portion comprising a dual phase of martensite and ferrite, said ferrite having an area percentage of 10 to 70% in the dual phase.

Abstract: A magnetically soft, Co--Fe--C alloy is disclosed which contains in weight percent, about______________________________________ Carbon 0.05-0.50 Manganese 0.5 max. Silicon 0.5 max. Phosphorus 0.01 max. Sulfur 0.01 max. Chrominum 1.0 max. Nickel 1.0 max. Molybdenum 0.25 max. Cobalt 14-28 Vanadium 0.1 max. Niobium 0.1 max. Tungsten 0.1 max. ______________________________________and the balance is essentially iron. The alloy provides a yield strength of up to about 580 MPa (84 ksi) while maintaining ductility and magnetic induction comparable to the known 27Co--Fe soft magnetic alloy. Magnetic and mechanical properties are developed through an annealing heat treatment which is performed after the alloy has been mechanically worked and machined to final shape.

Abstract: A toroidal type continuously variable transmission includes an input disk mounted on an input shaft; an output disk mounted on an output shaft; and a pair of power roller bearings each of which includes an inner race, an outer race, and a plurality of rolling elements. The inner races are engaged with the input and output disks to transmit the power of the input shaft to the output shaft. The inner races, outer races, input disk and output disk are made of case hardening steel, and are each subjected to a heat treatment in which carburizing or carbonitriding, hardening and tempering are performed sequentially, and then to shot peening, and finished by grinding of a predetermined grinding portion.

Abstract: A nitrocarburization treatment for steel components, such as steel balls or ball bearings is disclosed. In the process, the balls are treated in a nitrocarburizing environment and then reoriented, either inside or outside of that environment to form an epsilon iron nitride layer having some thickness over the entire surface of the ball and no bare spots. The reorientation process minimizes superficial metal flow at the surface of the balls and achieves consistent corrosion resistance of at least 96 hours in salt fog tests. Further, components that are cooled in a non-oxidizing environment and then reoriented prior to being returned to the nitrocarburizing environment develop a greater porous layer depth, which provides excellent oil retention for tribological applications.

Abstract: In order to keep down soot production and to enable every part of the workpiece, including deep concavities to be uniformly carburized by vacuum carburizing, and to enable decreases in the quantities of gas and heat employed, carburizing treatment is performed in the heating chamber 2 of a vacuum carburizing furnace 1 with workpieces M being heated while acetylene gas is supplied from a carburizing gas source C inside the heating chamber 2, and the inside of the heating chamber 2 being evacuated by a vacuum evacuation source V to give a vacuum of .ltoreq.1 kPa.

Abstract: In a rolling bearing including an inner race, an outer race and a plurality of rolling elements in which at least one member of the inner race, the outer race and the rolling elements is made of an alloy steel containing: 0.1 to 0.7 wt % of C; 0.8 to 2.0 wt % of V; 0.5 to 3.0 wt % of Cr; 0.3 to 1.2 wt % of Mn; 0.3 to 1.5 wt % of Si; at most 3.0 wt % of Mo; and the balance being Fe, the member being carburized or carbonitrided so that the member has a surface carbon concentration of 0.8 to 1.5 wt % and a surface concentration ratio V/C of 1 to 2.5 in order to cause VC-type carbides to be precipitated on a surface of the member, the rolling bearing exhibits improved wear resistance under a severe condition such as a high-temperature environment and simultaneously the rolling bearing has superior productivity.

Abstract: The use of a chromium-containing martensitic alloy for plastic molds is described. The use properties of a thermally treated plastic mold of a hardness of at least 45 Rockwell C are improved by an iron-based alloy including, in weight-%,______________________________________ C 0.25 to 1.0, preferably 0.4 to 0.8; N 0.10 to 0.35, preferably 0.12 to 0.29; Cr 14.0 to 25.0, preferably 16.0 to 19.0; Mo 0.5 to 3.0, preferably 0.8 to 1.5; and V 0.04 to 0.4, preferably 0.05 to 0.2, ______________________________________where the sum of the concentration of carbon and nitrogen results in a value of, in weight-%, at least 0.5 and no more than 1.2, preferably at least 0.61 and no more than 0.95, the remainder including iron and melt-related impurities.

Abstract: In a rolling bearing including an inner race, an outer race and a plurality of rolling elements in which at least one member of the inner race, the outer race and the rolling elements is made of a high carbon steel material and has a Rockwell hardness of H.sub.R C 60 or more, the high carbon steel material including, in a surface thereof, solid solution of carbon C and solid solution of nitrogen N which are adjusted to satisfy relationships of 0.8 wt %.ltoreq.C.ltoreq.1.2 wt % and 0.1 wt %.ltoreq.N.ltoreq.0.5 wt % with the balance Fe, and in which the retained austenite existing in the high carbon steel material is adjusted to substantially 0 wt %, the rolling beating exhibits superior dimensional stability and high endurance even when it is used under high-temperature conditions, and exhibits high productivity with low cost.

Abstract: A steel for gears consists essentially of 0.10-0.30 wt % of C, not more than 1.0 wt % of Si, not more than 1.0 wt % of Mn, 1.50-5.0 wt % of Cr, and balance including iron and impurity. A gear made by the steel forms a hardened surface layer by carbonizing-hardening-tempering or carbonitriding-hardening-tempering. The amount of C at the hardened surface layer is within a range 0.7 to 1.3 wt %, and the amounts of C, Si and Cr satisfies a relationship 5.5<3.times.C (wt %)+5.2.times.Si (wt %)+Cr (wt %). Therefore, the gear performs superior pitting-resistance and wear-resistance.

Abstract: A manufacturing method of case-hardened parts whose chemical components comprising especially Fe, C, Si, Mn, S, Ni, Mo, Al, V and N including a step of the heat treatment 1 in which, after carburizing, carbonitriding or carburizing followed by carbonitriding steel is cooled gradually at a temperature less than 100.degree. C./minute, by another step of the heat treatment 2, in which steel is heated to a temperature higher than the Ac.sub.3 transformation point and less than 850.degree. C. and kept at the above temperature before quenching, or after keeping at the temperature, is cooled down to a level not below 600.degree. C. before quenching, or quenching is done after cooling down to and keeping the temperature not below 600.degree. C. is disclosed. This method makes the surface layer a mixture of martensite and retained austenite. Thus the case hardened steel products of high precision and high strength are obtainable.