Abstract: A ball for use in a constant-velocity joint, which is adapted to be interposed between an inner race and an outer race for transmitting rotational power therebetween, is produced by nitriding a surface of a ball made of bearing steel or a material equivalent thereto, and processing the nitrided ball for increased resistance to a crushing load. The nitrided ball is processed for increased resistance to a crushing load by tempering the ball at a temperature ranging from 180 to 230° C. The surface hardness of the ball should preferably be adjusted in the range from HRC 60 to 64.

Abstract: A non-heat treated soft-nitrided steel part respective contents of C, Si, Mn, P, Cr, Ti, V, N, Al, Pb, S and Ca of which are in specific ranges and which satisfies the following formulas (1) to (3). This part can be produced in a process of hot working, machining and soft-nitriding without any prior heat treatment, and has superior properties such as high fatigue strength and wear resistance. Fn1=−141.5(C %)−19.6(Mn %)+1280(N %)+95.6≦60  (1) Fn2=−103.8(C %)+59.1(Mn %)+850.4(N %)+360.9≧350  (2) Fn3=−13.4(C %)−3.45(Mn %)+112.7(N %)+13.

Abstract: A method for high concentration carburizing and quenching of steel is provided which is carried out by a treatment process including the steps of carbonitriding the steel at temperatures of from about 800 to about 880° C., and subsequently quenching the steel at a temperature higher than the carbonitriding temperature. In the carbonitriding step, the steel is treated with carbon concentrations in a carburizing atmosphere taken as about 0.7 to about 1.2% and with 3 to 8% of ammonia gas (NH3) being added, for example. This dissolves network-like carbide in austenite and, when the austenite is transformed into martensite by quenching, distributes the dissolved carbide in the form of granules approximately uniformly in the martensite.

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: In a rolling shaft relatively rolling with respect to rolling members provided in a radial needle roller bearing, the rolling shaft is composed of a steel containing 0.5 to 1.2 wt % carbon and is provided with a surface layer 3a containing 0.05 to 0.4 wt % nitrogen, having Vickers hardness being Hv650 or more through a high frequency quenching performed thereto and a residual austenite being 15 to 40 vol %, and a core portion of the rolling shaft contains 0 vol % of the residual austenite.

Abstract: An inexpensive rolling apparatus improved in resistance to fretting, acoustic performance, resistance to corrosion, life and workability is provided. At least one of an outer member, an inner member and rolling elements of the apparatus is formed of an alloy steel containing 1.5% by weight or less of C, 10% to 20% by weight of Cr, 0.1% to 0.8% by weight of Mn, 0.1% to 1.0% by weight of Si and less than 0.2% by weight of N, particularly, at least one of the outer member, the inner member and the rolling elements is formed of a martensitic stainless steel containing 0.6% by weight or less of C, 10% to 14% by weight of Cr, 0.1% to 0.8% by weight of Mn, 0.1% to 1.0% by weight of Si, less than 0.2% by weight of N, 0.5% by weight or less of Mo, 0.2% by weight or less of V, and Fe and inevitable components as the balance, wherein the relationship between the content of C and that of Cr satisfies C %≦−0.05 Cr %+1.

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: The rolling bearing according to the invention comprises a dense nitride layer formed on the surface layer of the rolling elements and optionally an optimum carbonitride layer formed on the races. In this arrangement, the deterioration of durability due to vibration or impact load during transportation can be prevented, not to mention improvement of stillness. Further, the deterioration of impact resistance required for hybrid bearing can be prevented. The release of pilot pressure and defective of acoustic properties due to electrostatic attraction of dust can be prevented. At the same time, the rolling element of the invention comprises a compound layer having an extremely high hardness formed uniformly, making it possible to finish to a high precision. Moreover, a great effect can be exerted of preventing the change of properties with time at high temperature or the deterioration of acoustic properties under other severe working conditions.

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: A soft magnetic thin film having a compositional formula FeaBbNc, wherein a, b and c each denote atomic percent and B denotes at least one of Co, Ni and Ru, and wherein the compositional range is given by 0<b≦5, and 0<c≦5. The film may exhibit uniaxial anisotropy with a uniaxial anisotropy field strength of 1-5 Oe. The film has a coercivity 2.5-4 Oe or less and a saturated magnetic flux density B25 of at least 16 kG measured at a magnetic field of 25 Oe. The film is produced by subjecting a deposited thin film of the compositional formula to heat treatment at a temperature of 220 to 450° C., within or without magnetic field and, has an average crystal grain size of not more than 50 nm.

Abstract: A stretched mask having a high tensile strength and favorable high-temperature creep properties and free from tape twist, and a material for the stretched mask. A low-carbon steel sheet containing 70 ppm to 170 ppm of nitrogen on a weight basis is heat-treated at a temperature at which recrystallization does not take place. The heat-treated material is provided with a resist pattern for forming apertures and subjected to etching to form apertures.

Abstract: A member used in contact with a hot dip galvanizing bath, such as a sinker roll, a support roll or a bearing, is produced by nitriding stainless steel to form a nitride layer and a nitrogen-diffused layer on the surface thereof. The member used in contact with a hot dip galvanizing bath is formed on its surface with the nitride layer by nitriding it in a salt bath containing a cyanide, a cyanate, a carbonate and the like or by heat-treating it in an atmosphere containing ammonium or nitrogen.

Abstract: There is provided inexpensive maraging steel having high fatigue strength and maraging steel strip formed by use of the same. The maraging steel having high fatigue strength, consisting essentially, by mass, of not more than 0.008% C, from 0 inclusive but not more than 2.0% Si, from 0 inclusive but not more than 3.0% Mn, not more than 0.010% P, not more than 0.005% S, 12 to 22% Ni, 3.0 to 7.0% Mo, less than 7.0% Co, not more than 0.1% Ti, not more than 2.0% Al, less than 0.005% N, not more than 0.0033% O (oxygen), and the balance substantially Fe, a total amount of (3Si+1.8Mn+Co/3+Mo+2.6Ti+4Al) being in a range of 8.0 to 13.0%.

Abstract: A dispersion hardened FeCrAl-alloy and method of its production which includes in one step, forming a nitride dispersion in a FeCr-alloy, whereby this nitride dispersion includes one or more of the basic elements hafnium, titanium and zirconium, and, in a later step aluminum is added to the nitrided FeCr-alloy. The unfavorable formation of aluminum nitrides has thereby been avoided by adding aluminum after the nitriding. A FeCrAl-alloy with high high temperature strength and high creep strength has thereby been achieved.

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: The invention provides a piston ring and piston ring material with excellent properties since not only it has excellent properties as a piston ring, but also excellent in drawability and rolling workability in the manufacturing process of stock, very excellent bending workability can be attained even when relatively high hardness after heat treatment is established, and excellent in properties as a piston ring. The piston ring material essentially consists, by weight of 0.2 to 1.2% C, 5.0 to 25.0% Cr and the balance Fe and incidental impurities, M7C3 type carbide content existing in the structure being 4.0% or less in terms of area percent to attain excellent scuffing resistance and workability. Preferably, C is 0.2 to 0.7%, and Cr is not less than 5.0% but less than 12.0%. Cr (wt. %)/C (wt. %) is 12 to 45, preferably 15 to 45, more preferably 18 to 30. In addition, the piston ring material of the present invention may contain not more than 0.25% Si, not more than 0.30% Mn, at least one not more than 2.

Abstract: The high-strength valve spring uses, as the material, a steel containing 0.5-0.8% C, 1.2-2.5 wt % Si, 0.4-0.8 wt % Mn, 0.7-1.0 wt % Cr, balance Fe and inevitable impurities, where, in the inevitable impurities, Al is no more than 0.005 wt % and Ti is no more than 0.005 wt %, and the largest non-metallic inclusion is 15 &mgr;m. In the oil tempering treatment, the heating temperature at hardening is between 950-1100° C., and nitriding treatment is performed after coiling. It is preferable to nitride at a temperature no lower than 480° C. Since the material is a high-silicon steel, the tempering temperature can be set at a higher temperature, and the nitriding temperature can be so high. In another way, after coiling, the spring is subjected to shot peening at least twice with shot particles of hardness 720 Hv or higher to produce a compressive residual stress of 85 kgf/mm2 at around surface.

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 soft magnetic thin micro-crystalline film of FeaBbNc (at %) wherein B is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b≦20 and 0<c≦22 except the range of b≦7.5 and c≦5, shows low coercivity Hc of 80-400 Am−1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding. This film is produced by crystallizing an amorphous alloy film of the similar composition at 350-650° C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around &lgr;s=0. Composite magnetic head is made using this thin film. Diffusion preventive SiO2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.

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 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 gear having high pitching resistance, sufficient surface hardness, sufficient hardened depth, high abrasion resistance, high breakage resistance, high fatigue resistance, and low gear noises. A material equivalent to JIS-SCM420 is soft nitrided for two hours in a mixture gas containing 45 to 65 volume % of residual NH.sub.3 at a gas temperature of 530 to 565.degree. C., thus producing a compound layer having a hardness equal to or higher than that of the material plus Hv 50 and a thickness of 200 .mu.m or more.

Abstract: The present invention relates to manufacturing methods of nitrided steel parts, having high tensile strength, high fatigue strength, and excellent bending roughness, through nitriding without thermal refining, to thus-manufactured steel parts, and to steel products for nitriding, and steels for nitriding having a specific chemical composition, serving as steel stock for the manufacture of such steel parts. The chemical composition is as follows: C: over 0.20 to 0.60%, Si: 0.05 to 1.0%, Mn: 0.20 to 1.50%, P: 0.08% or less, S: 0.005 to 0.10%, Cu: 0.30% or less, Ni: 0.30% or less, Cr: 0.30% or less, Mo: 0.30% or less, V: 0.20% or less, Nb: 0.05% or less, Ti: 0.003 to 0.03%, Al: 0.08% or less, Ca: 0.005% or less, Pb: 0.30% or less, N: 0.008 to 0.030%, and the balance of Fe and unavoidable impurities. Steel products preferably have the ferrite-pearlite microstructure having a ferrite percentage of not less than 10%.

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: A gear having a high fatigue strength can be produced relatively inexpensively. The gear is produced by plastic working using a steel material containing C.ltoreq.0.01 wt %, Si.ltoreq.1 wt %, 0.05 wt %.ltoreq.Mn.ltoreq.0.5 wt %, P.ltoreq.0.1 wt %, S.ltoreq.0.03 wt %, 0.02 wt %.ltoreq.sol.Al.ltoreq.0.1 wt %, 0.8 wt %.ltoreq.Cu.ltoreq.1.7 wt %, and 0.02 wt %.ltoreq.Ti.ltoreq.0.1 wt %, the balance being Fe and inevitable elements. The gear is subjected to soft nitriding, serving as artificial aging, after a solution treatment. The resulting gear has a sufficiently deep, surface hardened layer. Further, the gear may be produced inexpensively since the simultaneous performance of the artificial aging and soft nitriding saves energy.

Abstract: Magnetic shield materials used in color picture tubes which have excellent inner magnetic shield characteristics and an excellent handling strength, method for producing the materials and color picture tubes produced by incorporating the materials are provided. The magnetic shield materials produced by subjecting hot rolled low carbon steel strips essentially consisting of equal to or less than 0.006 weight % of C, equal to or less than 0.002 weight % of N, equal to or less than 0.5 weight % of Mn, 0.5-2.5 weight % of Si, Fe as a balance and unavoidable impurities to a cold rolling and subsequently annealing the cold rolled steel strip at a temperature of 500-700.degree. C. and applying a nickel plating thereto after annealing.

Abstract: A magnetic pole or magnetic shielding film is constructed of a soft magnetic thin film that has a composition represented by formula (Fe.sub.1-x M.sub.x).sub.1-y N.sub.y wherein M is at least one element selected from the group consisting of magnesium, calcium, yttrium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, and boron, and an atomic ratio x is 0.01.ltoreq.x.ltoreq.0.1 and an atomic ratio y is 0.01.ltoreq.y.ltoreq.0.1. This soft magnetic thin film has a I(200)/I(110) ratio of 0.1 inclusive to 1 exclusive with the proviso that I(200), and I(110) represents an intensity of a diffraction peak for an iron (200) plane, and an iron (110) plane, respectively, as found from an X-ray diffraction pattern, and is substantially free from a diffraction peak for a nitride of the element M, as found from the X-ray diffraction pattern.

Abstract: Forged, nitrided steel parts having a high fatigue limit and bending toughness are produced without heat treatment for refining between the forging and nitriding. The steel has a composition consisting essentially, on a weight basis, of: 0.30-0.60% of C, 0.05-1.50% of Si, 0.20-2.00% of Mn, less than 0.02% of P, less than 0.04% of S, not greater than 0.30% of Cr, less than 0.01% of Al, 0.01-0.02% of N, and a balance of Fe and incidental impurities in which the content of V as an impurity is 0.02% or less. The steel composition may further contain at least one element selected from P: 0.02-0.07%, S: 0.04-0.10%, Ca: 0.0003-0.003%, and Pb: 0.01-0.20% in order to provide it with improved machinability.

Abstract: The invention is embodied in a soft magnetic thin film article comprising an iron--chromium-nitrogen (Fe--Cr--N) based alloy and methods for making such article. The soft magnetic thin film article is formed using an iron--chromium--nitrogen based alloy with tantalum in one embodiment and with at least one of the elements titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), molybdenum (Mo), niobium (Nb) or tungsten (W) in another embodiment. The article is formed such that the alloy has a relatively high saturation magnetization (e.g., greater than approximately 15 kG) and a relatively low coercivity (e.g., less than approximately 2.0 oersteds) in an as-deposited condition or, alternatively, with a very low temperature treatment (e.g., below approximately 150.degree. C.). The inventive films are suitable for use in electromagnetic devices, for example, in microtransformer cores, inductor cores and in magnetic read-write heads.

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: A nitriding steel excellent in formability and susceptibility to nitriding, comprising, based on weight, 0.0002 to less than 0.08% of C, 0.005 to 1.00% of Si, 0.010 to 3.00% of Mn, 0.001 to 0.150% of P, 0.0002 to 0.0100% of N, greater than 0.15 to 5.00% of Cr, greater than 0.060 to 2.00% of Al (Al becoming a selective component in an amount of greater than 0.10 to 2.00% when the C content is from 0.0002 to less than 0.0100%), one or two elements selected from 0.010 to 1.00% of Ti and 0.010 to 1.00% of V, and the balance Fe and unavoidable impurities, and a press formed article formed from the steel and having a hard nitride layer at least on one side.

Abstract: In a rolling bearing in which at least one member of an inner race, outer race and rolling elements is made of an alloy steel containing 0.2 to 1.0 wt % of C, 3.0 to 14.0 wt % of Cr and 0.8 to 3.0 wt % of V, the balance being Fe, the member being carburized or carbonitrided, followed by hardening and tempering to secure that the surface carbon concentration C% and the concentrations Cr%+V% of Cr and V satisfy a relationship of C%.ltoreq.0.13 (Cr%+V%)+1.10 and that carbides existing on a surface of the member have an area fraction of 15 to 50%, the rolling bearing has an extending service life even if it is used under lubrication in the presence of foreign matter and exhibits superior wear resistance to be hard to wear even if there occurs a breakage of oil film.

Abstract: A method of producing high strength steel sheet and formed articles fabricated from the sheet and containing about 0.01-0.3 free and uncombined atomic percent Ti, Nb or V as strengthening element, by hot rolling or hot rolling plus cold rolling the sheet within limited temperature ranges, annealing the rolled sheet or formed articles at a temperature of about 1275.degree.-1350.degree. F. to provide a (111) grain structure, nitriding the annealed sheet or formed article in an annealing furnace at a temperature of about 800.degree.-1250.degree. F. under fully developed laminar gas flow, and controlling the strengthening of the steel article as a function of steel composition, the nitriding gas composition, nitriding time, nitriding temperature, thickness of the steel sheet and depth of strengthening desired, in accordance with specified relationships, to provide a steel article having an 0.2% off-set yield strength after temper rolling of at least about 40 ksi and an r value in excess of about 1.

Abstract: A soft magnetic thin micro-crystalline film of FeT.sub.b N.sub.c (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b<20 and 0<c<22 except the range of b.ltoreq.7.5 and c.ltoreq.5, shows low coercivity Hc of 80-400 Am.sup.-1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding.This film is produced by crystallizing an amorphous alloy film of the similar composition at 350.degree.-650.degree. C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around .gamma.s=0.Composite magnetic head is made using this thin film. Diffusion preventive SiO.sub.2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.

Abstract: At least one of surfaces including the raceway of an inner ring, the raceway of an outer ring, and at least the rolling surfaces of rolling elements is made of a steel containing nitrogen within the range of from 0.2 to 5.0 wt. % and chromium within the range of from 7.0 to 25 wt. %.

Abstract: Loom components such as reed dents or weft brake lamellae that, during operation, are exposed to frictional abrasion by a moving weft thread, are made of cold rolled strip steel or of refined nitrided steels. The components are then exposed to a heat treatment at a temperature larger than 480.degree. C. for a duration of more than two hours, preferably up to 8 hours. A thermo-chemical treatment is performed simultaneously with the heat treatment to harden at least those surface areas of the components that in operation will be exposed to the frictional abrasion.

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 workpiece is made of a steel body and has a hard material coating thereon. The surface which receives the hard material coating is enriched with at least one of C, N, B, O, S or Si. A transition zone between the enriched surface area and the hard material coating has a non-diminishing content of the at least one element.

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.

Abstract: A monolithic metallic drive shaft for a marine propulsion device is disclosed which is resistant to corrosion. The drive shaft comprises proximal and distal end portions, each of which has a predetermined surface hardness. The surface hardness of one of the proximal and distal end portions is greater than the surface hardness of the other of the proximal and distal end portions.

Abstract: The present invention resides in a method for making an internal combustion engine intake valve. An iron aluminum alloy, in the form of a coil or bar stock, is provided. The alloy comprises 76.05 to 90.15 weight percent iron, 9 to 13.3 weight percent aluminum, 0.05 to 0.35 weight percent carbon, and 0.5 to 3 weight percent of a refractory metal, and/or 0.3 to 1.5 weight percent of titanium in combination with, or in place of, the refractory metal. The coil or bar stock is extruded to a poppet valve preform configuration at a heading temperature in the range of 800.degree. to 2,000.degree. F. and a true strain of about 0.5 to 2.2. The preform configuration is then headed to a pre-machined configuration while maintaining the head of such preform at an effective heading temperature up to 2,200.degree. F. said heading being carried out at a true strain of about 1.4 to 2.3.

Abstract: The surface layer of a hard austenitic stainless steel screw is formed as nitrided layer and then is covered by a plating coat or a resin coat to give properties such as shortening the boring time as well as heightening the surface hardness of the screw itself.

Abstract: Nitrided stainless steel products having a base material of stainless steel containing austenitic stainless steel. At least a portion of the surface layer of the base material is composed of a nitrided hard layer in accordance with the following conditions (A) and (B):(A) the nitrided hard layer substantially does not contain crystalline chromium nitride, and(B) the nitrided hard layer contains from 2 to 12% by weight N atoms.

Abstract: The soft magnetic thin film of the invention has an atomic ratio composition of the formula:[(Fe.sub.1-y Ni.sub.y).sub.1-x M.sub.x ].sub.1-z N.sub.zwherein M is at least one member selected from the group consisting of Mg, Ca, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, and B, 0.001.ltoreq.x.ltoreq.0.15, 0.ltoreq.y.ltoreq.0.1, and 0.001.ltoreq.z.ltoreq.0.15, and has a relative intensity ratio of Fe (200) peak to Fe (110) peak in an X-ray diffraction spectrum of at least 1/3 and high Fe (100) orientation. It has excellent soft magnetic properties in that it has a high saturation magnetic flux density Bs, heat resistance, a low coercive force Hc, and a high magnetic permeability .mu.. A magnetic head using such a thin film has improved otherwise properties, recording/reproducing sensitivity, and electromagnetic properties, and is highly reliable.

Abstract: The present invention provides a steel sheet for press working that exhibits excellent stiffness and satisfactory press workability. The steel sheet for press working includes: a composition of C+N+B=0.007 to 1.0 wt % in a region from the surface of the steel sheet to a position of 5% of the thickness in a direction of the thickness in at least either of the surface layers; a pole intensity of [{321}+{211}]/{100}.gtoreq.1.2 in a vertical direction to the sheet surface realized at a 3% thickness position in the direction of the thickness from the surface; and a composition of C+N+B=0.010 wt % less than in the central portion 40% except for two 30% portions of the two surface layers in the direction of the thickness.

Abstract: Method for the treatment of alloy steels and refractory metals such as Ti, Zr and Nb, especially for depassivation and subsequent thermochemical surface treatment in a process chamber (1, 2) under the action of pressure and temperature, wherein, in a first process step, a first gas or gas mixture from the group N.sub.2, H.sub.2 or NH.sub.3 is admitted for the depassivation into a process chamber (1), a pressure greater than 1 bar a and a temperature between 100.degree. C. and 1,000.degree. C. is established in the chamber (1), and in a second process step a second gas or gas mixture from the group of N-, C- or B-containing gases is admitted into a process chamber (1, 2) for the thermochemical surface treatment, and a temperature between 100.degree. C. and 1,000.degree. C. at a pressure greater than or equal to 1 bar a is established.

Abstract: An object of this invention is to provide a rolling bearing which is increased in rolling fatigue life when used with a lubricant contaminated by foreign matters, and which is improved in wear resistance and in seizure resistance. In a rolling bearing, at least one of the inner race, outer race and rolling elements thereof is made of an alloy steel which contains 0.10 to 1.0 wt of C, 0.50 to 3.0 wt % of Cr, 0.10 to 2.0 wt % of Mo, 0.15 to 1.0 wt % of Si, 0.20 to 1.5 wt % of Mn, and 0.2 to 1.0 wt % of Ni, and which is carbo-nitrided so that the sum (C+N) of the contents of carbon (C) and nitrogen (N) in the surface layer thereof is 1.0 to 2.0%, and the ratio (N/C) of the content of nitrogen (N) to the content of carbon (C) is 0.8 to 2.0.

Abstract: In order to provide a ball-and-roller bearing that has a longer life and which exhibits higher reliability than the prior art products not only under lubrication in the presence of foreign matter but also under lubrication in clean conditions, according to the present invention, a bearing material that contains 0.2 to 1.0 wt % of carbon and at least 1 wt % in total of one or more elements selected from among chromium, molybdenum and vanadium is subjected to a carbonitriding treatment and a hardening heat treatment to make an alloy steel in which the area ratio of carbonitrides present in the surface layer of said bearing material per unit area is adjusted to be at least 10%, a maximum grain size of carbonitrides present in said surface layer being no more than 3 .mu.m, the content of retained austenite (.gamma..sub.R) in said surface layer being 25 to 45 vol %, and said surface layer having a surface hardness of at least 750 Hv.

Abstract: The present invention resides in a method for making an internal combustion engine intake valve. An iron aluminum alloy, in the form of a coil or bar stock, is provided. The alloy comprises 76.05 to 90.15 weight percent iron, 9 to 13.3 weight percent aluminum, 0.05 to 0.35 weight percent carbon, and 0.5 to 3 weight percent of a refractory metal, and/or 0.3 to 1.5 weight percent of titanium in combination with, or in place of, the refractory metal. The coil or bar stock is extruded to a poppet valve preform configuration at a heading temperature in the range of 800.degree. to 2,000.degree. F. and a true strain of about 0.5 to 2.2. The preform configuration is then headed to a pre-machined configuration while maintaining the head of such preform at an effective heading temperature up to 2,200.degree. F., said heading being carried out at a true strain of about 1.4 to 2.3.

Abstract: A magnetic alloy film suitable for high density recording has a composition of (Fe.sub.x M.sub.y N.sub.z).sub.a L.sub.b, where L is Cu and/or Ag. The provision of Cu and/or Ag in a range from 0.5 to 5 atomic % enhances thermal stability of the soft magnet properties of the alloy.