Abstract: Provided is a high-strength stainless steel spring exhibiting a good workability and having a high load characteristic. Thus, the high-strength stainless steel spring of the invention has an chemical component containing 0.04 to 0.08% by mass of C, 0.15 to 0.22% by mass of N, 0.3 to 2.0% by mass of Si, 0.5 to 3.0% by mass of Mn, 16 to 20% by mass of Cr, 8.0 to 10.5% by mass of Ni, 0.5 to 3.0% by mass of Mo, and the balance of Fe and inevitable impurities, and when the average diameter of the coil is represented by D and further the diameter of the steel wire is represented by d in the case that cross sections of the stainless steel wire are in a complete round form or the value obtained by subtracting the average coil diameter from the outer diameter of the coil is represented by d? in the case that the cross sections of the stainless steel wire are in a form other than the complete round form, the spring has a spring index D/d or D/d? of 2 to 6.

Abstract: An exhaust gas guide assembly with an improved high-temperature wear resistance, oxidation resistance, high-temperature strength or the like for a VGS turbocharger is provided. According to the invention, the exhaust gas guide assembly for a VGS turbocharger includes adjustable blades, a turbine frame and an adjusting mechanism is characterized in that a heat resisting member constitutes the exhaust gas guide assembly to remarkably enhance high-temperature durability or the like of the exhaust gas guide assembly.

Abstract: A manufacturing method of an endless metal belt having metal rings built up and differing in circumference, includes the following steps of: a first circumference correction step of expanding each of the metal rings; and a second circumference correction step of expanding each of the metal rings after conducting a solution heat treatment to the expanded metal ring. In the manufacturing method, by executing the first circumference correction step and the second circumference correction step before and after the solution heat treatment, respectively, an expansion quantity for setting a circumference of each of the metal rings to become a predetermined length is attained.

Abstract: A method of producing a workpiece of a heat-resistant steel, such as hot forming tool steel, where the workpiece may be hardened and depassivated after mechanical machining and electrochemical treatment. The hardening including a reduction step, so that no depassivation need be performed by pickling, for example, before nitriding. The result of the hardening treatment is a favorable surface condition for stepwise nitriding.

Abstract: A process for producing a component of metal includes a) carrying out a heat treatment to harden the component, which ends with a heating process, especially with a tempering or microstructural transformation process, at a given temperature (TE); b) carrying out at least machining of the component at room temperature (TU) in order to provide its desired geometrical shape; and c) subsequent heating of the component to a temperature (T) which is greater than room temperature (TU).

Abstract: A steel to be air-hardened as part of heat treatments such as hardening-and-tempering, induction hardening, carburizing, carbonitriding or nitriding comprising, in weight %: C 0.10-0.55; Si 0.97-2.03; Mn 1.14-1.83; Cr 0.00-1.65; Mo 0.36-0.58; and the balance Fe + impurities.

Abstract: 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.

Abstract: A steel strip made of martensitic steel contains C+N at not more than 0.12 wt %, Si at not more than 1 wt %, Mn at not more than 7 wt %, Ni at 2 to 24 wt %, Cr at 2 to 16 wt %, Mo at not more than 2.5 wt %, and Ni-Bal value and Ms value defined by the following equations shown by weight percentage of each composition are respectively Ni-Bal≧1.2, Ms≧−28.

Abstract: Disclosed is a process for producing a retainer for a constant velocity joint for automobiles or the like, which has improved flexural strength properties without sacrificing the machinability, using a steel corresponding to SCr 415 (JIS) or SCM 415 (JIS). This production process comprises the steps of: providing a steel comprising by weight carbon (C): 0.10 to 0.25%, silicon (Si): 0.03 to 0.15%, manganese (Mn): 0.20 to 0.60%, sulfur (S): 0.003 to 0.030%, chromium (Cr): 1.00 to 1.50%, titanium (Ti): 0.05 to 0.20%, boron (B): 0.0005 to 0.0050%, and nitrogen (N): not more than 0.01% with the balance consisting of iron (Fe) and inevitable impurities; hot forging the steel at a heating temperature of 1000 to 1100° C. to prepare a forged product having a Rockwell hardness of not more than 88 HRB; machining and optionally piercing the forged product; carburizing and quenching and tempering the machined steel to attain an effective case depth of 0.4 to 0.

Abstract: A high-strength carburized part comprising a core having a chemical composition of C: 0.15 to 0.30% by weight, Si: 0.25 to 1.10% by weight, Mn: 0.3 to 1.20% by weight, Cr; 1.25 to 2.0% by weight and a balance including unavoidable impurities and Fe, a vacuum-carburized surface having a carbon ratio ranging from 1.0 to 1.5%, a region extending from the surface to a depth of 50 &mgr;m and having a grain boundary oxide layer with a depth of 1 &mgr;m or less, wherein a area ratio of carbides of said surface is from 5 to 15% and at least 90% of carbides have a grain size of 5 &mgr;m or less, wherein the core comprises an interior region which cannot be carburized.

Abstract: A method of improving wear-resistance and anti-seizing properties of slide surface of machineries, such as outer slide surfaces of piston pins of vehicle engines, wherein slide surfaces of iron or steel base materials of machineries are first processed carburizing, then the carburized surfaces are plated with chromium, and next the chromium-plated surfaces undergo impulses fine peening to produce lubricant-retaining cavities on the slide surfaces, which include fine cavities in the form of depressions in the chromium-plating layer and relatively large cavities produced by exfoliation of the chromium-plating layer.

Abstract: A method for producing a formed member made of a steel sheet according to the present invention is characterized by preparing a steel sheet material having tensile strength of 500 MPa or less and containing a nitriding element; forming a formed member having a predetermined shape by performing a plastic forming on the steel sheet material; and performing a nitriding treatment on the formed member so that an average hardness in the sheet thickness direction of the resultant steel sheet member is Hv 300 or more by Vickers hardness, and further characterized in that the difference in hardness between the surface part and the inside center part in the thickness direction of the steel sheet member of the formed member is Hv 200 or less by Vickers hardness, thereby it is possible to reliably obtain a formed member having a sufficiently high strength after a nitriding treatment while ensuring a plastic formability of a steel sheet in obtaining a formed member made of a steel sheet member of high strength by performi

Abstract: A piston ring having improved scuffing resistance, cracking resistance and fatigue resistance, consists of a high-chromium martensitic stainless steel and a sliding nitriding layer formed on the surface of said steel. The stainless steel consists of C: 0.3 to 1.0%; Cr: 14.0 to 21.0%, N: 0.05 to 0.50%, at least one of Mo, V, W and Nb: 0.03 to 3.0% in total, Si: 0.1 to 1.0%, Mn 0.1 to 1.0%, P: 0.05% or less, S: 0.05% or less, the balance being Fe and unavoidable impurities. The sliding nitriding layer comprises on its surface hard particles mainly consisting of nitrides in a range of from 0.2 to 2.0 &mgr;m of average particle size, 7 &mgr;m or less of the longest diameter, and from 5 to 30% in area ratio.

Abstract: Steel alloys susceptible to case and core hardening comprise 0.05 to 0.24 wt % carbon; 15 to 28 wt % cobalt and 1.5 to 9.5 wt % 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: A method for producing a steel material having a high fatigue strength and given a uniform residual stress by a rapid treatment. A marageing steel is subjected to a cold plastic working to have a predetermined dimension, to a solution treatment for 60 minutes or more at a temperature of 750 to 800° C., and to an aging.

Abstract: A steel wire of pearlite structure containing 0.8-1.0 mass % of C and 0.8-1.5 mass % of Si is disclosed. In the cross section of the steel wire the average hardness in a region up to 100 &mgr;m from the surface thereof is at least 50 higher that that in a deeper region based on micro-Vickers hardness. The steel wire is manufactured by working a wire rod having the abovementioned chemical composition through shaving, patenting and drawing processes, then strain-relief annealing the resultant wire, and thereafter subjecting the thus annealed wire to a short peening process. The steel wire can be produced through a drawing process without applying a quenching and tempering process, and are superior in heat resistance and fatigue strength.

Abstract: The continuous annealing furnace has two or more treatment chambers sequentially connected with each other and respectively filled with a gas atmosphere differing in carburizing property, which includes a carburizing chamber wherein roller members to be treated are carburized at 750° C. to 820° C., a slow cooling chamber wherein the roller members are cooled at said temperature or less of the carburizing chamber, an intermediate chamber including atmosphere gas blocking doors that can open/close an exit of the carburizing chamber and an entrance of the slow cooling chamber independently, and transferring means, and each chambers is filled to satisfy a relationship of K1−K2≧2 where K1 represents a partial pressure ratio between CO and CO2 in an atmosphere within the carburizing chamber and K2 represents a partial pressure ratio between CO and CO2 in an atmosphere within the slow cooling chamber.

Abstract: A stainless steel hydraulic component and method for making same hard turns a pre-heat treated stainless steel material, preferably a 400 series stainless steel material, provided in bar stock form in a single machining loading. Stainless steel hydraulic valve components made therefrom have shown improved leakage rate performance with the performance being fairly constant over a period of time for providing a longer functional life for the hydraulic valve component.

Abstract: A sintered sprocket is provided in which surface pressure resistance can be improved without using a forging processing. An Fe-based sintered alloy which contains C at 0.2 to 0.5% by weight, Mo at 0.2 to 1.0% by weight, and Ni at 0.2 to 1.0% by weight, and which exhibits a metallic structure in which an internal base layer comprises ferrite and bainite and in which the ferrite adjoins voids, is subjected to a rolling and is then subjected to carburizing and hardening.

Abstract: Disclosed is a process for producing an inner race for a constant velocity joint for automobiles or the like, which has improved rolling fatigue life and flexural strength properties without sacrificing cold forgeability and machinability, using SCM 420 (JIS) or a steel corresponding to SCM 420. This production process comprises the steps of: providing a steel comprising by weight carbon (C): 0.10 to 0.25%, silicon (Si): 0.03 to 0.15%, manganese (Mn): 0.20 to 0.60%, sulfur (S): 0.003 to 0.030%, chromium (Cr): 1.00 to 1.50%, titanium (Ti): 0.05 to 0.20%, boron (B): 0.0005 to 0.0050%, and nitrogen (N): not more than 0.

Abstract: Disclosed is a process for producing a retainer for a constant velocity joint for automobiles or the like, which has improved flexural strength properties without sacrificing the machinability, using a steel corresponding to SCr 415 (JIS) or SCM 415 (JIS). This production process comprises the steps of: providing a steel comprising by weight carbon (C): 0.10 to 0.25%, silicon (Si): 0.03 to 0.15%, manganese (Mn): 0.20 to 0.60%, sulfur (S): 0.003 to 0.030%, chromium (Cr): 1.00 to 1.50%, titanium (Ti): 0.05 to 0.20%, boron (B): 0.0005 to 0.0050%, and nitrogen (N): not more than 0.01% with the balance consisting of iron (Fe) and inevitable impurities; hot forging the steel at a heating temperature of 1000 to 1100° C. to prepare a forged product having a Rockwell hardness of not more than 88 HRB; machining and optionally piercing the forged product; carburizing and quenching and tempering the machined steel to attain an effective case depth of 0.4 to 0.

Abstract: The present invention is related to a method of manufacturing HLA for an internal combustion engine, wherein the friction of valve drain system can be reduced approximately 30% due to the polishing effect as well as the initial engine tune-up resulted from an etching treatment additionally applied on the upper surface of the HLA already treated with high carbon carburization.

Abstract: A laminated ring for use as a belt in transmitting power in a continuously variable transmission is produced by welding opposite ends of a sheet of maraging steel to produce a plurality of rings, and rolling said rings to a predetermined length. The rings are nitrided in a salt-bath nitriding process by dipping the rings in a molten salt containing 38-46% of CNO31 and 1-2% of CN− and heated to a temperature in the range from 480 to 530° C., for a period of time ranging from 10 to 25 minutes. The nitrided rings are finally stacked into a laminated ring.

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: 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: A surface treating and smoothing method of surface-treating and smoothing a sliding member including steps of finishing the sliding member by pressurized particle containing fluid blasting to a sliding surface with surface roughness ranging approximately 0.02 to 0.7 &mgr;mRa after pre-finishing it to a surface with surface roughness lower than lower one of a surface roughness of a counter member and 0.2 &mgr;mRa, treating the sliding member by salt-bath nitrocarburizing so as to provide the sliding member with surface hardness higher than surface hardness of the counter member but lower than 1500 Hv, and driving the sliding member and the counter member so as to slide on each other for running-in, thereby smoothing the surfaces of the sliding member and the counter member.

Abstract: A method for the production of hollow shafts from welded or seamlessly produced steel tubes having a maximum carbon content of 0.35% includes (1) carburizing a tube to a carbon content greater than 0.5%; (2) slowly cooling the carburized steel tube down from the process temperature, so that it undergoes no increase in hardness; (3) machining and/or non-cutting processing the carburized and soft steel tube to produce a workpiece blank; and (4) hardening the workpiece blank by local heating and quenching at desired points.

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 of treating a metallic machine part to increase wear life and to change surface appearance comprising the steps of roughening the surface, thereafter changing its color by case hardening and, subsequently, increasing the lubricity of the case hardened surface by coating the surface with a pigmented, solid perfluorinated lubricant of a color comparable to the color of the case hardened surface.

Abstract: A substantially carbon free (e.g. 50-80 ppm carbon max.) iron base melt is strip cast to provide a cast strip having a low strength, high ductility, essentially ferrite matrix substantially free of hardening acicular ferrite, bainite and martensite phases. The strip strength may be enhanced by subjecting the strip to a carburizing or nitriding treatment either directly after casting or after casting followed by cold rolling and annealing.

Abstract: A method and apparatus for making a piston ring in which a metal strip having a first coefficient of expansion is coiled about a special mandrel having a second greater coefficient of expansion and a threaded form that has a zero helix angle along most of its circumference or perimeter and then a relatively steep helix angle for a short distance.

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: In a manufacturing method of a valve spring, a coiled valve spring made of an oil-tempered wire is applied with nitriding treatment and is supported to be rotated about its center axis. During a shot peening process of the coiled valve spring, cut wires of Hv 650 to 850 in hardness and 1.0 to 0.6 mm in diameter are shot to the coiled valve spring at a first step, in a roller-type shot machine and cut wires of Hv 650 to 850 in hardness and 0.4 to 0.2 mm in diameter are shot to the coiled valve spring at a second step in a tumbling shot machine, the time for the second step being longer than the time for the first step.

Abstract: By controlling the thickness of the nitrization layer formed on the surface, the coil spring made of spring steel may be made highly resistant to permanent set and fatigue. By carbonitriding the material of the coil spring to a depth of 20 to 50 .mu.m from the surface thereof so as to have an internal hardness of Hv 540 or higher, the coil spring can be made to endure 10.sup.7 cycles of repeated high stress without suffering any significant permanent set.

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: 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: Method and apparatus for carburizing, quenching and tempering workpieces, by which the step of carburizing can be incorporated into a machining and manufacturing process to be performed by an on-line machining and manufacturing system as one stage thereof, and by which high-quality treatment or processing can be achieved without occurrences of variation in quality among heat-treated products. In this apparatus, a preheating chamber (2), six carburizing chambers (5a to 5f), a cooling chamber (6), a reheating chamber (7), a quenching chamber (8) are placed around an intermediate chamber (4) having a transport device (12). Further, a high-frequency induction heating technique is used for heating each of major ones of the treatment or processing chambers. Moreover, a plasma carburizing method is performed in the carburizing chambers.

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 decarburization-annealed steel strip as an intermediate material for grain-oriented electrical steel strip having good secondary recrystallization and excellent electrical properties is provided by causing a steel strip to possess a micro-structure in which the primary recrystallization grains have an average diameter d of not less than 15 .mu.m and a coefficient of diameter deviation .sigma.* of not more than 0.6.

Abstract: A method of producing a bevel gear is provided. The method comprises the steps of forging, from a case hardened and heated blank, a rough shaped bevel gear intermediate product having a toothed portion, outer burrs at a larger diameter end thereof and between adjacent teeth of the toothed portion, and a ring-shaped inner burr in a center hole thereof, setting the rough shaped bevel gear intermediate product in a trimming die during the time the rough shaped bevel gear intermediate product remains in an elevated temperature condition due to heat left therein after the step of forging, and trimming the outer burrs, and moving, after the step of trimming, the rough shaped bevel gear intermediate product from the trimming die to a sizing die in the vicinity of the trimming die and warm sizing the toothed portion in succession to the step of trimming.

Abstract: Improved corrosion, wear and fatigue resistance is provided for pieces formed of medium alloy, low carbon steel by subjecting the piece to a treatment process which includes a step of carburizing, followed by nitriding. The process is especially useful for producing durable and low-cost steel parts, for example for certain automotive and marine applications, pumps (especially positive displacement pumps), chemical or food processing equipment, power tools, and the like. The blade-carrying reciprocating shaft for a reciprocating power saw is a specific example.

Abstract: A method for forming a spring which can reduce variations in the surface hardness and the thickness of the hardened layer when the spring is nitrided. Before nitriding the spring, the thickness of an oxide film formed on the surface of the spring is reduced to 1.5 .mu.m or less by electropolishing or any other suitable means so that the residual stress of the spring will be -5 kgf/mm.sup.2 to 5 kgf/mm.sup.2 near its surface. With this arrangement, it is possible to increase the surface hardness and the thickness of the nitrided layer of the spring obtained by nitriding.

Abstract: A process for producing a coil spring comprises steps of: cold drawing a wire comprising: C in an amount of 0.55 to 0.75% by weight; Si in an amount of 1.00 to 2.50% by weight; at least two primary metals selected from the primary metal group consisting of: Mn in an amount of 0.30 to 1.5% by weight; Ni in an amount of 1.00 to 4.00% by weight; Cr in an amount of 0.50 to 2.50% by weight; Mo in an amount of 0.10 to 1.00% by weight; at least one secondary metal selected from the secondary metal group consisting of: V in an amount of 0.05 to 0.60% by weight; Nb in an amount of 0.05 to 0.60% by weight; and the balance of substantially Fe; oil quenching and tempering the wire; hot tempering the wire, thereby preparing the tempered wire whose tensile strength .sigma.b falls in the range of from 1370 to 1670 N/mm.sup.2 ; cold coiling; hardening and tempering; grinding; gas nitriding; high strength two-stage shot peening; and low temperature annealing the tempered wire.

Abstract: A brightening chemical polishing solution for a hardened steel article (e.g., a carburized and quenched gear) comprises hydrofluoric acid having a molar concentration of from 0.2 to 2 mol/l, hydrogen peroxide having a molar concentration of from 0.4 to 4 mol/l, and water, a molar ratio of the hydrofluoric acid to the hydrogen peroxide being from 1:1.5 to 1:2.8. The steel article is quench hardened and is chemically polished in the solution. A shot-peening is additionally performed, prior to the polishing.

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 case carburizable stainless steel alloy intended to be used at operating temperatures up to 700.degree. F. The alloy is able to achieve and maintain a high surface hardness when carburized and heat treated and combines high fracture toughness, hot hardness, metal-to-metal wear resistance and corrosion resistance while retaining core ductility and strength. The alloy consists essentially of (in weight percent) 0.1 to 0.25% carbon, 0 to 1% silicon, 0 to 1% manganese, 13 to 19% chromium, 1.75 to 5.25% nickel, 3 to 5% molybdenum, 0.25 to 1.25% vanadium, 5 to 14% cobalt, 0.01 to 0.1% niobium; 0 to 0.02% boron; and the balance iron and incidental impurities. The alloy is particularly suited for use in bearing applications and also in cams, shafts, gears, bolts and like articles exposed to elevated temperatures and corrosive atmospheres.

Abstract: In a process for producing a workpiece from sintered metal, especially from sintered iron, the latter is subjected, after sintering, to a steam treatment at temperatures below 500.degree. C., especially at 430.degree.-480.degree. C., at a steam partial pressure of from 20 to 80 mbar, especially from 30 to 50 mbar, to form an oxide layer on the surface, and to subsequent surface-hardening. Workpieces, especially internally geared wheels for starters, having a wear-resistant surface and, in the core, properties unchanged by the hardening are obtained.

Abstract: A high tensile steel sheet excelling in workability and stretch flanging formability, which is of a composite texture composed of a ferrite phase and a 2nd phase selected from the group consisting of martensite, bainite, pearlite, retained austenite and cold-transformed ferrite, wherein the volume fraction of the 2nd phase is hoe less than about 1.3 times higher at an outer region of the steel sheet than the volume fraction of the 2nd phase in a central region of the sheet thickness.