Abstract: A valve spring includes a nitrided layer, and a core portion that is further inward than the nitrided layer. A chemical composition of the core portion consists of, in mass %, C: 0.53 to 0.59%, Si: 2.51 to 2.90%, Mn: 0.70 to 0.85%, P: 0.020% or less, S: 0.020% or less, Cr: 1.40 to 1.70%, Mo: 0.17 to 0.53%, V: 0.23 to 0.33%, Ca: 0.0001 to 0.0050%, Cu: 0.050% or less, Ni: 0.050% or less, Al: 0.0050% or less, Ti: 0.050% or less, and N: 0.0070% or less, with the balance being Fe and impurities. In the core portion, a number density of V-based precipitates having a maximum diameter ranging from 2 to 10 nm is 500 to 8000 per ?m2, and in the core portion, a numerical proportion of Ca sulfides with respect to a total number of oxide-based inclusions and sulfide-based inclusions is 0.20% or less.

Abstract: An Inconel 625 alloy with high aluminum content and a preparation method thereof are provided. The alloy includes following components by mass percentage: chromium 5˜13%, ferrum 5%, niobium 4.15%, molybdenum 10%, aluminum 5˜9% and a rest is nickel. The preparation method includes: step (1): weighing reactive materials according to a preset ratio and putting the reactive materials into a planetary ball miller for ball milling; step (2): pressing the ball milled reactive materials into a cake-shaped slab; step (3) putting the cake-shaped slab into a reactor and putting an igniter on the cake-shaped slab, then adding the reactor with protective gas, heating up until a self-propagating reaction occurs in the reactor, thereby obtaining a base alloy; step (4): performing secondary smelting on the base alloy to obtain an ingot; step (5): performing a solution treatment on the ingot to obtain the Inconel 625 alloy with high aluminum content.

Abstract: Provided are a Ni-based heat resistant superalloy for aircraft engine cases excellent in high-temperature characteristic such as tensile characteristics and low-cycle fatigue characteristics in a high-temperature range and also excellent in workability, and an aircraft engine case formed of the same. The Ni-based heat resistant superalloy has composition containing, by mass, Co: 4.0 to 11.0%, Cr: 12.0 to 17.0%, Al: 2.0 to 4.0%, Ti: 2.0 to 4.0%, Al+Ti: 4.6 to 6.7%, Mo: more than 5.5 to 10.0%, W: more than 0 to 4.0%, B: 0.001 to 0.040%, C: 0.02 to 0.06%, Zr: 0 to 0.05%, Mg: 0 to 0.005%, P: 0 to 0.01%, Nb: 0 to 1.0%, Ta: 0 to 1.0%, and Fe: 0 to 2.0%, and the balance of Ni with inevitable impurities, and is suitable for aircraft engine cases.

Abstract: An ultrahigh-strength spring steel, used as steel for a vehicle engine valve spring may include 0.5 to 0.7 wt % of C, 1.3 to 2.5 wt % of Si, 0.6 to 1.2 wt % of Mn, 0.6 to 1.5 wt % of Cr, 0.01 to 0.5 wt % of Mo, 0.01 to 0.9 wt % of Ni, 0.5 wt % or less (excluding 0 wt %) of V, 0.5 wt % or less (excluding 0 wt %) of Nb, 0.3 wt % or less (excluding 0 wt %) of Ti, 1.0 wt % or less (excluding 0 wt %) of Co, 0.1 wt % or less (excluding 0 wt %) of B, 0.3 wt % or less (excluding 0 wt %) of W, 0.3 wt % or less (excluding 0 wt %) of Cu, 0.3 wt % or less (excluding 0 wt %) of Al, 0.03 wt % or less (excluding 0 wt %) of N, 0.003 wt % or less (excluding 0 wt %) of O, and a remainder of Iron (Fe) and inevitable impurities.

Abstract: A device for composing a series of satays, comprising a series of separate holders (8), wherein each holder is provided with a series of recesses, a horizontal frame (4) and a vertical frame (5), wherein the horizontal frame is suitable for horizontally moving the holders up to the vertical frame, wherein the vertical frame is suitable for separately moving each holder vertically upwards, wherein the holders are kept in a horizontal position. The present invention also relates to a method for composing a series of satays.

Abstract: A steel for spring includes C: 0.5 to 0.6%, Si: 1.0 to 1.8%, Mn: 0.1 to 1.0%, Cr: 0.1 to 1.0%, P: 0.035% or less, S: 0.035% or less, by mass %, and a balance of iron and inevitable impurities, as the overall composition, wherein an area ratio of an internal structure on an optional cross section comprises bainite: 65% or more, retained austenite: 6 to 13%, and a balance of martensite, and average C content in the retained austenite is 0.65 to 1.7%. The steel for spring can have high strength in which tensile strength is 1800 MPa or more and have high ductility.

Abstract: Disclosed is steel for a leaf spring with high fatigue strength containing, in mass percentage, C: 0.40 to 0.54%, Si: 0.40 to 0.90%, Mn: 0.40 to 1.20%, Cr: 0.70 to 1.50%, Ti: 0.070 to 0.150%, B: 0.0005 to 0.0050%, N: 0.0100% or less, and a remainder composed of Fe and impurity elements. Also disclosed is a high fatigue-strength leaf spring part obtained by forming the steel. The steel for a leaf spring is prepared to have a Ti content and a N content to satisfy a relation of Ti/N?10. Preferably, the leaf spring part is subjected to a shot peening treatment in a temperature range of the room temperature through 400° C. with a bending stress of 650 to 1900 MPa being applied to it.

Abstract: High strength steel wire for spring containing, by mass %, C: 0.67% to less than 0.75%, Si: 2.0 to 2.5%, Mn: 0.5 to 1.2%, Cr: 0.8 to 1.3%, V: 0.03 to 0.20%, Mo: 0.05 to 0.25%, W: 0.05 to 0.30%, and N: 0.003 to 0.007%, having a total of contents of Mn and V of 0.70%?Mn+V?1.27% and a total of contents of Mo and W of 0.13%?Mo+W?0.35%, limiting P: 0.025% or less, S: 0.025% or less, and Al: 0.003% or less, and having a balance of iron and unavoidable impurities, having a microstructure comprised of, by volume percent, over 6% to 15% of retained austenite and tempered martensite, having a prior-austenite grain size number of 10 or more, having a density of presence of spheroidal carbides with a circle equivalent diameter of 0.2 to 0.5 ?m of 0.06 particles/?m2 or less, having a density of presence of spheroidal carbides with a circle equivalent diameter of over 0.5 ?m of 0.01 particles/?m2 or less, and having a tensile strength of 2100 to 2350 MPa.

Abstract: Provided is a steel wire rod for a high strength and high toughness spring having excellent cold workability, the steel wire rod having a composition comprising: in weight %, C: 0.4 to 0.7%, Si: 1.5 to 3.5%, Mn: 0.3 to 1.0%, Cr: 0.01 to 1.5%, Ni: 0.01 to 1.0%, Cu: 0.01 to 1.0%, B: 0.005 to 0.02%, Al: 0.1% or less, O: 0.0020% or less, P: 0.02% or less, S: 0.02% or less, N: 0.02% or less, remainder Fe, and other unavoidable impurities, having a microstructure formed of ferrite and pearlite, and in which a prior (before cooling) austenite grain size is 8 ?m or less.

Abstract: A steel wire rod is obtained, in which a gas flow rate during gas stirring in molten steel treatment is controlled to be 0.0005 Nm3/min to 0.004 Nm3/min per molten steel of 1 ton, thereby the rod satisfies a specified composition, and oxide base inclusions in any section including an axis line of the steel wire rod satisfy the following composition X, the inclusions having width of 2 ?m or more perpendicular to a rolling direction, wherein the number of the oxide base inclusions of the following composition A is 1 to 20, and the number of the oxide base inclusions of the following composition B is less than 1: composition X: when composition of inclusions is converted to Al2O3+MgO+CaO+SiO2+MnO=100%, Al2O3+CaO+SiO2?70% is given. composition A: when composition of inclusions is converted to Al2O3+CaO+SiO2=100%, 20%?CaO?50% and Al2O3?30% are given; and composition B: when composition of inclusions is converted to Al2O3+CaO+SiO2=100%, CaO>50% is given.

Abstract: Disclosed is high strength spring steel that can limit the depth of pitting occurring when corroded and therefore possesses high strength as well as excellent pitting corrosion resistance and corrosion fatigue property, with a composition containing: C: greater than 0.35 mass % and less than 0.50 mass %; Si: greater than L75 mass % and less than or equal to 3.00 mass %; Mn: 0.2 mass % to 1.0 mass %; Cr: 0.01 mass % to 0.04 mass %; P: 0.025 mass % or less; S: 0.025 mass % or less; Mo: 0.1 mass % to 1.0 mass %; and 0: 0.0015 mass % or less, under a condition that a PC value calculated by PC=4.2×([C]+[Mn])+0.1×(1/[Si]+1/[Mo])+20.3×[Cr]+0.001×(1/[N]) is greater than 3.3 and equal to or less than 8.0. Also disclosed is a preferred method for manufacturing the same.

Abstract: A spring wire with a hardness of 50 to 56 HRC is subjected to first and second shot peening processes within a warm working temperature range of 150° C. to 350° C. In the first shot peening process, a first shot of a shot size of at least 1.0 mm is used. In the second shot peening process, a second shot smaller in shot size than the first shot is used. Through these shot peening processes, compressive residual stress is imparted to the spring wire. The spring wire includes a residual stress increase part, residual stress peak part, and residual stress decrease part. In the residual stress decrease part, a part including a compressive residual stress magnitude equivalent to the magnitude of the compressive residual stress at a surface of the spring wire exists at a region at a depth exceeding the permissible pit depth.

Abstract: An object of this invention is to provide a steel for high-cleanliness spring which is useful for the production of a spring excellent in fatigue characteristics in high Si steels. The steel for high-cleanliness spring with excellent fatigue characteristics according to the invention contains: in terms of mass %, C: 1.2% or less (excluding 0%); Si: 1.8% to 4%; Mn: 0.1% to 2.0%; and total Al: 0.01% or less (excluding 0%), with the remainder being iron and inevitable impurities, in which the Si amount and a solute (SIMS) Ca amount in the steel satisfy a relationship of the following expression (1): Si×10?7?solute (SIMS) Ca?Si×5×10?7??(1) (in which each of the solute (SIMS) Ca and Si represents the amount thereof (mass %) in the steel).

Abstract: In a high-tensile steel plate according to the invention, the carbon equivalent Pcm represented in Expression (1) is from 0.180% to 0.220%, the surface hardness is a Vicker's hardness of 285 or less, the ratio of a Martensite Austenite constituent in the surface layer is not more than 10%, the ratio of a mixed structure of ferrite and bainite inside beyond the surface layer is not less than 90%, the ratio of the bainite in the mixed structure is not less than 10%, the thickness of the lath of bainite is not more than 1 ?m, the length of the lath is not more than 20 ?m, and the segregation ratio as the ratio of the Mn concentration in the center segregation part relative to the Mn concentration at a part in a depth equal to ¼ of the thickness of the plate from the surface is not more than 1.3. Pcm=C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5B . . . (1) where the element symbols in Expression (1) represent the % by mass of the respective elements.

Abstract: A steel wire for a cold-formed spring according to the present invention contains a prescribed chemical component composition, wherein: a martensitic transformation start temperature MS1 shown by the following expression (1) is in the range from 280° C. to 380° C.; the austenite grain size number N of austenite grains is No. 12 or more; the grain boundary share of carbide precipitated along the austenite grain boundaries is 50% or less; the amount of retained austenite after austenitized and tempered is 20 vol. % or less; and the tensile strength is 2,000 MPa or more; MS1=550?361[C]?39[Mn]?20[Cr]??(1), where [C], [Mn] and [Cr] represent the contents (mass %) of C, Mn and Cr, respectively. Such a steel wire can: secure hot-rolling formability and subsequent drawability while aiming at higher strength and higher stress; moreover exhibit excellent corrosion resistance; and obtain a spring (mainly a suspension spring for an automobile) excellent also in fatigue strength which is a basic required characteristic.

Abstract: A spring steel having a high strength of 1900 MPa or more and superior in the brittle fracture resistance, as well as a method for manufacturing the same, are provided. The high strength spring steel comprises, as basic components in mass %, C: 0.4-0.6%, Si: 1.4-3.0%, Mn: 0.1-1.0%, Cr: 0.2-2.5%, P: 0.025% or less, S: 0.025% or less, N: 0.006% or less, Al: 0.1% or less, and O: 0.003% or less, the amount of solute C being 0.15% or less, the amount of Cr contained as a Cr-containing precipitate being 0.10% or less, and a TS value represented by the following equation being 24.8% or more, and in point of structure, the pre-austenite grain diameter being 10 ?m or smaller, wherein TS=28.5*[C]+4.9*[Si]+0.5*[Mn]+2.5*[Cr]+1.7*[V]+3.7*[Mo] where [X] stands for mass % of element X.

Abstract: An improved method for salvaging a spring element with a degraded force constant for return to a work environment. The spring element is subjected to a high temperature and extended duration annealing treatment alone or in combination with other treatments. The resultant salvaged spring is characterized by a more durable force constant relative to the original spring when it was new.

Abstract: Spring element, in particular spring rail for wipers, in particular of motor vehicles, with a low tendency to vibrate or a high attenuation, made from a ferritic chromium steel comprising 0.03 to 0.12% of carbon, 0.2 to 0.9% of silicon, 0.3 to 1% of manganese, 13 to 20% of chromium, 0.1 to 2.0% of molybdenum, 0.05 to 1.0% of copper, 0.02 to 0.05% of nitrogen, less than 0.01% of titanium, 0.01 to 0.10% of niobium and 0.02 to 0.25% of vanadium, remainder iron.

Abstract: Disclosed herein is a spring wire rod excelling in fatigue characteristics. It contains TiN inclusions having a specific size defined by the ratio of each group in all the visual fields as follows: (1) Visual fields in which the maximum thickness is no larger than 5 ?m: less than 5% (2) Visual fields in which the maximum thickness is larger than 5 ?m and no larger than 10 ?m: no more than 30% (3) Visual fields in which the maximum thickness is larger than 10 ?m and no larger than 25 ?m: no less than 70% (4) Visual fields in which the maximum thickness is larger than 25 ?m: less than 5% The visual field is the cross section passing through the center line of the wire rod.

Abstract: A high-strength steel excellent in hydrogen embrittlement resistance is provided. The high-strength steel of the present invention excellent in hydrogen embrittlement resistance has a tensile strength of 1800 N/mm2 or above, contains 0.3 to 0.7% (percent by mass) C, 0.95 to 5.0% Cr, not higher than 0.6% and higher than 0% Mn, and 0.7 to 2.5% Si, and contains at least one of Mg, Ca, Sr, Ba, Li, Na and K so as to meet the following conditions: (1) the upper limits of the Mg, the Ca, the Sr, the Ba, the Li, the Na and the K content are 0.05%, and (2) the Mg, the Ca, the Sr, the Ba, the Li, the Na and the K content meet Expression (1): Cr + Mn 4 ? 1000 × [ Ca + Mg + Sr + Ba 2 + Li + Na + K 8 ] .

Abstract: The present invention provides a spring steel having both a high strength and a good coiling property after heat treatment, characterized by: containing, in mass, C: 0.4 to 1.2%, Si: 0.9 to 3.0%, Mn: 0.1 to 2.0%, P: 0.015% or less, S: 0.015% or less, Cr: 2.5% or less, and N: 0.001 to 0.015%, with the balance consisting of Fe and unavoidable impurities; and, in the microstructure of the steel after hot rolling, the density of globular cementite carbides 0.2 to 3 ?m in circle-equivalent diameter being 0.5 piece/?m2 or less and the density of globular cementite carbides over 3 ?m in circle-equivalent diameter being 0.005 piece/?m2 or less.

Abstract: Disclosed is a hard-drawn spring which exhibits fatigue strength and sag resistance equal or superior to springs produced using an oil-tempered wire. The hard-drawn spring is produced using a steel wire containing 0.5 to 0.7 mass % of C, 1.0 to 1.95 mass % of Si, 0.5 to 1.5 mass % of Mn and 0.5 to 1.5 mass % of Cr, with the balance being Fe and inevitable impurities. In the steel wire, the number of carbides having circle-equivalent diameters of 0.1 ?m or more is 5 particles/100 ?m2 or less.

Abstract: The present invention intends to provide a method for manufacturing a high-strength spring, which is capable of generating a higher level of compressive residual stress than that given by conventional methods. This object is achieved as follows: After the final heating process, such as the tempering (in the case of a heat-treated spring) or removing-strain annealing (in the case of a cold-formed spring), a shot peening process is performed on the spring while the surface temperature of the spring is within the range from 265 to 340° C. (preferably from 300 to 340° C.). Subsequently, the spring is rapidly cooled. Preferably, a prestressing process is performed before the shot peening process, or after the shot peening process and before the rapid cooling process. The rapid cooling process may be either a water-cooling process or an oil-cooling process. A forced-air cooling process may be used if the wire diameter of the spring is small.

Abstract: A steel for high-strength springs contains, on the mass basis, 0.35% to 0.65% of C, 1.4% to 2.5% of Si, 0.1% to 1.0% of Mn, 2.0% or less (exclusive of 0%) of Cr, 1.0% or less (exclusive of 0%) of Ni, 1.0% or less (exclusive of 0%) of Cu, 0.020% or less (exclusive of 0%) of P, 0.020% or less (exclusive of 0%) of S, 0.006% or less (exclusive of 0%) of N:, and 0.1% or less (exclusive of 0%) of Al, with the remainder being iron and inevitable impurities, in which Wp(Fe) and W(C) satisfy the following condition: Wp(Fe)>5×W(C), wherein Wp(Fe) is the content of Fe (percent by mass) constituting Fe-containing precipitates in the steel; and W(C) is the carbon content (percent by mass) of the steel. The steel is excellent in cold workability and quality stability.

Abstract: A method of surface-treating a reactor member for effectively removing a Cr-deficient layer and a work-hardened layer considered to be a cause of stress corrosion cracking (SCC) under low-stress conditions. The method of surface-treating a reactor member which is worked by bending (step 1) and then processed by a heat treatment (step 2), in which a work-hardened layer is formed by the bending, and in which a Cr-deficient layer is formed due to an oxide film attached by the heat treatment, uses at least one of: acid wash; grinding; electrolytic polishing; electro-discharge machining; surface cutting; surface deoxidation and softening; wet blasting; laser machining; or surface plating (step 3) to remove the work-hardened layer and the Cr-deficient layer from the reactor member or to prevent contact of the work-hardened layer and the Cr-deficient layer of the reactor member with a primary coolant.

Abstract: The present invention provides a high strength steel used for spring steel that has excellent hydrogen embrittlement resistance. The high strength steel which spring steel having excellent hydrogen embrittlement resistance comprises 0.20 to 0.60% of C, 1.0 to 3.0% of Si, 1.0 to 3.5% of Mn, higher than 0% and not higher than 1.5% of Al, 0.15% or less P, 0.02% or less S, and balance of iron and inevitable impurities and the structure includes: 1% or more residual austenite; 80% or more in total of bainitic ferrite and martensite; and 10% or less (may be 0%) in total content of ferrite and pearlite in the proportion of area to the entire structure, and also the mean axis ratio (major axis/minor axis) of the residual austenite grains is 5 or higher and the steel tensile strength is 1860 MPa or higher.

Abstract: Disclosed herein is an ultra clean spring steel which contains inclusions easily elongated and broken into fine particles by hot rolling and which is easily adaptive to cold rolling and yields springs excelling in fatigue characteristics. The spring steel is characterized in that the wire contains oxide inclusions with a sulfur concentration no more than 10 mass % such that no less than 70% (in terms of numbers) of such inclusions, which exist in the outer layer outside one quarter of the diameter of the wire and have a width no smaller than 3 ?m, satisfies the formula (1) below, CaO+Al2O3+SiO2+MnO+MgO>80 (mass %) .

Abstract: The invention relates to a rolling bearing which provides superior noiselessness and high corrosion resistance and longer life, and is manufactured at a low cost, a material for the rolling bearing, and an instrument including a rotating portion using the rolling bearing. A plurality of rolling elements are provided between an inner ring and an outer ring. At least one of the inner and outer rings and is formed of corrosion resistant bearing steel comprising a specific chemical component. The corrosion resistant bearing steel comprises eutectic carbides having an average value of circle equivalent diameter of 0.2 to 1.6 ?m, an average area of 0.03 to 2 ?m2, and an area ratio of 2 to 7%. The hardness of the corrision resistant bearing steel is HRC 58 to 62 by JIS. The amount of retained austenite in the corrosion resistant bearing steel is 6 volume % or less.

Abstract: Leaf springs have improved durability in spite of using inexpensive spring steel such as SUP9 and SUP11 as materials. While a spring main body, made of the spring steel in which Brinell hardness is under 555 HBW and not less than 388 HBW (corresponding to a diameter of under 2.70 mm of hardness and not less than 3.10mm of hardness on a Brinell ball mark), is maintained at 150 to 400° C., the load is applied in the direction in which the spring main body is to be used, and the first shotpeening is performed at the plane where the tensile stress acts.

Abstract: A process for thermomechanical treatment of steel for torsionally-strained spring elements, the initial material being heated with a heating rate of at least 50 K/s and austenitized, and then, being formed in at least one forming step with the formed product being quenched to below the martensite temperature to martensite and then tempered. To improve the strength or toughness properties of the spring steel in the strain direction of the torsionally strained spring elements so that the increase of vibration strength is considerable, the initial material is heated to a temperature above the recrystallization temperature and then formed at such a temperature, that dynamic and/or static recrystallization of the austenite occurs, and that the recrystallized austenite of the formed product is quenched.

Abstract: This invention relates to a stainless steel gasket having markedly improved strength and fatigue properties due to precipitation strengthening. Its composition comprises C: at most 0.03%, Si: at most 1.0%, Mn: at most 2%, Cr: 16.0%-18.0%, Ni: 6.0%-8.0%, N: at most 0.25%, if necessary Nb: at most 0.30%, and a remainder of Fe and unavoidable impurities. After cold rolling, final annealing is carried out, and after a structure is formed of recrystallized grains with an average grain diameter of at most 5 ?m having an area ratio of 50-100% and an unrecrystallized portion having an area ratio of 0-50%, a metal gasket is formed by steps including temper rolling with a reduction of at least 30% to make the area ratio of a strain induced martensite phase at least 40%, and forming and heat treatment at 200-350° C.

Abstract: The present invention is directed to a method for producing a helical spring which comprises the steps of providing a plurality of parameters for defining a desired configuration of a target helical spring, setting at least bending positions and twisting positions on the basis of the plurality of parameters, and bending and twisting the element wire at the positions set in response to every predetermined feeding amount of the element wire, to produce the target helical spring. The parameters includes number of coils, coil diameter and lead of the target helical spring. At least the bending positions may be adjusted in response to the cycle of alternating diameters between a local maximum diameter and a local minimum diameter of the target helical spring.

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: In a production process for highly strengthened springs, the process comprises performing a first shot peening to a spring steel having a hardness of a diameter of 2.7 mm or less on a Brinell ball mark while applying stress to the springs at a warm temperature in the range of 150 to 350° C.

Abstract: An Ni-based or Ni—Co-based heat-resistant alloy wire excellent in resistance to sag at high temperatures ranging from 600 to 700° C., which excellent resistance is most suitable for spring materials. The heat-resistant alloy wire contains (a) 0.01 to 0.40 wt % C, 5.0 to 25.0 wt % Cr, and 0.2 to 8.0 wt % Al; (b) at least one constituent selected from the group consisting of 1.0 to 18.0 wt % Mo, 0.5 to 15.0 wt % W, 0.5 to 5.0 wt % Nb, 1,0 to 10.0 wt % Ta, 0.1 to 5.0 wt % Ti and 0.001 to 0.05 wt % B; (c) at least one constituent selected from the group consisting of 3.0 to 20.0 wt % Fe and 1.0 to 30.0 wt % Co; and (d) the remaining constituent consisting mainly of Ni and unavoidable impurities. The wire has (a) a tensile strength not less than 1,400 N/mm2 and less than 1,800 N/mm2, (b) an average crystal-grain diameter not less than 5 &mgr;m and less than 50 &mgr;m in a cross section, and (c) a crystal-grain aspect ratio (a major-axis/minor-axis ratio) of 1.2 to 10 in a longitudinal section.

Abstract: A fixture and process for assembly of semiconductor modules. Each module comprises a substrate and a cover attached to the substrate. The fixture comprises a baseplate adapted to accept the substrate and a spring-loading device containing a shape memory alloy spring engaging the cover. The shape memory alloy spring exerts a lesser force at room temperature and an elevated force at the bonding temperature of the bonding agent used to attach the cover to the substrate.

Abstract: The present invention provides a spring steel showing a sufficient reduction in area and an impact toughness while the steel has a high strength, in particular a tensile strength as high as at least 1,500 Mpa. A high toughness spring steel according to the present invention comprises, based on mass, 0.45 to 0.85% of C, 0.9 to 2.5% of Si, 0.1 to 1.2% of Mn, 0.1 to 2.0% of Cr, 0.005 to 0.07% of Ti, 0.001 to 0.007% of N, the Ti content being greater than four times the N content in terms of percent by mass, 0.0005 to 0.0060% B, at least one of 0.0005 to 0.01% Mg, 0.0005 to 0.01% La, and 0.0005 to 0.01% Ce, P and S with restrictive contents of less than 0.020% and less than 0.020%, respectively, and the balance of Fe and unavoidable impurities, and selectively contains V, Nb, Ni, Mo and Cu. The percent area of oxides and sulfides is not more than 0.1%.

Abstract: A method of making a spring are described. The spring is made by etching or cutting at least one spiral arm in a flat substrate leaving residual material around the arm. The intermediate residual material is either pushed or lifted to form a conical spring.

Abstract: A method for manufacturing a coiled spring having a high fatigue strength to be used for example as a suspension spring of a car using a rod of tensile strength 1910 to 2020 N/mm2 and diameter 8 to 17 mm. In a cold coiling step, the rod is formed into a coil. Annealing is then carried out to remove strains having arisen inside the coil during the coiling step. A hot setting step of utilizing surplus heat from the annealing step and applying a predetermined load to the coil to compress it for a predetermined time is then carried out. After that, multi-stage shot peening is carried out on the coil.

Abstract: This invention provides an oil-tempered wire having high strength (tensile strength of not less than 1960 MPa) and excellent workability and specifically provides a steel wire for high-strength springs comprising as steel components, in weight percent, C   0.4-0.7% Si   1.2-2.5% Mn   0.1-0.5% Cr   0.4-2.0% Al 0.0001-0.005%, and being limited to P not more than 0.015% and S not more than 0.015%, the balance being Fe and unavoidable impurities, the steel wire having no nonmetallic inclusions of a size greater than 15 &mgr;m, a tensile strength of not less than 1960 MPa, and a yield ratio (&sgr;0.2/&sgr;B) of not less than 0.8 and not greater than 0.9 or a yield ratio (&sgr;0.2/&sgr;B) of not less than 0.8 and an amount of residual austenite of not greater than 6%. This invention also provides a method of producing the steel wire.

Abstract: A spring steel containing SiO2, Al2O3, CaO, and MgO as oxide type inclusions, which have an average composition (by weight) of 35%≦SiO2≦75%, 5%≦Al2O3≦30%, 10%≦CaO≦50%, and MgO≦5% (excluding 0%). This spring steel is superior in fatigue properties.

Abstract: An improved bearing steel, adapted for the manufacturing of thick-walled bearing rings, containing, in weight-%: C 1.00-1.10 Si 0.15 max Mn 1.35-1.65 Cr 1.70-1.90 Ni 1.00-1.15 Mo 0.40-0.50 Cu 0.30 max. Al 0.015-0.050 the balance being Fe and normal residual elements and contaminants.

Abstract: Steel springs are cold coiled, then hardened by electrical resistance heating, and then quenched. The invention may be used to produce hardened springs with uniform mechanical and physical characteristics, fine grain microstructures, and high fatigue resistance. The heat hardening process may be individually controlled for each spring, and it may be performed in a very short period of time. The process time may be so short as to preclude decarburization, making it unnecessary to use a controlled endothermic atmosphere. The free lengths of the finished springs may be controlled by applying axial forces during heat hardening. According to one aspect of the invention, the coiled central section of the spring is made harder than its ends. The equipment for practicing the invention may have a compact, uncomplicated construction.

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: A non-heat treated wire or bar steel for springs which is characterized by having in its as-rolled state a tensile strength of 120-150 kgf/mm2 and a bending breakage rate no higher than 15% when tested according to JIS Z-2248 under the condition of r/d=2.8 where r (mm) denotes the inside radius of the bending curvature and d (mm) denotes the diameter of the as-rolled stock.

Abstract: The invention relates to a method for making arcuate coil springs from straight coil springs and particularly includes a phase of bending the straight springs during a heat treatment, which method provides exceptional results in that for the bending, a lasting arcuate shape is imparted to the springs substantially by giving the springs the shape of a portion of a turn to provide the spring with a counter-defect prior to the subsequent finishing steps. The invention also relates to a spring manufactured according to such a method and to devices for carrying out the method which include devices for holding at least the end coils of the springs in staggered positions, which devices may include a holder provided with fastening devices.

Abstract: Stainless steel wire of diameter smaller than 2 mm and with a tensile strength greater than 2100 MPa, consisting of a steel whose chemical composition includes, by weight: 0%.ltoreq.C.ltoreq.0.03%, 0%.ltoreq.Mn.ltoreq.2%, 0%.ltoreq.Si.ltoreq.0.5%, 8%.ltoreq.Ni.ltoreq.9%, 17%.ltoreq.Cr.ltoreq.18%, 0%.ltoreq.Mo.ltoreq.0.4%, 3%.ltoreq.Cu.ltoreq.3.5%, 0%.ltoreq.N.ltoreq.0.03%, S.ltoreq.0.01%, P.ltoreq.0.04%, the remainder being iron and impurities resulting from the production. Process of manufacture of the wire and uses.

Abstract: A high-strength oil-tempered steel wire with excellent spring fabrication property that is made of spring low-alloy steel, having a decarburized layer of reduced hardness extending to a depth of not greater than 200 .mu.m from the wire surface, a wire surface hardness in the range from an Hv (Vickers hardness) of 420 to an Hv of 50 below the Hv of the wire interior, and an Hv at the interior of the wire beyond the depth of the decarburized layer of not less than 550. The spring low-alloy steel can preferably comprise, in weight percent, 0.45-0.80% C, 1.2-2.5% Si, 0.5-1.5% Mn, 0.5-2.0% Cr and the balance of Fe and unavoidable impurities.

Abstract: A method of manufacturing helical springs from steel wire. The springs' skin is thermomechanically hardened by shot peening the unstressed springs followed by thermally destressing them, and shot peening them again. The second shot peening is carried out in at least two steps. The method produces springs that are just as strong as conventional but smaller and lighter in weight. The first one of the steps is a rough shot peening with shot that is coarser than in the second one of the steps which is a fine shot peening was shot at a lower speed than in the first step. This increases compression of the wire's surface and polishes the wire's surface.

Abstract: A coil spring made of an oil-tempered steel wire with internal hardness of more than Hv 550 in cross-section, the surface hardness of the oil-tempered steel wire being determined in an extent between Hv 420 in a minimum value and hardness defined by subtraction of Hv 50 from the internal hardness in a maximum value.