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 difference in average hardness between a region up to 100 ?m from the surface thereof and a deeper region is within 50 in 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 to a shot peening process. The steel wire has a high heat resistance and a high fatigue strength, and can be produced through a drawing process without applying a quenching and tempering process.

Abstract: Disclosed is a cold formable spring steel wire excellent in cold cutting capability and fatigue properties, in which the steel wire satisfies given composition, has an average globular carbide particle size [?(ab)]:1.0 ?m or less with aspect ratio (a/b, a: major axis of carbide, b: minor axis of carbide) being 2 or less, a ratio (area %) of the globular carbide in the steel: (0.1 to 3)×amount (mass %) of C in the steel, an amount (mass %) of Cr in the globular carbide: [0.4×amount (mass %) of Cr in the steel] or less, hardenability factor (Dic): between 110 mm and 450 mm, and tensile stress of 2000 MPa or more.

Abstract: A magnet assembly connectable to a metal assembly in an engaging fashion, a metal assembly connectable with the magnet assembly in an engaging fashion and a snapping mechanism comprising the magnet assembly and the metal assembly are disclosed, to be used with a strap and a watch case. A leaf spring element and a base element to be used with a watch case are also disclosed, together with manufacturing processes and a system and method to teach the concept of time.

Abstract: Disclosed is a steel wire rod for hard-drawn springs capable of exhibiting fatigue strength and sag resistance equivalent to or higher than springs made of an oil-tempered wire. The steel wire rod contains carbon in a range from 0.5 to less than 0.7 mass %, silicon in a range from 1.4 to 2.5 mass %, manganese in a range from 0.5 to 1.5 mass %, chromium in a range from 0.05 to 2.0 mass %, and vanadium in a range from 0.05 to 0.40 mass %, and has an area ratio Rp with respect to pearlite which satisfies the mathematical expression (1): Rp(area %)?55×[C]+61??(1) where [C] denotes the content (mass %) of carbon.

Abstract: Various apparatus and methods for an actuator and display using one or more shape memory springs. A shape memory spring is heated and urges a pin to a first or extended position. The pin may be supported in the first position by a supporting mechanism. The shape memory spring is heated electically, and in some embodiments under the control of a processor. The present invention may be used to display information provided in a user interface from a computer program, including text, numerical data, and graphical images.

Abstract: A manufacturing method for a composite coil spring includes the following steps: preparing a mold, winding a coil former around a mandrel of the mold, winding composite material pre-preg, compressing and heating, opening the mold and detaching the mandrel and the coiled coil former.

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: Furnace cart assembly for loading high temperature vacuum furnaces for treating target material, for example, metal parts, under extreme temperature and vacuum environments. The furnace cart includes electrical heating elements as an integral part of the cart, which elements are adapted for releasable connection to the furnace electrical supply. When so connected the furnace cart heating elements can form a part of the heating system of the furnace. The lower part of the furnace cart assembly, including a frame above and supported on wheels, the frame having heat reflection means on at least Its upper surfaces providing some protection from heat is preferably also protected from heat during furnace operation by insulating material above the frame (the material desirably supported by the frame but separated therefrom).

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 provides a cold-formed spring having high fatigue strength and high corrosion fatigue strength, a specific type of steel for such a spring, and a method of manufacturing such a cold-formed coil spring. The spring according to the present invention is made from a steel material containing, in weight percentage, 0.45 to 0.52% of C, 1.80 to 2.00% of Si, 0.30 to 0.80% of Ni, 0.15 to 0.35% of Cr and 0.15 to 0.30% of V, with Fe substantially constituting the remaining percentage. A wire is produced from the steel, and the wire is subjected to a high-frequency heating process, whereby the wire is hardened at a temperature of 920 to 1040° C. for 5 to 10 seconds, and then tempered at a temperature of 450 to 550° C. for 5 to 20 seconds so that its hardness becomes 50.5 to 53.5 HRC. Finally, the wire undergoes a shot peening process so that its residual stress at 0.2 mm depth from the surface becomes −600 MPa or higher.

Abstract: The invention relates to a high-strength, age-hardenable, corrosion-resistant maraging type spring steel, which is essentially comprised of 6.0 to 9.0 wt. % of Ni, 11.0 to 15.0 wt. % of Cr, 0.1 to 0.3 wt. % of Ti, 0.2 to 0.3 wt. % of Be and of a remainder consisting of Fe, whose martensite temperature Ms≧130° C. and which has a ferrite content cferrite of less than 3%.

Abstract: The present invention is directed to method for setting a formed helical compression spring. At the out set, parameters are measured to determine a reaction force axis of a formed helical compression spring. Next, A target reaction force axis of the spring is compared with the reaction force axis determined by the measured parameters to provide an error between the target reaction force axis and the detected reaction force axis. Then, a tilt angle of at least one of the compression plates tilted to an end plane of the spring is provided, in at least one direction on a plane including a coil axis of the spring, on the basis of the error between the target reaction force axis and the detected reaction force axis. Then, at least one of the compression plates is actuated to pressurize the spring, with at least one of the compression plates tilted to the end plane of the spring by the tilt angle.

Abstract: A high-strength steel wire for heat-resistant springs has both excellent high-temperature tensile strength and excellent high-temperature sag resistance at a temperature as high as 350 to 500° C., particularly at 400° C. or so (these properties are needed for spring materials). The steel wire contains (a) 0.01 to 0.08 wt % C, 0.18 to 0.25 wt % N, 0.5 to 4.0 wt % Mn, 16 to 20 wt % Cr, and 8.0 to 10.5 wt % Ni, (b) at least one constituent selected from the group consisting of 0.1 to 3.0 wt % Mo, 0.1 to 2.0 wt % Nb, 0.1 to 2.0 wt % Ti and 0.3 to 2.0 wt % Si, and (c) mainly Fe and unavoidable impurities both of which constitute the remainder. The steel wire has (a) a tensile strength of at least 1,300 N/mm2 and less than 2,000 N/mm2 before being treated with low-temperature annealing, and (b) a maximum crystal-grain diameter of less than 12 &mgr;m in the &ggr; phase (austenite) in a transverse cross section of the wire.

Abstract: [OBJECT] An oil-tempered wire for a cold-formed coil spring having a quality equivalent of or higher than a hot-formed coil spring is provided. A cold-formed coil spring made from the oil-tempered wire is also provided.

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: 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 difference in average hardness between a region up to 100 &mgr;m from the surface thereof and a deeper region is within 50 in 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 to a shot peening process. The steel wire has a high heat resistance and a high fatigue strength, and can be produced through a drawing process without applying a quenching and tempering process.

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: Through electro slag refining of a bloom of a stainless, precipitation hardenable stainless steel of 17-7 PH type, the fatigue resistance of springs made of cold drawn wires of said material is increased substantially. This depends on the fact that large slag inclusions, which can initiate fatigue failures, are eliminated at the ESR remelting, while longer zones containing concentrations of small slag inclusions are substantially reduced. The material is particularly suitable for springs in injection pumps for Diesel engines.

Abstract: A spring steel which is superior in both shaving properties and green drawing properties, which are important in spring production. A process for making the spring steel into wire rods for good springs. A rolled spring steel superior in workability characterized in that it has the following mechanical properties. Tensile strength≦1200 MPa 30%≦reduction of area≦70% A process for producing a steel wire rod for springs from said spring steel, said process comprising drawing, shaving, and oil tempering, which are carried out sequentially, said drawing being optionally followed by prescribed treatment.

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: 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: A spring is provided having a high durability in actual use and sagging resistance of the same level as or higher than conventional ones through improvement of the corrosion fatigue resistance. The spring uses as a material a steel including C: 0.35-0.55%, Si: 1.60-3.00%, Mn: 0.20-1.50%, S: 0.010% or less, Ni: 0.40-3.00%, Cr: 0.10-1.50%, N: 0.010-0.025%, V: 0.05-0.50% and Fe balance. The steel is heat treated to have a hardness of 50.5-55.0 HCC and shot-peened at a moderate temperature to render a residual stress of −600 MPa or more at a depth of 0.2 mm below the surface. The temperature at which the spring is shot-peened is preferably 100-300° C., and the hardness of shot particles for the shot-peening is preferably 450-600 Hv.

Abstract: A spiral parts heat treatment apparatus includes a first guide, a transfer unit, a second guide, and a controller. The first guide has a carrier portion that continuously conveys the manufactured spiral parts carried thereon in a longitudinal direction. The transfer unit is disposed downstream from the first guide to feed the spiral parts one by one after discrimination. The second guide is provided continuously to the transfer unit and has a carrier portion and a driving portion. The carrier portion serves to guide the spiral parts carried thereon in the longitudinal direction in the heat treatment furnace. The driving portion serves to push the spiral parts from a rear end side thereof and a driving portion. The controller performs a control operation so as to feed the spiral parts one by one.

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.

Abstract: Disclosed herein is apparatus for fabricating a coil spring including axially opposite end convolutions having respective ends respectively knotted to the associated end convolutions, which apparatus comprises a frame, a coil forming device mounted on the frame and operative to initially form a coil spring including axially opposite end convolutions having respective free ends, a tempering device mounted on the frame and operative to temper the initially formed coil spring, a knotting mechanism mounted on the frame and operative to respectively knot the free ends of the tempered coil spring to the associated end convolutions, and a transport mechanism mounted on the frame and operative to transport the initially formed coil spring to the tempering device, and to transport the tempered coil spring to the knotting mechanism.

Abstract: The present invention provides, at low cost, a valve spring steel having a tensile strength as high as 210 to 240 kgf/mm.sup.2 after oil tempering. The high strength spring steel comprises, based on weight, 0.65 to 0.85% of C, 1.90 to 2.40% of Si, 0.50 to 1.00% of Mn, 0.70 to 1.30% of Cr, 0.10 to 0.30% of Mo, 0.20 to 0.50% of V, 0.01 to 0.04% of Nb and the balance Fe and unavoidable impurities and is subjected to heating at temperature of 1,050 to 1,250.degree. C. and then to rolling so that carbides in the steel have a size of up to 0.15 .mu.m in terms of equivalent circle. A valve spring having a tensile strength as high as 210 to 240 kgf/mm.sup.2 after oil tempering and stabilized quality can be produced while the material cost is greatly reduced by decreasing costly alloying components as much as possible.

Abstract: A Belleville spring comprising a thin strip of hardened spring steel coiled into a circular shaped body with a frusto-conical configuration having an inner diameter and an outer diameter, wherein the strip has two free ends and the coiled spring steel body has the free ends joined together.

Abstract: The subject invention provides a method for manufacturing a spring band clip, wherein an alloyed steel is shaped, annealed, levelled into a narrow band, then shaped by stamping and bending into a non-machined clip, and the surface of the non-machined clip is smoothed and treated to produce resistance to corrosion; wherein the steel comprises iron as the main component and one or more of the following components by weight: 0.32 to 0.55% C; up to 2.0% Si; up to 2.0% Mn; up to 0.04% P; up to 0.04% S; 17.5 to 20% Cr; up to 1% Ni; 0.5 to 2.5% Mo; up to 0.5% V; up to 0.1% Al; up to 0.1% Co; up to 0.4% Cu; up to 0.4% Pb; up to 0.1% Se; up to 0.1% Te; up to 0.005% Ti; up to 0.1% W; up to 0.05% Zr; up to 0.01% O.sub.2 ; up to 0.01% N; up to 0.1% Bi; up to 0.001% B; up to 0.05% Nb; wherein the non-machined clip is austenitized prior to being smoothed and is converted into martensite by heat treatment in a salt-, oil-, or water bath, or by quenching at about the austenitizing temperature.

Abstract: Belleville spring pressure plate of increased height for use in a high performance clutch assembly exerts a greater force than the original height plate, is usable without modification of the original clutch and is longer lasting in service after being thermally conditioned to a martensitic state to lose the memory of its original, lower height and stress tempered before being set in a new, increased height shape.

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 low decarburization high toughness spring steel for an automobile suspending spring, and a manufacturing process therefor, are disclosed. In this steel, the effect of the sag resistance promoting element (Si) is maximized without reducing the carbon content, so that the problems of the decarburization and the lowering of the toughness (caused by the addition of silicon) should be solved during the manufacturing of the spring steel. The spring steel of the present invention is composed of in weight %: 0.5-0.7% of C, 1.0-3.5% of Si, 0.3-1.5% of Mn, 0.3-1.0% of Cr, 0.05-0.5% of V and/or Nb, less than 0.02% of P, less than 0.02% of S, 0.5-5.0% of Ni, and other indispensable impurities, the balance being Fe.

Abstract: A method of optimizing the distribution of inherent stress in springs intended for vehicle suspensions, especially in the rod cross-section of high-strength helical compression springs, whereby the springs are set and bombarded with balls. The springs are forwarded for the operations setting and bombardment at a gradient of strength prescribed for the particular rod cross-section.

Abstract: A clutch diaphragm comprises a peripheral Belleville ring portion and a central portion having a central aperture and comprising a set of radial fingers separated by slots, each of which extends from a blind end which is close to the peripheral portion to an inner end which is open into the central aperture, the latter being common to all of the slots.In a method of making this diaphragm, a flat blank is heat treated and is then soaked and hot formed to give the diaphragm a first diaphragm angle. It is then tempered in a tempering oven. The diaphragm is then transferred from the tempering oven to a stabilizing press, in which the conicity of the diaphragm is reversed while it is still hot from the tempering oven, so that instead of the first angle it now has an inversion angle.

Abstract: A high-strength spring steel has a high fatigue limit and is characterized by restricting the number of oxide particle inclusion having a diameter of not less than 10 .mu.m in steel to not more than 12 particles/100 mm.sup.2.

Abstract: A hot rolled steel bar is subjected to controlled hot roll finishing and cooling conditions which, together with the composition of the steel and controlled subsequent heat treating and quenching conditions, enable the formation of a steel spring having both relatively high hardness and high toughness.

Abstract: Process for the manufacture of components from untreated steel, comprising a series of heat treatment and forming operations, characterised by heating the steel to a temperature above the transition point (austenizing), isothermal quenching in a fluidized bed bath immediately after the austenizing heating giving the steel a bainitic structure and then forming the components under mild conditions.

Abstract: Disclosed herein is a new method for continuous heat treatment to be applied to the production of oil tempered steel wires for springs having high strength and high toughness to meet the requirement for weight reduction.The heat treatments are applicable to a medium carbon low alloy spring steel which does not undergo martensitic transformation substantially upon oil hardening alone. It comprises performing two-step accelerated hardening consistin of oil hardening and immediately following water hardening and subsequently performing tempering. The medium carbon low alloy steel is one which consists 0.40-0.65% carbon and Si and Mn as essential components and further at least one species of Cr, Ni, Mo, and V, and have the chemical composition corresponding to and Mf point lower than 80.degree. C. (preferably 10.degree.-70.degree. C.). It is desirable that the oil be wiped from the steel wire after the oil hardening and before the water hardening.

Abstract: The high-temperature relaxation resistance of spring steel is improved by providing a specified composition of the steel, and subjecting that steel composition to a controlled heat treatment. The high-temperature relaxation resistance, which can not be estimated from the mechanical properties (e.g. strength and hardness) of steel materials at an ordinary temperature, is improved by these conditions which the inventors have found out from many experiments. Especially, the temper-softening resistance is enhanced by an increase of the Si content. The density of dislocation is lowered by providing fine carbides (MO.sub.2 C) serving as inhibitors for the migration of dislocation. These are precipitated by a controlled heat treatment without reducing hardness in the tempered state. Consequently, the obtained spring steel can be used operated in a high-temperature environment for a long time without a deterioration in its properties.

Abstract: A vehicle suspension member such as leaf spring (50) is provided having at least one plate (3) having an irradiation exposed region (R) therein that is generally parallel to a longitudinal axis ("L/A") extending between opposite ends of plate (3) and operative to provide a metallurgical discontinuity extending therealong between opposite ends thereof that is effective to divert crack propagation in a direction generally parallel to axis ("L/A").

Abstract: A spring steel containing 0.35 to 0.50% of carbon is refined to the hardness of .phi. 2.50 to 2.70 mm in Brinell indentation diameter (HBD) by rapid cooling for quenching and tempering. This spring steel is subjected to warm shot peening at a temperature of 150.degree. to 300.degree. C. (423 to 573 K.) by using long-lived practical shots with the normal hardness of .phi. 2.65 to 2.80 mm in HBD, whereupon a high-strength spring is obtained having a compressive residual stress in its surface and enjoying the maximum shearing stress of 110 to 135 kgf/mm.sup.2 (1080 to 1325 MPa).