Method for producing resilient elements using method of anisotropic orientation of nanostructure in material

FIELD: mechanical engineering.

SUBSTANCE: high-speed heating of a rod up to a temperature above the Ac3 point of phase transformations, plastic deformation of the rod by screw compression with twisting in the direction of compression of the spring coil, instant hot coiling of the spring at a temperature above Ac3 with immediate coil quenching and tempering, ensuring anisotropically oriented steel structure is carried out.

EFFECT: improvement of quality of springs and reduction of energy consumption.

2 cl, 1 ex

 

The invention relates to mechanical engineering technology and can be used in the manufacture of springs of hardened steel.

The prior art method of making elastic elements(SU 1169999 A, IPC 4 C21D 9/02, 8/00)includes heating the workpiece to a temperature AU3the plastic deformation of the helical compression by tightening, hardening, wrapped in the direction of twisting of the workpiece.

There is a method allows the anisotropy of the properties of texture, oriented along the direction of the punitive actions of stress, which increases the values of the static and cyclic strength of the elastic elements. When the helical compression value de-carbonized layer decreases due to the greater degree of deformation on the surface (expansion layer). High-temperature thermomechanical treatment eliminates edits and polishing of the workpiece before it is wrapped and improves the properties of the cyclic strength and reliability against fracture.

The prior art method of manufacturing large springs (the Russian Federation No. 1234018, CL B21F 35/00, declared 13.08.84 published 30.05.86), selected as a prototype, including high-temperature thermomechanical processing of the workpiece transversely of the screw by pulling in the direction of deformation of a coil compression spring, high-speed heating of the material is key to a temperature above the point AU 3phase transformations winding spring, immediate hardening, tempering springs.

A known method can improve the operational reliability of the springs due to the fact that high-temperature machining of the workpiece creates a directional metal structure corresponding to deformation arising during operation of the spring under compression, and high velocity heating and hot wrapped with subsequent heat treatment creates additional padding.

The purpose of the invention is improving the quality of elastic elements, the reduction of energy consumption in the manufacture of elastic elements.

The technical result is achieved in that in the method of manufacturing elastic elements using the method of the anisotropic orientation of the nanostructure material including high-speed heating the workpiece to a temperature above the point AU3phase transformation, plastic deformation of the workpiece helical compression by twisting in the direction of the compression coil spring winding spring, immediate hardening, tempering, according to the invention the winding of the spring is made immediately after plastic deformation of the workpiece.

Given that from the point of high-speed heating to the point of hot winding billet is cooled by the mechanisms of plastic deformation and the environment, appropriate speed heat C the cooking implement to a temperature above the point AU 3not less than 50°C.

An example of carrying out the invention

Rod alloy steel continuously sequentially subjected to high-speed heating to a temperature of 50°C above the point Ac3phase transformations. Then the rod is subjected to plastic deformation of the helical compression by twisting in the direction of compression coil springs. Then carry out a wrapped hot springs at temperatures above point Ac3phase transformations with immediate powercobol quenching and subsequent tempering.

During vtmo is multidirectional deformation of the workpiece, includes compression with deformation rate of 15-20%, the shift of the metal in the transverse direction in the area of the conical section of the deformation of the helical compression with deformation rate of 10-12%, the curl in the cross section in the outlet area of the workpiece with the conical section of the deformation zone with a twisting strain 12-15% and the bending deformation when wrapped.

Improving the quality of the springs is due to the fact that during the deformation of the workpiece in different directions austenitic grain still in a hot condition is ground to a nanoscale level (200-500 nm), and hardening provides a phase change in the structure, i.e. the transition to the martensitic state, which allows to obtain a martensitic grain size of 100-300 nm.

This carbide composition is shining (cementite) is in the range of 10-60 nm and uniformly located in the martensitic structure.

In addition, when used as billets hot-rolled rod with the deformation of the helical compression removes scale, providing the roughness of the rod in the range of 2.5-10 μm with precision rod 9-10 kvalitet, which corresponds holodnokatannoj steel.

The reduction of energy consumption in the manufacture of elastic elements in comparison with the prototype is due to the fact that the manufacturing process of the elastic elements excluded re-heating of the workpiece after high-temperature thermomechanical processing to be wrapped.

1. A method of manufacturing spring steel with oriented anisotropic nanostructure, including high-speed heating the rod to a temperature above the point Ac3phase transformation, plastic deformation of the rod screw compression by twisting in the direction of the compression coil spring winding spring, hardening and tempering, wherein the exercise wrapped hot springs after plastic deformation at temperatures above Ac3with immediate powercobol quenching.

2. The method according to claim 1, characterized in that the high-speed heating of the workpiece is carried out to a temperature of not less than 50°C above the point AU3.



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: hot-rolled rod with diameter of 13-17 mm is made from steel containing the following, wt %: carbon 0.50-0.65, silicon 0.05-0.20, manganese 0.07-0.15, aluminium 0.02-0.09, nitrogen 0.004-0.016, titanium 0.025-0.10, niobium 0.010-0.035, chrome 0.05-0.10, nickel 0.05-0.10, copper 0.15-0.20, iron and inevitable impurities are the rest; a B-shaped terminal is made from the rod, heated up to 850-920°C, then cooled with a fast water flow during 6-8 seconds and annealing is performed at 180°C during 2 hours so that annealing martensite structures are provided in the surface layer of the terminal, and troostosorbite is provided in the core.

EFFECT: providing stability of mechanical properties of elastic terminals, relaxation stability and cyclic durability.

2 cl, 1 tbl, 1 ex

FIELD: process engineering.

SUBSTANCE: invention relates to machine building and may be used for producing compression springs. Proposed method comprises spring winding with pitch exceeding that of finished spring, stress relief, luminous capillary control, face grinding, shotcasting cold working and chamfering of coil ends. After shotcasting cold-working, spring plastic hardening is performed at 200…250°C by axial stress of (10…300)F3, where F3 is spring force at maximum strain.

EFFECT: higher operating properties.

2 cl

FIELD: machine building.

SUBSTANCE: method to strengthen cylindrical helical springs includes operations of winding, hardening and tempering, grit blasting and pre-stressing. At the final stage the internal surface of springs is cold worked. Cold working is done by means of core pulling or by impact action at the internal surface of the spring turn.

EFFECT: targeted action at an inner surface of spring turns by means of plastic deformation.

3 cl, 2 dwg

FIELD: machine building.

SUBSTANCE: spring terminal heated to austenitisation temperature is quickly cooled in jet flow of quenching fluid in the range of pearlitic and martnensitic transformation temperatures of 80-120°C. Depending upon article configuration and sizes, jet flow rate is SET to make 5-15 m/s, specific flow rate is adjusted in the range of 20-60 cm3/(cm2·s) to allow part cooling rate of 100-600°C/s while quenching fluid temperature is maintained equal to 30-60°C. Terminal quenching plant comprises high-pressure pump, filter and cooling chamber housing sprayer, slide and conveyor. Shutter is arranged at sprayer outlet and connected with drive to open and close it in time and vibrate it in closed position. Sprayer inner space follows that of spring terminal with minimum clearance while conveyor provides final cooling of spring terminals in stationary quenching fluid and discharging from cooling chamber.

EFFECT: higher quality and efficiency.

2 cl, 1 ex, 3 dwg

FIELD: transport.

SUBSTANCE: invention relates to automotive industry. Proposed method consists in producing bar from 8-30 mm-dia rod billets using steels other than manganese steel. Said bar is heated to 900-950°C for 20-35 min. Bar curves are shaped in special mandrels. Bar operating parameters are automatically controlled. Said bar is fed into hardening drum with hardening temperature of 830-870°C. Bar is hardened in water at 30-40°C, bar diameter making 8-25 mm. Bar is tempered into two-zone conveyor furnaces with interval between hardening and tempering not exceeding 4 hours at 480-520°C. It is cooled in water at not over 100°C or in air in closed room. Residual stress is removed by one-time angular turn of inclined section curves through 3-5° for 5-8 s. Elastic rubber sleeves are fitted. Shaped yokes are mounted asymmetrically on the surface of said sleeves with distance between centers making 688±1 mm. Said yokes are locked in sleeve elastic strain range at sleeve rubber mix pressure on bar surface making 0.5-11.5 MPa.

EFFECT: increased tolerable cyclic strain of car transverse stabilisers.

4 dwg

FIELD: metallurgy.

SUBSTANCE: spring is heated to temperature of quenching and is drawn in heated condition at pitch exceeding pitch of finished spring. Not cooled spring is heat treated. Cold spring is subjected to shot casting cold hardening, whereupon its coils are plastic hardened with axial load amounting to (10…300)F3, where F3 is force of spring at maximal deformation including deformation with preliminary usual spring hardening by ageing in compressed condition. Further, repeated load is applied increased proportionally to ratio of required camber to camber at application of primary load. Loads can be of vibration type. Spring setting is performed at higher requirements to power parameters.

EFFECT: upgraded quality and service life of springs at recovery of their flexible properties.

4 cl

FIELD: metallurgy.

SUBSTANCE: spring plate out of steel of reduced hardenability is heated and positioned in quenching die. A heated spring plate is clamped in die space and is simultaneously bent along radius and volume-surface quenched in quenching medium. Plates are bent and volume-surface quenched under pressure 2.5-3.0 kgf/cm2 of fast moving flow of quenching liquid during 10-20 sec and cooled to room temperature. Also, a spring plate is quenched along whole length from the middle to ends. The installation for implementation of this procedure consists of a die with a movable and stationary parts and of a system for supply of quenching liquid. Each part of the die has knives of specified radius; the central channel and cross slits are uniformly distributed on working surface from the middle of the plate. The slits are cut at angle to surface of a quenched spring plate and are communicated as well, as the central channel, with tanks of the system for supply of quenching liquid supplied through flexible sleeves and a pneumatic-hydraulic valve by means of a pump from a tank-reservoir.

EFFECT: high fatigue strength and wear resistance.

3 cl, 1 dwg

FIELD: process engineering.

SUBSTANCE: spring is, first, subjected to setting or annealing and, then, expanded with pitch exceeding that of finished spring. Heat treatment and shot-blast hardening are performed. Spring is pressed by axial load making (10÷300)F"з", where F"з" is spring force at maximum strain. Then, it is pressed by load increased proportional to relation between required setting to that caused by first loading. Note here that loads may be vibrational. Spring reached required height, no repeated pressing is required. In case there are increased requirements to spring force parametres, spring is trimmed again.

EFFECT: higher spring quality and complete recovery.

4 cl

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to recovery of elastic properties of springs. To increase performances of the spring to be recovers, it is hated and tempered, and expanded with pitch exceeding that of normal spring. Then, it is heat treated, shotblasted and pressed by axial lad of (10…300)F3, where F3 is spring force at minimum strain. Now, it is re-pressed at load proportional to relation between required compression and that resulted from application of the first load. Used loads may be caused by vibration. Preset spring height reached, no re-pressing can be performed. Given increased requirements to force parametres, spring can be straightened.

EFFECT: spring recovery method.

4 cl

FIELD: metallurgy.

SUBSTANCE: invention refers to ferrous metallurgy, particularly to fabricating spring steel. In a converter or electric furnace there is melted liquid steel containing the following elements, wt %: carbon 0.45 - 0.70, silicon 1.65 - 2.50, manganese 0.20-0.75, chromium 0.60 - 2, nickel 0.15 - 1, molybdenum (traces) - 1.0, vanadium 0.003 - 0.8, copper 0.10 - 1, titanium 0.020 - 0.2, niobium (traces) - 0.2, aluminium 0.002 - 0.050, phosphorus (traces) - 0.015, sulphur (traces) - 0.015, oxygen (traces) - 0.0020, nitrogen 0.0020 - 0.0110, iron and associated impurities at melting - the rest. Steel is cast and there are produced blooms, ingots or flat bars. During their solidification or after it they are cooled at rate 0.3°C/s within the range 1450 - 1300°C. The said blooms, ingots or flat bars are rolled at temperature 1200 - 800°C per one or two cycles of heating and rolling. Rods, rolled bars, work-pieces or springs made out of them are subject to austenisation within the range 850 - 1000°C and to successive quenching in water, polymer or oil and tempering at 300 - 550°C to strengthen steel to 55 HRC or more and to maximal dimension of nitrides or carbonitrides of titanium at depth 1.5 mm ± 0.5 mm from surface of rod, rolled bar, work-piece or spring with cross section of 100 mm2 area constituting 20 mcm or less. Also the said dimension is a value of square root of surface area of the said inclusions, shape of which is taken as square.

EFFECT: steel possesses upgraded tensile strength and durability, fatigue strength in air and in corrosion medium and high resistance to cyclic fatigue softening.

5 cl, 4 tbl, 4 dwg

FIELD: metallurgy.

SUBSTANCE: sheet is made of steel containing in wt %: 0.85-1.20 C, 0.05-2.00 Si, 0.05-0.50 Mn, 0.05-0.60 Cr, P ≤ 0.0150, Fe and unavoidable impurities making the rest. At least 97% of the head surface part located in area from head angular and top parts as initial point to depth of 10 mm features perlite structure. Perlite structure Vickers hardness makes HV 320-500. CMn/FMn ratio makes 1.0-5.0, where CMn [at %] is Mn concentration in cementite phase in perlite structure, FMn [at %] is Mn concentration in ferrite phase.

EFFECT: high wear resistance and impact strength.

3 cl, 13 dwg, 3 tbl, 1 ex

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EFFECT: higher hardness and resistance to stability loss.

FIELD: metallurgy.

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EFFECT: better mechanical properties and workability.

3 dwg, 3 tbl

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SUBSTANCE: workpiece from hypoeutectoid carbon or low-alloyed steel with sulphur content at upper level of grade constitution is subject to hot rolling with reduction ratio of (δ)≥70%, further cooling at inter-critical temperature interval (ITI), exposure at that temperature interval during the period of time, which provides refining of ferrite due to transition of impurities from α-solid solution to γ-solid solution, and further tempering. Composite with volume ratio of hardening martensitic phase ~ 20-25%, as well as with length of drawn sulphur inclusions (Fe, Mn) S 1≥80 mcm, and with directivity of martensite and ferrite layers, the misorientation of which does not exceed 15 angular degrees, is obtained.

EFFECT: higher characteristics of crack resistance.

1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: liquid alloy is quenched, its composition being as follows in wt %: boron - 2.1-3.5, silicon - 2.0-4.5, nickel - 5.0-10.0, cobalt - 15.0-30.0, chromium - 12.0-20.0, iron and unavoidable impurities making the rest, provided the following terms are satisfied: sum of boron and silicon makes 4.5-7.0, while that of boron and nickel equals 7.5-13.0. Then, intensive plastic deformation by twisting is performed by quasihydrostatic pressure and temperature and ultrasound processing at 18.0-22.0 kHz are performed.

EFFECT: high hardness and saturation magnetisation at low coercive force.

1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: rail from high-carbon pearlite steel, which has increased ductility, which contains the following components, wt %, is proposed: C: more than 0.85 to 1.40%, Si: 0.10%-2.00%, Mn: 0.10%-2.00%, Ti: 0.001%-0.01%, V: 0.005%-0.20%, N: less than 0.0040%, Fe and inevitable impurities are the rest. Contents of Ti and V meet the following formula: 5≤[V(wt %)]/[Ti(wt %)]≤20. Head part of the rail has pearlite structure. Method for obtaining pearlite rail involves hot rolling of bloom, finishing rolling of the hot rolling stage under conditions when temperature of finishing rolling FT, °C is established in the following range: Tc-25≤FT≤Tc+25. Tc=850+35×[C]+1,35×104x[Ti]+180×[V].

EFFECT: rails have increased ductility and wear resistance.

3 cl, 10 dwg, 5 tbl, 15 ex

FIELD: metallurgy.

SUBSTANCE: ingot manufacturing method involves tempering of an ingot, multiple forging with series change of orientation axis through 90° at the temperature interval of 773-923 K with total true deformation degree of not less than 3 and further annealing at the temperature above isothermic forging temperature by 50 K during 1-5 hours.

EFFECT: obtaining an austenitic steel ingot with nanocrystalline structure and improved strength properties.

2 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: proposed method comprises loading charge composed of the mix of steel and iron chips into alundum crucible, smelting in furnace at 1250-1300°C, holding at said temperature for 3-4 min, unloading from the furnace and tempering in water to produce a ledeburite form inhomogeneity composed of white pig iron. Then, obtained ingot is heated to 680-800°C, forged and tempered to obtain composite structure martensite-white pig iron.

EFFECT: simplified process, homogeneous properties.

1 tbl, 8 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: proposed method comprises built-up steel surface forming, cooling and tempering. Note here that said surface forming is conducted during cooling after building up at (Mm+80)°C to 60°C, where Mm is martensitic transformation temperature of built-up high-speed steel. Single tempering is performed at 520-540°C and cured for 20-40 min.

EFFECT: higher hardness.

1 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, preferably to the field of deformation-thermal processing of austenitic stainless steels. For production of nanocrystalline and submicrocrystalline structure of austenitic steel and increase of its strength properties at room temperature plastic deformation is carried out by means of hot rolling, which is carried out in the interval of temperatures of 973-1173 K to absolute deformation from 1 to 2 s with subsequent annealing in the interval of temperatures of 1323-1373 K and with time of delay within 10 - 30 minutes. Afterwards cold rolling is carried out to absolute deformation from more than 3.5 to 4 with subsequent annealing in the range of temperatures of 773-973 K with duration from 30 minutes to 2 hours.

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1 tbl, 2 dwg, 1 ex

FIELD: process engineering.

SUBSTANCE: invention relates to machine building and can be sued for making helical springs for rolling stock. Proposed method comprises hearing of the bar, coiling the spring at heating temperature, quenching of the spring, its tempering and upsetting, grinding of spring ends, blasting and controlling of spring parameters. Spring parameters and those of production process are set. Prior to coiling, heated bar is reduced to spring end shape approximating to that of spring nonworking coils to roll said bar axially. Quenching is carried out using mechanical effects applied to ambient medium while spring parameters are controlled continuously at every production step by comparison with preset magnitudes and process parameters and corrected by appropriate program. Cyclic fatigue is controlled at arbitrarily selected springs prior to grinding their ends and after blasting. Invention covers also the device to implement abode described method. Stable performances of springs in production and correction.

EFFECT: higher quality.

2 cl, 1 dwg

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