Method of producing sheets from aluminium alloys

FIELD: process engineering.

SUBSTANCE: invention is intended for making high-strength rolled sheet from aluminium alloys. Proposed method comprises making flat billet and lengthwise cold rolling to target thickness. Note here that cold rolling is performed at -80 to -196°C with total reduction of 35-99%. After rolling to thickness exceeding target thickness by 2.8-9.5 times, billet is turned through 90 degrees in rolling plane.

EFFECT: higher strength and toughness.

2 cl, 1 tbl

 

The invention relates to metallurgy, specifically to rolling production, and can be used to obtain high-strength rolled sheet of aluminum alloys.

A known method of manufacturing sheets and strip, of aluminium alloys, including the production of hot rolled billets, subsequent cold rolling to specified dimensions and final annealing [1].

The known method does not provide high strength and viscosity properties of leaves.

The closest analogue to the present invention is a method for the production of sheet and strip of aluminium alloys, including the production of hot rolled flat blanks, heat treatment and subsequent cold rolling in several passes [2].

The disadvantage of this method is that the sheets and tapes have low strength and frictional properties.

The technical problem solved by the invention is to improve strength and viscosity properties of leaves.

To solve the technical problem in the known method of producing sheets of aluminum alloys, including the production of flat blanks and subsequent longitudinal cold rolling to the final thickness, according to the invention, the cold rolling is carried out in a temperature range from -80 and up to -196°C with a total relative compression 35-99%. In addition, variance the implementation of the method after rolling the billet to the thickness greater than the final thickness of the sheet 2.8...9.5 times produce rotation in the plane of the rolling at a 90°angle.

The essence of the proposed invention consists in the following. Experiments have shown that the evolution of the grain structure of aluminum alloys during rolling total relative compression 35-99% at cryogenic temperatures in the range from -80 and up to -196°C is determined by the stretching and the dispersion of the grains down to the nano range, while the contribution of mechanical twinning is negligible. The main type of deformation is {111}<110> dislocation glide. On the basis of the formation of a large number of obstacles to the movement of the dislocation strength properties of the sheets increases. Simultaneously grinding grain structure promotes viscous properties.

However, if the longitudinal strain is carried out only in one direction, sheet acquires the anisotropy of mechanical properties: strength and frictional properties of samples cut along the rolling, higher than those for control samples. Anisotropy of mechanical properties constrains the use of high-strength sheet aluminum alloys.

To align the mechanical properties in the longitudinal and transverse directions after rolling the billet to the thickness pre is usausa final sheet thickness 2.8...9.5 times, produce a rotation in the plane of the rolling at a 90°angle. The rotation of the workpiece at an angle of 90° after reaching a thickness greater than the final thickness of the sheet 2.8...9.5 times, provides further plastic flow of metal in the transverse (compared to the initial direction. This reduces the elongation of the grains of the microstructure, reduces strokefest inclusions, allows to obtain a rolled sheet of aluminum alloys with isotropic mechanical properties.

It is found experimentally that when the temperature of the cold rolling above -80°C or total compression of less than 35% is not achieved, the dispersion microstructure down to nanosized grains. Rolled sheet has insufficient strength and plastic properties. When the temperature of the cold rolling below -196°C or total relative compression of more than 99% due to the reduction of resource technological plasticity is the embrittlement and fracture of rolled sheets of aluminum alloys in the rolls during rolling or in the process of further forming, which is unacceptable.

If the rotation of the workpiece at a 90° angle to produce when it is thicker than the end less than 2.8 times or more than 9.5 times its further rolling will not provide alignment of the microstructure and properties of the finished sheet in the longitudinal and transverse directions. In one case will be reobligate strength properties "across" the concluding passages, and the other "along".

Embodiments of the method

1. Hot rolled billet aluminum alloy with magnesium (3,5% Mg by weight) of thickness H=40 mm, width B=100 mm and length L=300 mm is dipped in liquid nitrogen and cooled to a temperature of t=-130°C.

The cooled billet narrow side set in rolls reversing mill quarto 800 and implement its longitudinal rolling for 8 passes with intermediate cooling in the thickness of 12 mm to the initial temperature of -130°C. the finish Rolling at a final sheet thickness h=8,0 mm Total relative compression ε is:

.

Laminated sheet is released at a temperature of 150°C, cut out designs along and across the direction of rolling and carry out tests of mechanical properties:

σinkg/mm2σtkg/mm2δ5, %KCU, kg·m/cm2
Along4029109
Across33257,87

2. All the e same operation as in example 1, except that after compression of the workpiece to an intermediate thickness hn=32 mm, which is greater than the final thickness of the sheet h in n=4 times:

produce rotation of the workpiece in the plane of the rolling at a 90°angle, and then continue its multi-pass rolling to the final thickness h=8.0 mm with intermediate cooling in the thickness of 12 mm to the initial temperature of -130°C.

Laminated sheet has the following mechanical properties:

σinkg/mm2σtkg/mm2δ5, %KCU, kg·m/cm2
along37259,08
across37259,08

Options for implementation of the proposed method and the indicators of efficiency listed in the table.

The modes of production of sheets of Fluminimaggiore alloy
№ p/p t, °Cε, %times90°rotationσinkg/mm2σtkg/mm2δ5, %KCU, kg·m/cm2
1-7034not DHL.no28/2224/208/57/4
2-8035not DHL.-:-39/3228/249/5,99/6
3-13080not DHL.-:-40/3329/2510/7,89/7
4-19699not DHL.-:- 41/3429/249/6,29/6
5-20099,5not DHL.-:-31/2226/228/6,17/3
6-70342,728/2321/246/87/5
7-80352,8-:-37/3725/259/98/8
8-130804,0-:-37/3725/259/98/8
9-196999,5 -:-37/3725/259/98/8
10-20099,510,0-:-31/2226/238/68/4
11+2075not DHL.no27/2223/198/56/3

From the data presented in the table, it follows that if implementation of the proposed method (options No. 2-4, No. 7-9) is the increase in strength and viscosity properties of sheets made of aluminum alloys. In addition, the rotation of the workpiece by 90° after reaching her thickness, 2.8...9.5 times greater than the final thickness of the sheet (options No. 7-9), increase the isotropy of mechanical properties.

In cases of transcendent values of the declared options (options # 1 and # 5, # 6 and # 9), and the implementation of the known method (option 11, [2]) is the decrease of the strength and viscosity properties of sheet metal, increases the anisotropy in predolin the m and transverse directions.

Technical appraisal and economic benefits of the proposed method consist in the fact that rolling at cryogenic temperatures between -80 and up to -196°C with a total relative compression 35-99% promotes intense crushing of the microstructure of aluminium alloys up to the nanostructure size throughout the thickness of the sheet, the exception of course of dynamic return and spontaneous loosening. This achieves the simultaneous increase in strength and viscosity properties. In addition, additional rotation of the workpiece thickness greater than the final thickness of the sheet 2.8...9.5 times, at a 90°angle, provides a reduction in the anisotropy of the mechanical properties of sheets of aluminum alloys with microcrystalline structure.

Due to the increase in strength and viscosity properties of sheets made from aluminium alloys, reduction of their thickness and weight by 10-15% while maintaining the overall strength of the product.

Literary sources

1. Ivao Osama "Aluminum foil and technology of its production." "Kinzoku. Kindoki." 1977, 47, No. 8, r.36-42.

2. USSR author's certificate No. 1548259, IPC C22F 1/04, 1988.

1. Method for the production of sheets of aluminum alloys, including the production of flat blanks and subsequent longitudinal cold rolling to the final thickness, wherein the cold rolling is carried out in a temperature the ohms between -80 and up to -196°C with a total relative compression 35-99%.

2. The method according to claim 1, characterized in that after rolling the billet to a thickness greater than the final thickness of the sheet 2.8...9.5 times, produce a rotation in the plane of the rolling at a 90°angle.



 

Same patents:

System of rolls // 2462323

FIELD: process engineering.

SUBSTANCE: rolls are arranged to de displaced axially by drives (4, 104, 204). Note here that the latter comprises, at least, one hydraulic cylinder (5, 6, 105, 106, 205) to control axial displacement of rolls. Proposed system comprises means (11, 12, 13, 14) to allow displacement of roll bearing holders (15, 16, 17, 18) perpendicular to axial direction A and in axial direction by rotary motion. Hydraulic cylinder is arranged in frame mounted spatially fixed or moving coupled with device elements.

EFFECT: simplified design.

2 cl, 3 dwg

FIELD: process engineering.

SUBSTANCE: proposed system serves to define parameters describing identity and/or in-service state of forming roll to be replaced and is provided with, at least, one sensor device fitted on said roll to memorise said parameters.Said device allows registration of parameters describing identity of forming roll being replaced. System incorporates also a reader to allow contactless reading of registered parameters from sensor device. Note here that said sensor device allows registration of data on forming roll state parameters and may be operated at forming roll temperature making at least 150°C. Besides, proposed system comprises cart for roll change. Note also that said sensor device will be arranged on replacement forming roll.

EFFECT: higher reliability.

14 cl, 5 dwg

FIELD: process engineering.

SUBSTANCE: proposed seal comprises cover and sealing V-like annular cuffs including case, jaw with working edges to get in contact with baffle and adapter fitted on bearing bush. Working edges are pressed against sealed surface by elastic properties of the jaws. Gaps resulting from wear of cuff working edges are ruled out by providing the proposed device with elastic ring elements with cross-section shaped to circle or ring fitted with interference between cuff case and jaw.

EFFECT: higher efficiency.

1 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. Rolling mill for rolling strip 4 has several main stands 1, 1' and reeler 2 arranged there behind. Said main stands incorporates working rolls 5, 5' and, at least, bearing rolls 6, 6'. Rolling mill control device 3 receives data on strip 4 to define, at least, one reduction A other than zero of strip 4 of all passes at rolling mill. Control device 3 uses entered data to define reduction of single pass for main stands 1, L. Said control device controls over stands 1, 1' and reeler 2 to make strip 4 be rolled in main stands in compliance with definite single-pass reductions and, then reeled, by reeler 2. Single-pass reduction of the main stand 1' arranged immediately ahead of reeler 2 equals zero while outlet side tension in strip 4 is smaller than that and inlet side. Strip 4 passes through said stand L with no deformation on, at least, one side.

EFFECT: higher quality of strip.

10 cl, 5 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. Rolling mill for rolling strip 4 has several main stands 1, 1' and reeler 2 arranged there behind. Said main stands incorporates working rolls 5, 5' and, at least, bearing rolls 6, 6'. Rolling mill control device 3 receives data on strip 4 to define, at least, one reduction A other than zero of strip 4 of all passes at rolling mill. Control device 3 uses entered data to define reduction of single pass for main stands 1, L. Said control device controls over stands 1, 1' and reeler 2 to make strip 4 be rolled in main stands in compliance with definite single-pass reductions and, then reeled, by reeler 2. Single-pass reduction of the main stand 1' arranged immediately ahead of reeler 2 equals zero while outlet side tension in strip 4 is smaller than that and inlet side. Strip 4 passes through said stand L with no deformation on, at least, one side.

EFFECT: higher quality of strip.

10 cl, 5 dwg

FIELD: metallurgy.

SUBSTANCE: method for obtaining high-strength wire from (α+β)-titanium-based martensite alloy involves obtaining of ingot, its hot deformation so that workpiece for drawing is obtained; drawing at room temperature till final size is obtained, and final heat treatment. After heat treatment is completed, the obtained workpieces are annealed in the air and machined; drawing is performed for many times with intermediate annealings in the air environment; at that, the machining is performed after the first drawing pass, and final heat treatment is performed in the air environment during 60-180 minutes at temperature of (0.5÷0.7)TSL °C with further cooling to room temperature.

EFFECT: increasing ultimate tensile strength at maintaining the high level of relative elongation due to uniformity of the structure throughout the length and section of wire.

1 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to rolling plant, and namely to tandem rolling plant for cold-rolled strip, with several roll stands located in one rolling mill; besides, in production direction (P) of metal strip the first roll stand is made as the drive roll stand and serves as an inlet for continuous roll stand section in which considerable reduction of metal strip thickness is performed, and due to the appropriate control of drive roll stand there can be achieved the increase in mechanical stress at metal strip inlet. There also described is control method of rolling plant, and namely tandem rolling plant for production of metal strip, in which the first roll stand is controlled in production direction (P) of metal strip as drive roll stand, in which by means of drive roll stand there performed is considerable increased in mechanical stress at metal strip inlet without considerable reduction of metal strip thickness.

EFFECT: providing the distribution of single reductions in compliance with design features of an individual roll stand in rolling mill.

17 cl, 2 dwg

Rolling device // 2459676

FIELD: process engineering.

SUBSTANCE: rolling device 1 is intended for axial displacement and flexure of work roll. Said device incorporates, at least, one upper and lower rolls 2, 3 fitted in common mill stand 7 and retained to make height-adjustable clearance in vertically displacing supports and supported by support rolls 4, 5. Besides, it comprises, at least, one device to displace axially one of rolls 2, 3 and one device to flex upper roll 3. Also, it comprises bending cylinder 16 with crossbars 12 acting on its ends and bending levers 13. Note here that roll 3 adjusting height of said clearance is guided by bending levers 13.

EFFECT: increased roll lift.

11 cl, 4 dwg

FIELD: process engineering.

SUBSTANCE: proposed method comprises rolling with support of, at least, partially manual control over rolling mil in rolling strips, or slabs, or rough stock. Higher accuracy in correction of mill parameters with due allowance for target parameters is ensured by defining, with respect to, at least, one definite point of mill, the portion of, at least, one metallurgical phase of metal influenced by phase state, and/or parameters of metal state, and portion of, at least, one phase with respect to, at least, one definite point of the mill is displayed to mill operator. Note here that path of said metal point and portion of, at least, one metal phase are continuously tracked up. Rolling mill comprises appropriate equipment.

EFFECT: higher quality of rolled stock.

18 cl, 4 dwg

FIELD: process engineering.

SUBSTANCE: proposed device comprises stand with bed struts 2, 12, 33. Note here that, at least, one rolling stand roll 3, 13 is arranged between bed struts as well as, at least, one roll adjustment device 5, 10, 50 arranged between roll 3, 13 and bed struts 2, 2a, 2b, 2c, 2d, 12, 33. Said adjustment device comprises actuator 25 with compressed working fluid. Said actuator is made up of hydraulic mechanism and sleeve assembly 25, 23. Note here that said sleeve assembly incorporates piston 34 displacing parallel with roll axis.

EFFECT: stable position of rolling device.

5 cl, 3 dwg

FIELD: plastic working of metals, possibly manufacture of thin high-strength foil of titanium.

SUBSTANCE: method comprises steps of multi-pass reversing cold rolling and vacuum annealing; repeating cycle; using as initial blank titanium blank with ultra-fine grain structure provided due to intensified plastic deformation by equal-duct angular pressing process; rolling at pitch 15 - 8% for achieving total deformation 70 - 86 % per one cycle; setting number N of cycles necessary for making foil with thickness h according to mathematical expression; realizing vacuum annealing, preferably at temperature 350 -360 C for 0.5 - 1 h. Invention provides possibilities for making titanium foil with thickness up to 10 micrometers.

EFFECT: enhanced strength characteristics of titanium foil of lowered thickness with the same technological platicity7777.

2 cl, 2 tbl

FIELD: rolling equipment, namely apparatuses for mounting rolls of working stands of rolling mills.

SUBSTANCE: apparatus includes screw-down cylinders connected with chocks of roll; liquid distributor communicated with pressure source and with screw-down cylinders; leverage mechanism joined with chocks of roll and with movable member of liquid distributor. The last is throttling one. Leverage mechanism includes rigid link, lever and doubled slide. First slide is mounted with possibility of horizontal motion relative to foundation of rolling mill; second slide is mounted with possibility of vertical motion relative to first slide. Rigid link is joined with chocks of roll and with second slide through articulation joint. First slide through lever is kinematically joined with movable member of liquid distributor. Rigid link is in the form of triangle. Leverage mechanism and screw-down cylinders are connected with chocks of upper or lower roll. First slide includes in addition controlled check valves of screw-down cylinders and system for controlling them. Invention provides possibility for redistributing pressure between screw-down cylinders in proportion to shift of leverage mechanism that is to automatically prevent skewing of roll.

EFFECT: automatic prevention of roll skewing, enhanced quality of rolled products, improved operational properties of roll.

6 cl, 2 dwg

FIELD: rolled stock production, namely equipment of shape bending mills, mainly for making tinned corrugated sheets.

SUBSTANCE: drive unit of shape bending mill with first guiding stand and pulling roller devices includes motor, reduction gear, sprockets, forcing and tensioning gear wheels, roller chain embracing sprockets along S-shaped curve and sine curve. Torque of motor is transmitted only to lower shaping rolls of even stands and of last stand of mill and also to both rolls of guiding stand and to horizontal rollers of pulling devices through sprockets mounted on their axles. Chain embraces sprockets of rolls of guiding stand and of rollers of pulling devices along S-shaped curve and it embraces sprockets of drive rolls and sprockets that are not joined with shaping rolls along sine curve. Axles of sprockets that are not joined with shaping rolls may be arranged higher than axles of lower drive rolls by value determined according to relation given in claims of invention.

EFFECT: lowered cost of shape bending mill, reduced power consumption for profiling, enhanced quality of ready shapes.

2 cl, 1 dwg, 1 ex

FIELD: automation of rolling processes.

SUBSTANCE: method comprises steps of measuring disturbance-stimulated strip thickness in front of rolling stand; controlling measurement result until inlet of stand; compensating it in stand by moving screws of screw-down mechanism at predetermined rate for preset time interval; measuring fluctuation of strip thickness relative to predetermined value when strip leaves stand; acting upon movement rate of screws according to disturbance and to fluctuation of strip thickness after multiplying said values and differentiating received product.

EFFECT: enhanced accuracy and reliability of controlling strip thickness.

2 dwg

FIELD: continuous rolling of strip, namely rolling strip having different thickness portions joined through transition wedge-shaped portion.

SUBSTANCE: method is used for rolling metallic strip 1 in rolling mill having at least two rolling stands. Metallic strip 1 has at least two zones 3,4 of different thickness mutually joined through wedge-shaped or approximately wedge-shaped transition portion 2. Rolling rate in rolling stand at rolling wedge-shaped portion 2 is tuned depending upon forward slip of rolling stand and also depending upon temperature of metallic strip 1. Apparatus for rolling includes rolling mill having at least two rolling stands providing tuning of rolling rate at rolling wedge -like or approximately wedge-like transition portion 2 of strip depending upon forward slip of rolling stand and upon temperature of metallic strip 1.

EFFECT: enhanced quality of rolled products.

2 cl, 5 dwg

FIELD: rolling equipment, namely transporting apparatuses, particularly roller table of rolling mill.

SUBSTANCE: roller table includes driven transporting rollers and lifting mechanism; lifting framework jointly mounted on struts and supporting transporting rollers; additional mechanism for lifting framework. Each mechanism for lifting framework is arranged in strut and it is in the form of sleeve, nut mounted inside said sleeve with possibility of motion and jointly connected through lug with framework; worm reduction gear joined with sleeve. In reduction gear and in sleeve there is opening in which screw is arranged. Said screw has cut splines in one end and in other end it has thread engaged with nut of sleeve. At least in one strut rotary crosspiece is jointly mounted. Lifting mechanism is mounted on said crosspiece.

EFFECT: enhanced operational efficiency of mill due to elimination of jamming movable links.

2 dwg

FIELD: automation of rolled stock production.

SUBSTANCE: at controlling thickness of tube wall in multi-stand continuous stretch-reducing mill, thickness of tube wall is measured behind mill by means of wall thickness measuring devices. Measured values are processed in computing unit. Revolution numbers of drive engines of rolls are controlled by means of units for controlling revolution number. In order to minimize formation of inner multi-arc profile at passing tube, total elongation value is kept constant due to changing revolution number of drive engines of rolls under control of computing unit.

EFFECT: enhanced quality of products.

5 cl, 4 dwg

FIELD: making of embossing on the commercial packing materials.

SUBSTANCE: the offered technology is dealt with making embossment on the flat materials and is used for packing of tobacco products. Rollers of the devices for making embossment, which are used for machining of the flat materials, including the firs driven roller and the conjugate roller are located in parallel to each other in a holder and may be placed so, that to enter into a definite mutual contact. At least one of the rollers for making embossment is located in a replaceable unit. At that the replaceable unit is supplied with retention tools. The holder contains pockets, the form of which is in essence complimentary for the retention tools so, that the replaceable unit may be entered in a predominantly defined position into the holder by insertion of the retention tools into corresponding pockets. The given technology provides more mild replacement of the rollers.

EFFECT: the invention ensures more mild replacement of the rollers.

20 cl, 16 dwg

FIELD: rolled stock production, namely apparatuses for mounting -dismounting bearing unit of backup roll of rolling stand.

SUBSTANCE: apparatus includes chock in which bearing assembly for roll journal is arranged. Apparatus that may be temporarily joined with bearing unit and may be axially moved in direction of backup roll and from it includes lever type inner and outer cams. Inner cams are introduced to end part of backup roll journal; outer cams are introduced to bearing unit. Inner and outer cams are mounted with possibility of rotation and locking by means of bayonet type lock in end part of journal and in bearing unit. End part of journal and intermediate ring screwed-on to bearing unit at its outer side are in the form of clover leaf having through grooves for inner and outer cams. Said cams after their rotation to clamp position may engage with respective locking protrusions of journal end part and of intermediate ring. In front of outer cams, pressure ring arranged before bearing assembly of journal is mounted.

EFFECT: lowered costs of changing bearing assemblies, increased useful life period and enlarged using range of apparatus.

5 cl, 3 dwg

FIELD: metallurgy, processes for making hot rolled band of magnesium alloy.

SUBSTANCE: method comprises steps of producing strip blank by continuous casting of melt of magnesium alloy; hot rolling of strip blank directly after casting at several passes for producing hot rolled band with thickness no more than 50 mm. Hot rolling is performed at initial temperature values 250°C - 500°C for providing final thickness of band no more than 4 mm. At first pass of hot rolling reduction degree is equal at least to 15%.

EFFECT: possibility for making magnesium sheets with improved deformation capability at less costs of manufacturing process.

11 cl, 1 dwg, 2 tbl, 1 ex

Up!