Thin sheet manufacturing method
SUBSTANCE: manufacturing method of thin sheets from pseudo-alpha titanium alloys involves deformation of an ingot into a slab, mechanical processing of a slab, multipass rolling of a slab for a semi-finished rolled stock, cutting of the semi-finished rolled stock into sheet workpieces, their assembly into a pack and its rolling and finishing operations. Multipass slab rolling is performed at several stages. After the semi-finished rolled stock is cut into sheet workpieces, their finishing operations are performed. Assembly of sheet workpieces into a pack is performed by laying so that direction of sheets of the previous rolling is perpendicular to direction of sheets of the next rolling. Rolling of the pack is performed till a final size, and then, obtained sheets are removed from it and finishing operations are performed.
EFFECT: obtaining a microstructure of sheets, which provides high and uniform level of strength and plastic properties.
1 dwg, 2 tbl
The invention relates to the processing of metals by pressure, and in particular to methods of manufacturing thin sheets of pseudo-alpha titanium alloys for the manufacture of parts of aircraft.
A known method of manufacturing parts of the pseudo-alpha titanium alloys, including heat in the beta region above the temperature of polymorphic transformation (hereinafter CCI), cooling, re-heating in the two-phase region, repeated deformation in this region during the cooling process, re-cooling, the final heating in the two-phase region, the shutter speed and cooling (A.S. USSR №1740487, publ. 15.06.1992). The known method is intended for manufacturing of forged and stamped products and not optimized for a sheet of semi-finished products.
A known method of manufacturing sheets of low-alloy titanium alloys, including heat flat ingot, hot rolling the strips, cut strips on the billet, heating the billet in a two-phase region, rolling them on the sheets, heat treatment, etching, editing, cutting sheets to finished size (patent RF №2198237, publ. 10.02.2003). The known method does not take into account technological features pseudo-alpha titanium alloys.
A known method of manufacturing a particularly thin sheets of high-strength titanium alloys, including the production of the original sheet, the collection is a package of sheet blanks with obmazyvaem coating using case hot rolling and heat treatment batch, split and finish of the obtained sheets (Patent RF №2381297, publ. 10.02.2010) prototype. However, in the known method are not regulated modes of thermomechanical processing, which does not allow for a given level of mechanical properties and structure.
The problem to which the invention is directed, is the development of a method for manufacturing thin sheets of pseudo-alpha titanium alloys having a homogeneous structure and mechanical properties, and high surface quality and geometrical parameters.
The technical result achieved in the implementation of the invention is to obtain the microstructure of sheets, providing a high and uniform level of strength and plastic properties.
This object is achieved in that in the method of manufacturing thin sheets of pseudo-alpha titanium alloys, including deformation of the ingot into a slab, machining slab, rolling slab on steel, cutting steel into billets, rolling blanks on worksheets and adjusting operations according to the invention for the manufacture of sheets use the slab obtained from the deformed ingot after heating to a temperature of 150÷250°C higher CCI with a total degree of deformation of 30÷60% and after heating at 100÷200°C above the CCI with a total degree of deformat and 40÷70%, perform multi-pass rolling slab on steel by heating to a temperature of 90÷150° above the chamber of Commerce with the degree of deformation per pass 10÷20% and additional heating after reaching the degree of deformation 25÷35% when the total deformation at this temperature, 50÷80%, heating to a temperature of 30-60°With the lower chamber of Commerce with the degree of deformation per pass 5÷10%, when the total deformation at this temperature, 15÷25%, heating to a temperature of 80÷120°C above the chamber of Commerce with the degree of deformation per pass 10÷20% and more the heating after reaching the degree of deformation 25÷35% when the total deformation at this temperature, 50÷80%, heating to a temperature of 50÷70°C lower chamber of Commerce with the degree of deformation per pass 5÷10% and an additional heating after reaching the degree of deformation 15÷25% of the total deformation at this temperature, 40÷65%, then perform the cutting of rolled sheet metal workpiece and adjusting the operation, Assembly, sheet blanks in the package so that the direction of the leaves of the previous rolling was perpendicular to the direction of the sheets subsequent rolling, rolling package the finished size with heating to a temperature of 70÷100°C lower chamber of Commerce with the degree of deformation of the package for the passage 10÷20% and additional heating of the package after reaching the degree of deformation 25÷35% when the total deformation of the package 55÷70%.
The method is implemented the trail the way.
Produced and machined cylindrical ingot is heated to a temperature of 150÷250°C higher chamber and subjected to forging, with a total degree of deformation of 30÷60%, which destroys the cast structure, averages the chemical composition of the alloy, compacting the workpiece, eliminating such casting defects such as voids, sinks and other Temperature below the specified limit leads to the reduction of plastic characteristics, the difficulty of deformation and the appearance of surface cracking, the heating temperature is above the specified limit causes a significant increase in gas-saturated layer, which leads to superficial lacerations during deformation, deterioration of the metal surface and consequently to increased metal removal with the billet surface. The following strain with a total degree 40÷70% after heating at 100÷200°C above the CCI allows multiple grind the grain size relative to the initial state. For complete removal of surface defects resulting slab mechanical process from all sides. Further multi-pass rolling of the slab to tackle with the total degree of deformation of 50÷80% after heating to a temperature of 90÷150°C above the CCI increases the ductility of the metal and limits the formation of defects during subsequent deformation in the (α+β)region. The slab is rolled with the degree of deformation is then for the passage 10÷20%, and after reaching the degree of deformation 25÷35%, produce additional heating, which improves the ductility of the metal, to keep the process rolling satisfactory surface quality and to avoid the formation of cracks. After deformation β is effected by heating to a temperature of 30÷60°C lower chamber of Commerce and carry out multi-pass rolling with a total deformation 15÷25% for the destruction of large angle grain boundaries, increasing the density of dislocations, i.e. they perform the deformation hardening. The degree of deformation per pass 5÷10% is determined by technological properties of alloys at this temperature deformation. The resulting metal has a higher internal energy and subsequent heating to a temperature of 80÷120°C above the CCI with the total deformation 50÷80% is accompanied by recrystallization from grinding grain, allowing you to get in the workpiece being machined equiaxial macasero. Then take further rolling with level 40÷65% after heating at 50÷70°C lower chamber of Commerce to prepare a given microstructure to obtain the mechanical properties in the transverse direction, to the further batch rolling to produce the preparation of the microstructure to obtain the mechanical properties mainly in the longitudinal direction. The degree of deformation per pass 5÷10% is determined by the technology the properties and conditions of achievement of the minimum thickness variation of the sheet workpiece before the batch rolling. At this stage, after reaching the degree of deformation 15÷25% produce additional hot rolled, allowing you to maintain a satisfactory surface quality.
In the absence of the possibility of applying cold rolling to obtain thin sheets because of the low ductility of the alloys and high loads on the mill because of the high deformation resistance of the final deformation of the sheets on the finished size is carried out by the batch method, for which the rolled cut-to-length sheet, while the sheet stack in the direction of rolling so that the direction of the subsequent rolling was perpendicular to the previous direction of rolling. Changing the direction of rolling of the package allows to obtain optimal crystallographic texture in the leaves and reduce the anisotropy of mechanical properties. Temperature range heating (heating at 70÷100°C higher CCI) and the degree of deformation at this stage 55÷70% can increase the level grinding and coagulation of primary α-phase, which contributes to obtaining equiaxial fine micrograins, providing uniform mechanical properties in all directions. After the batch rolling the sheets removed from the package and carry adjusting processing, test sheets and in which akuku.
Industrial applicability is confirmed by specific example of carrying out the invention.
To obtain sheets of thickness 2 mm were smelted ingots of pseudo-alpha titanium alloy with a diameter of 540 mm weight 740 kg
The chemical composition of the alloy is given in table 1. The temperature of polymorphic transformation alloy 1008°C.
|The sampling location sample||Mass fraction of elements, %|
The ingot was subjected to forging by flattening by forming a thickness of 250 mm after heating to 1200°C (190°C higher CCI) with deformation rate of 53%. Then the billet was heated to a temperature of 1150°C (140°C above CCI) and has been forging a billet of rectangular cross section with dimensions of 130×680×1700 mm with a total degree of deformation of 55%. Further forged slab struck at the size 117×680×1100 mm Slab was heated to the set temperature of 1130°C (120°C higher CCI) and rolled for 2 passes with the degree of deformation in each pass, respectively 16.3% and 10.6% of mm, then when reaching the total deformation for heating 30% tackle was heated at the same installation temperature. Further rolling was carried out as previously described for a thickness of 30 mm, the total degree of deformation at the stage of 74.4%. To improve the surface quality of the rolled subjected to mechanical treatment (solid abrasive cleaning) with the removal of 0.30 mm on the side. Next, the strips were heated to a temperature of 970°C (40°C below CCI) and p is oizvodil rolling in 2 passes for 25 mm thick with degrees of deformation in each pass, respectively, 10% and 7.5%, with a total deformation of 15%. Further rolling was carried out at a temperature of 1100°C (80°C higher CCI) at a thickness of 12 mm Rolling was carried out in 2 passes with degrees of deformation in each pass, respectively, 10 and 20% and, after reaching the accumulated strain of 30% was carried out by heating at the same temperature. The total deformation rate was 58%. Further rolling was carried out at a temperature of 950°C (60°C below CCI), rolled for 2 passes to a thickness of 10 mm with a degree of deformation of 5÷10% in each pass with total degree of deformation of 15%. Further, the rolling was carried out at a temperature of 950°C (60°C below CCI), rolled for 2 passes to the thickness of 8.5 mm with a degree of deformation of 5÷10% in each pass with total degree of deformation of 15%. Further, the rolling was carried out at a temperature of 950°C (60°C below CCI), rolled for 2 passes to the thickness of 7.3 mm, with a deformation rate of 5÷10% in each pass with total degree of deformation of 15%. Further, the rolling was carried out at a temperature of 950°C (60°C below CCI), rolled for 2 passes to the thickness of 6.2 mm with a degree of deformation of 5÷10% in each pass. The total degree of deformation at a temperature of 950°C was 49%. Then the rolled cut-to-length sheet, spent adjusting operation and collecting the bags, when this sheet was placed in the package so that the direction of the subsequent use of the TCI was perpendicular to the previous direction of rolling. In the package was placed on sheet 3 of the workpiece, taking into account the upper and lower steel plates of a thickness of the package accounted for 50.9 mm Then perform the final stage of rolling the batch method, for which the package was heated to a temperature of 920°C (90°C below CCI) and rolled for 2 passes to the thickness of 38.5 mm (degree of deformation 16% and 10% in the aisles). Then was carried out by heating and rolling for 2 passes on the thickness of the package 29 mm (degree of deformation of the passages 16% and 10%, the total degree of deformation of 24.7%), followed by manufactured heating and rolling of the package for 2 passes on the thickness of the package 22 mm (degree of deformation of the passages 16% and 10%), the overall degree of deformation 24.0%), and then carried out the heating and rolling for 2 passes on the thickness of the package 16 mm (degree of deformation of the passages 16% and 13%, the total deformation of 27.2%). The total degree of deformation of the package was 61%. Then carried out the disassembly of packets, resulting in the obtained sheet sizes 2,3÷2,4×900÷910×2900÷2950 mm
The obtained sheets were produced by adjusting the processing, cutting to final size, sampling and testing of mechanical properties and study patterns. The results of testing the mechanical properties of the sheets are given in table 2, images of the microstructure of the sheets is presented in figure 1. The surface quality of sheet met all the requirements of normative documents, cracks and race is of loani not recorded.
|The condition of the test sample||Mechanical properties|
|The yield strength, σof 0.2, MPa||Tensile strength, σin, MPa||Elongation, δ,%|
|Longitudinal direction||Transverse direction||Longitudinal direction||Transverse direction||Longitudinal direction||Transverse direction|
|After the heat treatment regime: 930°C - exposure 60 minutes air cooling||927||903||1001||983||15,8||14,8|
|After the heat treatment regime: 950°C - exposure 60 minutes air cooling||922||908||991||989||15,2/td>||14,3|
Thus, the present invention compared to the known methods, can be obtained from pseudo-alpha titanium alloy thin sheets with a high level of mechanical properties with minimal anisotropy and a homogeneous structure and a satisfactory surface quality.
A method of manufacturing thin sheets of pseudo-alpha titanium alloys, including deformation of the ingot into a slab, machining slab, multi-pass rolling slab on steel, cutting steel sheet billets, their Assembly into the package and its rolling and adjusting operation, characterized in that the deformation of the ingot in the slab is carried out by heating it to a temperature of 150÷250°C higher than the temperature of polymorphic transformation (CCI) and deformation from the total deformation rate 30÷60%, subsequent heating to a temperature of 100÷200°C higher CCI and deformation from the total deformation rate 40÷70%, multi-pass rolling of the slab is carried out in several stages, in which the slab is heated to a temperature of 90÷150°C higher CCI and rolled with a total degree of deformation at this temperature, 50÷80%, statutorily for passage 10÷20% and additional heating after reaching the degree of deformation 25÷35%, the strips are heated to a temperature of 30÷60°C lower chamber of Commerce and rolled with a total degree of deformation at this temperature, 15÷25% and the degree of deformation per pass 5÷10%, steel is heated to a temperature of 80÷120°C higher CCI and rolled with a total degree of deformation at this temperature, 50÷80%, degree of deformation per pass 10÷20% and additional heating after reaching the degree of deformation 25÷35%, steel is heated to a temperature of 50÷70°C lower chamber of Commerce and rolled with the total deformation at this 40 ° ÷65%, degree of deformation per pass 5÷10% and an additional heating after reaching the degree of deformation 15÷25%, after cutting the strips on the sheet hold their auxiliary operations, Assembly, sheet blanks in the package is done by laying so that the direction of the leaves of the previous rolling was perpendicular to the direction of the sheets subsequent rolling, rolling package the finished size lead by heating to a temperature of 70÷100°C lower chamber of Commerce and rolling with a total degree of deformation 55÷70%, the degree of deformation per pass 10÷20% and additional heatings package after reaching the degree of deformation 25÷35%, then from the package, remove the sheets and carry out auxiliary operations.
SUBSTANCE: ingot is subjected to swaging-drawing to octahedron with total reduction of 1.6-1.7. Final forming is performed at shaped hammers at 4-5 displacements over hammer surface and, then, in closed sizing die. Total reduction ay final forming makes 3-5.
EFFECT: precise forged pieces with homogeneous fine-gram structure, high specific strength and ductility.
2 cl, 2 tbl, 1 ex
SUBSTANCE: proposed alloy features density at a room temperature of not over 4.2 g/cm3, solidus temperature of at least 1450°C, the number of phases α2 and γ at 600-800°C making at least 20 wt % and at least 69 wt %, respectively. Total quantity of said phase makes at least 95 wt % while niobium content in γ-phase makes at least 3 wt %. Proposed method consists in that said γ-TiAl alloy containing niobium in amount of 1.3 or 1.5 at. % and transition metals selected from chromium in amount of 1.3 or 1.7 at. % and zirconium in amount of 1.0 at. % is subjected to hot isostatic forming. Said forming is combined with annealing at 800°C and holding for 100 hours.
EFFECT: low density, stable phase composition at operating temperatures.
2 cl, 2 dwg, 4 tbl, 1 ex
SUBSTANCE: proposed process of production of cages for prosthetic cardiac valves from commercially pure titanium comprises assembly and soldering of drawn wire and plate and thermal treatment. Prior to assembly, wire is annealed in vacuum furnace at 550-600°C for 30-40 minutes and cooled with furnace. After soldering, the cage is annealed in vacuum furnace at 550-600°C for 1.5-2 hours and cooled with furnace.
EFFECT: better manufacturability, lower labour input, high mechanical properties.
1 tbl, 1 ex
FIELD: process engineering.
SUBSTANCE: invention relates to metal forming and can be used for production of turbo machine thermomechanical part from beta- and/or alpha/beta-titanium alloy. Forged piece of the part is made from titanium alloy ingot with temperature Tβ of conversion into beta-phase. Note here that at least one ingot rough forging step is effected at temperature T1 lower than temperature Tβ of conversion into beta-phase. In forging, the ingot is plastically deformed to ensure local deformation at all points of at least 0.2. Produced ingot is cooled down and subjected to final fording at T2 higher than temperature Tβ of conversion into beta-phase. Produced forged piece is cooled down.
EFFECT: forged piece with fine and homogeneous grain size of about 50-100 mcm.
14 cl, 3 dwg
SUBSTANCE: workpieces are made in the form of rings; deformed so that thicknesses of their walls are reduced and their diameter is increased, and then, their ends are butt welded till a pipe is obtained. Deformation of rings with wall thickness reduction is performed by rolling on a ring-rolling mill or by forging on a mandrel using forging equipment. Radial texture is preserved throughout the pipe length.
EFFECT: producing a pipe from technically pure titanium with radial texture.
3 cl, 6 dwg, 2 ex
SUBSTANCE: invention relates to metallurgy. proposed method of treatment of said allows completely hardening in β-phase containing alloying elements, at least, boron and elements stabilising β-phase comprises cooling the blanks from temperatures of β-phase region. Blanks are cooled immediately after gardening or after heating and curing at temperatures of β-phase region. Note here that blanks are cooled to temperatures of (α+γ)- or (α+β+γ)-phase depending on size in air or in air in container to form thermodynamically nonequilibrium structure but at the rate smaller than that of cooling at tempering of alloy selected composition. The, blanks are cooled from temperatures of (α+γ)- or (α+β+γ)-phase region to room temperature together with the furnace or cooled in air with subsequent annealing at temperatures of (α+γ)- or (α+β-γ)-phase region and cooling after annealing together with the furnace.
EFFECT: higher performances and processing ductility.
5 cl, 5 dwg, 7 tbl, 3 ex
SUBSTANCE: proposed alloy features structure of nanocrystalline grains of B2-phase wherein volume fraction of 0.1 mcm-size grains and those of shape factor of 2 in mutually perpendicular planes makes at least 90%. Over 50% of grains have large angular boundaries misaligned relative to adjacent grains through 15 to 90 degrees. Method of making the bar from said alloy comprises thermomechanical processing including plastic straining and recovery annealing. Intensive plastic straining is made in two steps. At first step, equal-channel angular pressing is made to accumulated strain e≥4. At second step, forge ironing and/or drawing are made. Annealing is carried out either in process and/or after every straining step. Equal-channel angular pressing is performed at 400°C. Forge drawing and ironing are made to total reduction of over 60% at gradual decrease of temperature to t=450-200°C, while annealing is performed at t=400-200°C.
EFFECT: higher mechanical and functional properties.
2 cl, 2 dwg, 1 ex
SUBSTANCE: heat treatment method of castings from alloys based on gamma titanium aluminide involves hot isostatic pressing, cooling to room temperature and further heating at temperature below eutectoid alloy conversion. Hot isostatic pressing is performed at the temperature above eutectoid alloy conversion in α+β+γ phase area at the following number of phases in alloy, wt %: beta phase (β) 7 to 18, gamma phase (γ) 5 to 16, and alpha phase (α) is the rest.
EFFECT: shortening the time required for heat treatment; with that, alloys have high level of mechanical properties.
2 cl, 2 dwg, 1 tbl, 1 ex
SUBSTANCE: prior to drawing a wire heating method involving dosed heating with infrared emission flow before a drawing block differs by the fact that dosed heating is performed by selecting semiconductor emitting diodes located around the drawing block and having directed emission characteristic, the maximum of which is oriented to wire axis; with that, dosed heating is performed by changing feed current of emitting diodes.
EFFECT: improving wire quality owing to reducing probability of occurrence of defects and breaks.
SUBSTANCE: proposed method comprises processing the workpiece in explosive accelerator by high-velocity Ti powder particle flow in the mode of super deep penetration of particles. Note here that Ti particles are arranged under explosive with air gap. Acceleration of articles is carried out by shock wave in accelerator guide channel coupled with processed workpiece. Processing is performed by flow of particles with dispersity of 20 mcm at flow rate of 1.5-2.5 km/s, density of 1 g/cm3, pressure of collision of particles with workpiece material of 12-15 GPa and their interaction time of 5-7·10-5 s.
EFFECT: higher strength and homogeneity of titanium workpiece structure.
SUBSTANCE: method includes heating of a flat stock and its multi-pass pressing in working rollers. Exclusion of formation of internal defects in rolled metal is achieved by the fact that heating of the stock is carried out to temperature of 750-850°C, and pressing in each of passes is regulated by mathematical dependence.
EFFECT: increased quality of thick-sheet rolled metal from hard-to-deform copper alloys with lower process plasticity.
1 tbl, 6 ex
SUBSTANCE: in compliance with proposed method of rolling thin bands from aluminium Al-Mg or Al-Mg-Mn system alloys fully recrystallised hot-rolled band blank is subjected to rolling. Band blank features cubic texture and depth 9-10 times larger than band final depth. Rolling causes 45-47% reduction at every of two last passes at deformation rate of at least 10 m/s and band coiling temperature of 140-160°C, coil weight making at least 8 t.
EFFECT: higher metal ductility, decreased scatter of mechanical properties.
SUBSTANCE: proposed method comprises hot forming of slab, hot rolling and teat treatment of plate, whereat hot forming if carried out in one step. Immediately after reaching required thickness in slab forming it is quickly cooled to the depth of 20-30 mm at the rate of at least 50°C/min. Subsequent hot lengthwise rolling at performed at first step in α+β-area by partial reduction with deformation degree εi varying from 3% to 5% to total deformation ε=25…30% with breaks between passes of 8 to 12 s. At second step, it is performed in β-area from heating temperature determined by definite formula. At the next step rolling is performed in α+β-are with breaks and heating in lengthwise or transverse directions with total degree of deformation e after every break to 60%.
EFFECT: homogeneous fine-grain microstructure, high and stable mechanical properties, high precision, no surface defects.
SUBSTANCE: invention relates to production of thin sheets from ingot of pseudo-alpha titanium alloy. Proposed method comprises forming ingot of alloy Ti-6.5Al-2.5Sn-4Zr-1Nb-0.7Mo-0.15Si into slab and machining of the latter. Then, said slab is heated to temperature exceeding that of polymorphic transition, deformation and multistep rolling to semi-finished rolled stock with regulated total degree of deformation and degree of deformation in a pass. Sheets are stacked, stacks are rolled to finished size and subjected to multipass rolling with regulated total deformation, sheets are extracted from the stack and subjected to finishing.
EFFECT: high and uniform strength and plastic properties.
1 dwg, 2 tbl
SUBSTANCE: proposed method comprises smelting of alloy, making slab, machining its surface, hot, warm, and cold rolling, sintering and ageing. Smelted is pseudo-beta-titanium alloy with aluminium content not higher than 5.0 wt % and molybdenum equivalent No eq. ≥ 12 wt %, calculated by the following formula: Mo eq. wt % = %Mo + %Ta/4 + %Nb/3.3 + %W/2 + %V/1.4 + %Cr/0.6 + +%Fe/0.5 + %Ni/0.8 + %Mn/0.6 + %Co/0.9. Semi-finished 8-2 mm-thick rolled stock produced in hot and cold rolling is subjected, prior to cold rolling, to quenching at Tpt+(20-50°C) for 0.1-0.5 h with cooling. Cold rolling is performed to sheet thickness of 6-1 mm in signal-phase beta-state in two and more steps in several passes with 1-6%-reduction in one pass and total reduction at every step of 30-50%. Note here that intermediate quenching is carried out between said steps in conditions identical to quenching of semi-finished rolled stock before cold rolling.
EFFECT: high-quality rolled thin sheets.
5 dwg, 2 tbl
FIELD: process engineering.
SUBSTANCE: invention is intended for increasing quality of sheets and ruling out pollution originating in forming special magnesium alloys doped with high-toxicity light-volatile elements that form, in heating and forming, harmful oxides, and may be used in production of sheets for anodes of electrochemical current sources. Proposed method comprises placing round ingot in tubular shell, hearing the workpiece and its hot and warm rolling to requited sheet thickness.
EFFECT: higher quality of sheets and process efficiency.
FIELD: process engineering.
SUBSTANCE: invention relates to metallurgy, particularly, to forming semis from titanium alloy BT6 and may be used in machine building, aircraft engineering and medicine. Proposed method comprises annealing at 850°C with holding for an hour in furnace to create globular (α+β)-structure and multipass rolling combined with affecting semis to pulsed electric current with density of 50-200 A/mm2, frequency of 830-1000 Hz, pulse duration of 100-120 ms to ensure total true strain degree of e>1 and to form nanocrystalline structure in semi. Note that, after every pass, semi is water cooled. Higher forming capacity of alloy is provided for.
EFFECT: higher strength at optimum ductility.
5 cl, 1 dwg, 1 tbl, 1 ex
FIELD: process engineering.
SUBSTANCE: proposed method comprises making ingots or powder billets. The latter are subjected to hot thermo mechanical machining, including sandwich rolling and finish cold rolling. Foil material mechanical properties are stabilised and material structure is blended in sandwich rolling at semi-finished rolled stock thickness of 2-4 mm with premade fine structure wherein grain width does not exceed 10 mcm while its length makes 40 mcm. Sandwich is composed of a set of semi-finished rolled billet and two steel covering plates. Note here that top covering plate thickness is 1.4-1.8 times larger than that of bottom plate. Hot rolling of sandwich is started from 950±50°C in several passes with total deformation of 70-90%. After annealing at 920±70°C and sandwich disassembly, cold rolling of every billet is performed at total deformation of 40-70% with intermediate vacuum annealing at 920±70°C.
EFFECT: higher foil quality made from titanium aluminide-based alloys based on Ti2AlNb orthorhombic phase.
2 cl, 4 dwg, 2 tbl
FIELD: process engineering.
SUBSTANCE: proposed method comprises stage-by-stage grinding of titanium billet grains by abc-forming and multi-pass rolling in grooved rolls with stepwise reduction in groove section at fixed temperature of billet heating for rolling. Increased mechanical properties are ensured by stepwise grain grinding at stepwise temperature reduction in the range of 750-500°C. In abc-forming, titanium billets made be subjected to recrystallisation annealing at 680-700°C for 1 h. Rolling in grooved rolls is performed at reducing billet temperature by 40-60°C at every pass to groove smaller section from 500°C to 300°C whereat rod final round cross-section is formed. The number of groove cross-sections id selected to provided for reduction not exceeding 40% in transition from one groove to another. Rolling is performed in several passes on turning the billet through 90 degrees about lengthwise axis. 4-8 mm-dia round titanium billets are produced to meet high purity standards.
EFFECT: higher metal yield.
6 cl, 2 tbl, 3 ex
SUBSTANCE: method to manufacture cold-deformed pipes from double-phase alloys based on titanium includes ingot smelting, ingot forging in a β-area or β- and α+β-area with forging completion in the α+β-area into an intermediate blank with the specified forging reduction. The intermediate blank is produced with forging reduction of at least 1.35, a block is made from the intermediate blank, which is pressed into a billet and thermally treated at the temperature that is by 30°-40°C below the temperature of Tint, and them the billet is rolled with intermediate surface treatment, etching and thermal treatment. Drawing in process of rolling is defined using the following formula.
EFFECT: produced pipes are characterised by high physical-mechanical properties due to exclusion of formation of grain-to-grain microcracks.
4 tbl, 1 ex
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