Method for producing pipe from technically pure titanium with radial texture
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
The proposed method relates to the field of metallurgy, and in particular to methods of creating textured status of materials having a hexagonal close-Packed crystal lattice, in the main, such as alpha-titanium.
Basically, in the tubes from titanium and zirconium alloys are trying to get the radial texture of the metal, due to their better resistance against the development of cracks.
Further explanation of the circumstances connected with textured state, will use the notion of parameters Cairns (J.J. Kearns On the relationship among 'f' texture factors for the principal planes of zirconium, hafnium and titanium alloys. Journal of Nuclear Materials. 2001. V.299. No. 2. P.171-174).
The prior art method for the production of pipes made of materials able hexagonal close-Packed lattice, then the GPU-grid (U.S. patent US 4765174. Texture enhancement of metallic tubing material having a hexagonal close-packed crystal structure / Cook Charles S, Sabol, George P. the Applicant Westinghouse Electric Corporation [US]. IPC B21B 21/00, B21C 37/06, B21C 37/30. Publ. 1988-08-23. Priority 1987-02-20).
A method is proposed to use the operation of reducing the diameter of the pipe with a simultaneous decrease in wall thickness. This leads to the achievement of the deformation in the radial direction (εr<0) and the same compression deformation in the tangential direction (εφ<0) in the presence of tensile strain along the length of the workpiece. The presence of compressive deformation the radial direction leads to the formation of radial texture and increasing the value of Cairns f rfrom 0.33 characteristic retexturising state, to 0.5.
In the description of the patent, however, noted that the best option is the formation of a schema deformation in the radial direction (εr<0) and tensile strain in the tangential direction (εφ>0). This is achieved through the operation of increasing the pipe diameter with decreasing wall thickness. The presence of such schemes strain state can give a more acute radial texture in the workpiece and to increase the parameter Cairns responsible for the radial component.
In particular, by using the described intake can increase the parameter Cairns in the radial direction frto a value of 0.66. This achievement is made due to the fact that the implemented scheme deformed state, in which there is only one strain compression (when two tensile deformations), which is directed along the radius of the workpiece.
In particular, these studies found that the compression with logarithmic degree of deformation of the wall, εr=-εφ=- 0.1 parameter Cairns frincreases in the value of 0.12.
The closest to the essential features of the claimed object (the prototype) is a method for the production of titanium tubes (U.S. Patent No. 5332454. Titanium or titanium based alloy corrosion resistant tubing fom welded stock / Meredith Steven E., Benjamin James F. the Applicant Sandvik Special Metals [US]. IPC C22F 1/18. Publ. 1994-07-26. Priority from 1992-01-28).
The method involves receiving pipes of commercially pure titanium with a radial texture and includes obtaining hollow workpieces, their deformation and welding. Including the method includes flat rolling stepsaway (sheet) blanks, folding it into the pipe, the sealed edges of the longitudinal welding. The essence of this technical solution is that when the flat rolling a deformed state, in which the thickness of the sheet creates a deformation ratio, and the length of the workpiece - deformation strain. The width of the workpiece deformation is absent due to the presence of schema plane deformation. For metals with HCP lattice texture is created in the direction of creating a strain compression. Because during rolling deformation were directed by the thickness of the blank, after coagulation tubes these deformations turned into a radial, which led to the creation of radially oriented texture.
The disadvantage of the prototype is the inability to save textured condition along the circumference of the pipe due to the presence of a longitudinal welding seam, in which the radial texture is not formed.
In addition, the longitudinal seam is poorly resists the action of tangential stresses PR is the use of pipes under the action of high pressure, and this is the purpose of the pipes.
The proposed method of producing pipes of commercially pure titanium with a radial texture includes obtaining hollow workpieces, their deformation and welding. It differs in that the gain of the workpiece in the form of rings, the ring is deformed to reduce the thickness of their walls and increase in diameter and weld ends butt weld with getting a pipe.
Deformation rings with decreasing wall thickness is performed by rolling on the ring rolling mill.
In another embodiment, the deformation of rings with decreasing wall thickness exercise forging mandrel for forging equipment.
The essence of the proposed technical solution is the following. During rolling of rings is achieved by deformation of the extension in the tangential direction (εφ>0), the compression deformation in the radial direction (εφ<0), and deformation elongation in a high-rise direction is missing (εz=0). Thus, in this scheme, the strain state are one warp elongation and one shorter. When this radial texture is formed along the axis of shortening, i.e. in the radial direction.
The weld seam is not along the longitudinal direction and along the transverse direction, is not dangerous from the standpoint of destruction from the action of tangential stresses. In addition, in this case n is t violations prior texture along the circumference of the pipe, since the welding seam is not directed along the pipe, and is made in the transverse direction.
Figure 1 shows the profile of the original piece. Figure 2 shows the scheme of ring rolling. Figure 3 shows in the form of an elementary volume of a cube with schema directions of deformation. Figure 4 shows a ring of enlarged diameter. Figure 5 shows the diagram of the welding rings of enlarged diameter. Figure 6 shows the scheme of forging rings.
The method is as follows. At the first stage hollow billet 1 (figure 1) is made in the form of rings using well-known methods of processing metals by pressure, for example, a method of pressing and subsequent cutting to length. In the second stage of preparation in the form of rings is subjected to deformation with decreasing wall thickness of the rings and receiving of rings increased diameter. Reducing the wall thickness of the rings, and receive rings of enlarged diameter, carried out by rolling on the ring rolling mill. Figure 2 shows that the workpiece 1 is deformed two rolls, the outer roller 2 is located on the outer surface of the hollow billet 1, and the inner roller 3 is located inside the cavity of the ring. Joint compression rolls, the wall thickness of the workpiece decreases, and the diameter of the workpiece increases. Figure 3 shows in the form of a cube elementary volume 4 metal billet in the process. Compression of the billet proishodit the direction of the radius, therefore, the deformation εr<0 and are deformations of compression. Billet size in the tangential (Cordova) direction increases, therefore, the deformation εφ>0 and deformations are lengthening. Figure 4 shows a ring of enlarged diameter 5, which has a wall thickness reduced relative to the original size. At the third stage (figure 5) ring of enlarged diameter butt weld (weld areas designated as 6), resulting in the pipe 7.
A variant of this method is the replacement of admission rolling rings for the reception of forging rings. Figure 6 shows that the die or the press plate 8 acts on the outer diameter of the hollow billet 1, and the inner diameter of the workpiece based on the fixed mandrel 9. As a result of such exposure, the wall thickness is locally reduced and the diameter of the workpiece increases. After removal of firing pin 8 of the workpiece 1 is turned at a given angle, and the compression process is repeated, achieving a uniform deformation along the circumference of the workpiece.
Example 1. At the first stage receives the procurement of commercially pure titanium in the form of rings. For this purpose a hollow workpiece outer diameter of 60 mm and an inner diameter of 50 mm is cut to length and get a ring with a wall thickness of 5 mm At the second stage of preparation in the form of rings is subjected to deformation at Calabro atom mill with reduction of wall thickness up to 4.5 mm Thus the outer diameter of the ring is increased to 65.6 mm, and the inner to 56.6 mm, the Degree of deformation of the wall is εr=-εφ=-0,1. Thus, the degree of deformation, which, as was shown above, the parameter Cairns frincreases in the value of 0.12, i.e. acuity is increased radial texture. In the third phase of the received ring of enlarged diameter weld ends butt weld with getting a pipe.
Example 2. At the first stage receives the procurement of commercially pure titanium in the form of rings. For this purpose a hollow workpiece outer diameter of 60 mm and an inner diameter of 50 mm is cut to length and get a ring with a wall thickness of 5 mm At the second stage of preparation in the form of rings is subjected to deformation in the ring rolling mill with reduction of wall thickness up to 4 mm While the outer diameter of the ring is increased to 72.8 mm, and the inner to 64.8 mm, the Degree of deformation of the wall is εr=-εφ=-0,2. There was twice higher degree of deformation, which, as was shown above, the parameter Cairns frincreases in the value of 0.24, i.e. acuity is increased radial texture. In the third phase of the received ring of enlarged diameter weld ends butt weld with getting a pipe.
It should be noted that the textured condition in the method prototype for a length of the first circumference of the pipe was broken due to the presence of a longitudinal welding seam, in the proposed method, this is not the case, since the longitudinal welding seam is missing.
The technical result consists in achieving and maintaining textured condition along the circumference of the pipe.
1. The way to get the pipe out of commercially pure titanium with a radial texture, including the production of hollow workpieces, their deformation and welding, characterized in that the gain of the workpiece in the form of rings, the ring is deformed to reduce the thickness of their walls and increase in diameter and weld ends butt weld with getting a pipe.
2. The method according to claim 1, characterized in that the deformation of rings with decreasing wall thickness is performed by rolling on the ring rolling mill.
3. The method according to claim 1, characterized in that the deformation of rings with decreasing wall thickness exercise forging mandrel for forging equipment.
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: high-strength pseudo-beta titanium alloy contains the following, wt %: aluminium 5.3-5.7, vanadium 4.8-5.2, iron 0.7-0.9, molybdenum 4.6-5.3, chrome 2.0-2.5, oxygen 0.12-0.16, and titanium and impurities are the rest, and when necessary, one or more additional elements chosen from N, C, Nb, Sn, Zr, Ni, Co, Cu and Si; with that, each additional element is present in the amount of less than 0.1%, and total content of additional elements is less than 0.5 wt %. At production of alloy, after it is obtained, homogenisation is performed at the temperature below temperature of beta-conversion and its disperse strengthening. An aviation system component represents a landing gear or a fastening part, which is made using titanium alloy.
EFFECT: alloy has high strength,ductility and ability for deep hardening.
25 cl, 4 dwg, 3 tbl, 3 ex
SUBSTANCE: method of processing the titanium alloy consisting of, at least, the following components, in wt %: iron - 0.2-0.5, oxygen - 0.02-0.12, silicon - 0.15-0.6, titanium and unavoidable impurities making the rest, comprises executing the first thermal treatment at first temperature to form the structure containing 50% of beta-phase, and, then, cold rolling. Second thermal treatment at second temperature is executed to produce second-phase precipitation while third thermal treatment is performed at third temperature for alloy recrystallisation without dissolution of precipitation.
EFFECT: high-strength titanium alloy with high resistance to oxidation and pliability at low temperatures.
18 cl, 6 dwg
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: soaking is done at heating temperature for 10-15 minutes, and cooling is done in a coolant with speed of 300°C/s, afterwards ageing is done under load at 18-25°C, stress not exceeding yield point at ageing temperature, and time required to achieve stable speed of relaxation process.
EFFECT: increased strength of titanium of BT1-0 grade in combination and higher plasticity during treatment of items from titanium BT1-0, including heating, is carried out to temperature exceeding temperature of polymorphous transformation.
1 tbl, 1 ex
SUBSTANCE: invention refers to nanostructured materials with ultra-fine grain structure, and namely two-phase alpha-beta titanium alloys which can be used for manufacture of semi-finished products and products in different branches of engineering, machine-building industry and medicine. Proposed alloy has microstructure consisting of ultra-fine grains of alpha-phase and beta-phase with the size of less than 0.5 mcm. In alloy microstructure the amount of grains with grain shape coefficient of not more than 2 is not less than 90%; at that, more than 40% of grains have wide-angle borders, and average density of dislocation is not more than 1014 m-2. the method for obtaining ultra-fine grain two-phase alpha-beta titanium alloy involves heat treatment with heating of a billet at the temperature of not more than 0.6 T"пп", further multicycle intense plastic deformation with achievement of accumulated true deformation degree e≥4. Then, plastic deformation is performed so that the billet shape is changed at the rate of less than 10-1 s-1 in several cycles to provide deformation degree ε≥50%.
EFFECT: improving strength and fatigue properties and preserving high ductility.
5 cl, 2 dwg, 1 tbl, 1 ex
FIELD: process engineering.
SUBSTANCE: invention relates to contact butt welding. Manipulator with distance transducers fitted thereat is fed into rail ends abutting area to correct rail end clamped position with the help of servo gears by driving them vertically and horizontally. Said manipulator is made abut tightly on rolling surface and side face of one of the rails by electromagnets. Said one rail is taken to make a reference base. Used error signal represents the difference in spacing from reference base to rolling surface and from reference base to side rail faces measured by distance transducers.
EFFECT: fast and stable alignment.
FIELD: process engineering.
SUBSTANCE: invention relates to production of welded tubes. Displacing metal strip is bent by rolls to cylindrical shape to weld its ends together by welding unit. Welding unit power supply is located nearby said bent metal strip and composed of induction heater or device of heating by passing current for heating metal strip both ends. Pressure rollers weld heated strip ends together by bringing them in contact and pressing against each other. Ferromagnetic body slides between said ends and is arranged in the section of clearance along metal strip displacement and upstream thereof with respect to said power supply.
EFFECT: higher efficiency of heating owing to increased magnetic field and current density.
14 cl, 27 dwg, 3 tbl, 9 ex
FIELD: process engineering.
SUBSTANCE: welding head can be used for making butt welding of two extreme ends of track two sections. Two welding head halves 10 are opposed to slide relative to each other in lengthwise direction. Every said half has rail grippers 12, 13. At least two electrodes 16 are connected in electric welding circuit to ensure contact with appropriate rail section. Drives 20 extend in lengthwise direction and are connected with said two welding head halves 10 to displace them toward each other. Said drives 20 feature working stroke and force that allow in welding of two rail sections a simultaneous adjustment of track tension depending upon ambient temperature and rail length.
EFFECT: closure of welded sections and stabilised tension.
16 cl, 15 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to rail welding machine and can be used for welding separate rails, long rail sections and repair of tracks in the field. Two jar clamps are composed of two isolated double-arm levers fitted on common axle. Machine includes hydraulic cylinders for clamping and transfer of parts being welded. Two welding transformers are built in double-arm levers of one of said two jaw clamps. Current feed elements comprises rods and displacement and shrinkage, electric contact clamps and flexible jumpers. Said electric contact clamps are furnished with controlled drives. Top part of every said electric contact clamp has holes for guide rods to pass there through while its side surface has locking spring.
EFFECT: stable electric circuit and welding, high quality of welded joints.
FIELD: process engineering.
SUBSTANCE: invention relates to method and mill for production of welded I-beam. Proposed method allows the welding of four-flange seams by argon arc in one pass. Proposed mill comprises bed 1, hydraulically driven rolls 2 with reversible electric drive for setting and centring of beam wall and fitting the beam to welding start position, clamping rolls 3 to centre top flange relative to beam wall, welding heads 5, main hydraulic clamp 6 with roller, bridge 7, supports 8, 10 with hydraulic drives to mounting welding heads, inlet roll table 9, electrically driven propulsor 11 composed of pull roller with drive motor 12. Governor 14 is connected in main motor circuit to control pull roller shaft rpm, that is, the welding rate.
EFFECT: higher quality, longer life of beam drive, expanded range of products.
6 cl, 4 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to construction, particularly, to pile foundations laid in permafrost soils. Proposed method comprises cutting of the ends of pile elements. After cutting, pile elements are assembled. Then, four hexahedral reinforcing straps are welded to pile butt surface outer surfaces by angular weld seams over the entire perimetre. Welding zone is heated. Weld beads are laid for welding. Then, weld joint is cooled down. Thereafter, postwelding thermal treatment of weld seam is effected.
EFFECT: higher bearing capacity of welded pile.
2 dwg, 1 tbl, 1 ex
FIELD: process engineering.
SUBSTANCE: invention relates to multiarc welding of welded blanks for making car body parts by cold forging. First, current and rate of first arc welding are selected proceeding from penetration into the entire depth of blank and fusion isotherm on blank surface on welding side. Selected are the number of arc, current of every next arc and distance there between so make fusion isotherm width for every arc on blank surface at weld side complies with isotherm width on welding side of every previous arc while arc crater diameters in welding bath are smaller than welding bath fusion isotherms on the side of crystallisation front of welding bath fusion isotherm. First arc electrode is set 65-75° to welding direction while electrodes of the next arcs are set at 105-115° to said direction. Blanks are butt welded at water-cooled appliance in atmosphere of protective gases at constant current and with separate supply of the arcs.
EFFECT: invariable weld seam geometry, smaller area of melted zone of weld joint, hoint plastic structure.
FIELD: process engineering.
SUBSTANCE: invention relates to welding and may be used for welding of two pipes in laying of pipelines. Welding bug comprises welding torch 3 arranged to turn about first and second horizontal axes 21, 23 and to displace between working position whereat said torch is located at flute 19 and turned-off position whereat said torch 3 is spaced from said flute. Control lever 7 is connected with torch 3 to displace it between said positions and to turn about first axis 21. Torch 3 can turn in reverse direction about second axis 23. Both axes are mainly parallel with tangent to pipe cross-section at welding point.
EFFECT: compact design, higher quality of welding.
19 cl, 6 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to production of shaft for turbine and/or generator by welding and to shaft thus made. Shaft element 5 of one central part side confining its circular surface relative to rotational axis 2 is removed to produce at least one exposed cavity 11 in at least one cylinder 3 in the limits of left tube-shape rib 13. Two shaft elements 5 are located and aligned along rotational axis 2 to make hollow cavity 15. First tubular seam 17 is produced by arc welding into narrow clearance. Through hole 18 is made outside of one of two shaft elements opened into said hollow space 15. Quality of said first seam 17 is estimated from inside of said hollows space 15 during or after welding with the help of radiation receiver 19 or radiation source 19a inserted via through hole 18 in hollow space 15t.
EFFECT: direct control over welding.
14 cl, 2 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to pressure welding, particularly, to diffusion welding at low-intensity power effects and may be used for making thin-wall structures from OT4-1 titanium alloy. Proposed method comprises heating to welding temperature, jointing two work pieces for time sufficient for making a physical contact between surfaces to be jointed together. Heating at first stage is performed with application of welding pressure for development of 3D interaction. At second stage, heating is performed with application of welding pressure. At said first stage heating is performed in conversion temperature range α+β→β for time τw defined as follows: τw=k·p-n·exp(E/RT)·lnRa, where k is empirical factor describing kinetics of the development of physical contact area between surfaces to be jointed equal to 1.75·10-7 s, p is numerical magnitude of welding pressure, MPa, n is empirical factor describing material creepage equal to 1,2, E is activation energy, J/mol, R is gas constant, J/(K·mol), T is heating temperature, K, Ra is numerical value of surface roughness.
EFFECT: decreased accumulates strain in work pieces, power savings.
FIELD: process engineering.
SUBSTANCE: bar or tube rolling stand device comprises roll mount and roll and roll shaft, axial bearing fitted on roll one end for roll to run in roll mount. Note here that said radial bearing has, at least two rows, each provided with different-diameter races of inner and/or outer bearing rings.
EFFECT: possibility to take up higher loads, reduced production costs.
13 cl, 1 dwg