Method of producing variable cross-section thin-wall shells

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to production of thin-wall high-strength shells from steel tube billets. Tubes made from killed steel represent said billets. Forming is performed by rotary and/or press processing to produce curvilinear, transition and cylindrical sections with axial direction of deformation. First, machined are transition conical and curvilinear parts with wall thickness and ultimate strength increasing and diameter decreasing toward reduced end. Then, transition part with variable cross-section and cylindrical part with tapering wall sections are processed in opposite direction. Note here that transition part is formed with cylindrical fillet with inclination of smaller than inclination of transition part generatrix in initial machining. At the end of machining, annealing is performed to reduce strain at 340-360°C.

EFFECT: higher surface precision and quality.

10 cl, 8 dwg, 1 tbl, 2 ex

 

The invention relates to the field of metal forming, namely the manufacture of thin-walled shells of variable cross-section of steel billets methods of processing metals by pressure - rotating and pressing processing.

Thin-walled casing of variable cross-section used in the manufacture of pressure vessel housings of the cylinders, lanero, fire extinguishers, operating under internal pressure fillers, and, under external influences, is on fire, underwater works and other extreme conditions.

The most important problems in the manufacture of thin-walled shells of variable cross section, which represents an axisymmetric shell with conical or curved and cylindrical parts of different thickness, a high dimensional accuracy and a high rate of material usage, performance, and high mechanical properties at small thickness.

Feature of thin shells with variable cross-section is a thin wall cylindrical portion and a large and variable wall thickness of the curved part.

There are many methods of making such membranes processing of metals by pressure - rotary extractor and rotary swaging rotary handle, hood and crimping press processing.

In the book Century. Romanovskaja. Reference "cold pressing". L.: engineering, 1979, s in the Chapter "drawing of parts of a conical form, is, "a" and "b" describes how to extract the conical parts with cone angle from 10° to 30°.

The disadvantage of this method is the low utilization rate of the metal, because the original billet is a circle, and a large number of operations, which leads to high complexity manufacturing details.

Chapter 32 "Swage" this guide describes how crimping billets RIS, 2, which shows the crimping of tubular membranes with a cone angle α=20° and a banner with the angle α=40°. Stretching and crimping can be performed in one operation with a significant difference of diameters of cylindrical and objetos parts.

The disadvantages of these methods forging processing is the inability to obtain the wall thickness of varying thickness objetos and cylindrical parts.

In the book Niemoeller. "Rotary extractor shell parts on the machines. M: mechanical engineering, 1983, s, 111 in Chapter 7. Selection and calculation of the blanks " on fig.6.11 shows the method of manufacturing a tapered and curved shells of sheet and forged products by rotational exhaust projection for one or two transitions.

The disadvantages of this method include low utilization rate of the metal and vozmozhnosti receiving cylindrical part of the shell.

In the book Weglarowicz. "Running in the manufacture of metal". M.: Mashinostroenie, 1973, p.7÷22, Chapter 2. The rolling cones on the mandrel provides various methods of obtaining shell of tubular and flat workpieces, without mandrel and the mandrel, the tool friction rollers, which receive a cylindrical shell with a tapered and curved profiles necks with variable wall thickness.

The main disadvantage of these methods applied to the problem of obtaining thin shells with variable cross-section, is the lack of solutions for thinning mating cylindrical and transient parts of the shell.

The closest to the technical essence and the achieved technical result is "a Method of manufacturing hollow articles" A.S. No. 719750, CL 21D 22/06, BI No. 9, 1980, in which use tubular billet, forging processing, first carry out the crimping on a cone, then crimping and hot landing thickening at the end objetos part, then the distribution of the cylindrical part and, at the end of processing, the hood with thinning of the cylindrical part, when the crimp angle of taper set (see sheet 4) within 7÷15°, wall thickness to withstand increasing towards objimage end, hand perform with a degree of deformation of 0.7÷1.3% of the degree of swaging.

This method adopted by the authors for protot the p.

As can be seen from this technical solution, the process of extrusion processing carried out four operations, first perform the crimping of the conical part, and then crimping curved part and a hot landing thickening at the crimped end, then perform the hand and the hood with the thinning of the cylindrical part.

For reasons that impede the achievement of the technical result when using the known method adopted by the authors for the prototype, is the uneven deformation in the transition zone curvilinear objetos part cylindrical, which leads to the formation of tightened metal, cracks and separation of the cylindrical part when the hood with thinning.

In addition, the prototype shows the formula of change of the wall thickness at the crimping of a cone with an angle of inclination of the generatrix 7÷15°, which is not applicable when the crimping pieces with a curvilinear generatrix with a large range of manufacturing buildings for various purposes.

In the prototype also does not reflect the factors influencing performance of buildings: change in mechanical properties along a curved part, the direction of deformation, the ratio of degrees of deformation at the time of forming curved and cylindrical portions, the temperature of the finishing heat treatment, and the use of rotary processing affecting accuracy the ü and quality of processing.

Thus, the objective of this technical solution adopted by the applicants for the prototype was to create a method of manufacturing hollow articles forging processing - conical crimping portion, the crimping hot and disembarking internal thickening and then the distribution and extraction of the cylindrical part to improve the utilization of metal.

Common features offered by the authors is the use of a tubular workpiece, the crimping of the one part and another hood.

Unlike the prototype proposed by the authors in the method of manufacturing thin-walled shells of variable cross-section, as blanks used steel pipe calm brand with a tensile strength of 32÷65 (kgf/mm2), forming perform rotation and, or press processing of the workpiece with the formation of a curved transition and cylindrical parts with the axial direction of deformation of the first handle transitional conical and curved parts with wall thickness and tensile strength of the material increasing and decreasing diameter in the direction of obamamama end, then in the opposite direction of the transition piece with variable wall thickness and cylindrical with thinning of the wall, when a transitional portion is formed with a cylindrical shoulder and a conical section with an angle N. the clone forming a smaller 1.5÷2.5 times the angle of inclination of the generatrix of the transition portion at its initial processing and at the end of processing to perform the annealing reduces the voltage at a temperature of 340÷360°C.

In particular cases, that is, specific forms of implementation, the invention is characterized by the following features:

- crimping curved parts perform wall thickness at the crimped end is 1,1÷1.5 wall thickness of the workpiece;

- crimping transition and curved parts perform with the tensile strength of the material in the direction of decreasing diameter toward the end face of changed dependencies:

where σB(kgf/mm2- the current value of the tensile strength,

σB Ref(kgf/mm2) - the original value of the tensile strength,

ε (%) - the degree of deformation of the crimp,

α° - current value of the cone angle curved portion;

a cylindrical band of the transition portion of the workpiece when the hood is formed with a length not exceeding the wall thickness of the workpiece;

- transitional part billet hood with thinning form the wall thickness of the workpiece conical section, decreasing in the direction from the curved part to cylindrical;

- forming blanks exercise first rotary crimping transition and curved parts, and then extraction with thinning transition and cylindrical parts forging machining;

the forming of the workpiece presses perform the second processing - first crimping curved, then the distribution of transition, cylindrical and curved parts, and then rotating hood with wall reduction transition and cylindrical parts;

- the degree of deformation of the cylindrical portion of the workpiece when the distribution is equal to the degree of deformation of the diameter change when the hood with thinning of the wall of the same part;

- crimping curved and distribution of cylindrical and transient parts performing press processing in one move, press;

the degree of deformation during crimping curved part is 0.7÷0,9 degree of deformation in the hood with the thinning of the cylindrical part;

It allows to make a conclusion about the causal connection between the set of essential features of the proposed technical solution and achievable technical result.

These characteristics, distinctive features of the prototype and to which the requested amount of legal protection, in all cases sufficient.

The task of the invention is to enable the production of thin-walled shells of variable cross-section rotating and pressing processing separately and their combination with high accuracy geometric shape and surface quality, with metal saving and productivity with high stable is ivoti process variation, as well as increasing strength and reliability.

This technical result in the implementation of the invention is achieved in that in the known method, including crimping curved part of the billet and the hood another feature is that as the blanks used steel pipe calm brand with a tensile strength of 32÷65 kgf/mm2, forming perform rotation and, or press processing of the workpiece with the formation of a curved transition and cylindrical parts with the axial direction of deformation of the first handle transitional conical and curved parts with wall thickness and tensile strength of the material increasing and decreasing diameter in the direction of obamamama end, then in the opposite direction to perform the extraction of the transition part with variable wall thickness and cylindrical with thinning of the wall, when a transitional portion is formed with a cylindrical shoulder and a conical section with an angle of inclination of the generatrix of the lower 1.5÷2.5 times the angle of inclination of the generatrix of the transition part in the initial treatment and at the end of processing perform annealing, reducing the voltage at a temperature of 340÷360°C.

A new set of operations, and the existence of linkages between them allow, in particular, due to:

- use quality is TBE billet steel pipes calm brand to improve the performance properties of the section: to increase the impact strength of the material at sub-zero temperatures to prevent formation of cracks in the case, for example when falling in freezing temperatures, which can lead to cracks and then to emergency situations;

- use as a billet pipe with a tensile strength of 32÷65 (kgf/mm2- to extend the range of the used pipes, that is to use hot rolled pipe with a tensile strength of 32 kgf/mm2and cold-rolled pipe with a tensile strength of 65 kgf/mm2;

- forming of workpieces rotating and pressing treatment to expand the technological capabilities of production in view of the fact that the combination of these methods gives the effect of increasing the performance, accuracy and quality of the processed surface, the use of methods and rotary forging processing separately efficient since the formation of the most difficult transitional parts of the billet where there are bumps and tightening the metal with the formation of cracks and breaks, perform as well as rotation and extrusion processing with the same geometrical dimensions;

education curved transition and cylindrical parts to improve the dimensional accuracy and quality of the workpiece as a result of th is forming between curved and cylindrical parts of the transition part is used to eliminate the corrugations, laces and cracks in this zone of transition from one form of surface to another.

education curved transition and cylindrical parts with the axial direction of the deformation is to increase the mechanical properties of metal buildings mainly in the axial direction (tensile strength, hardness, yield strength), as in the axial direction of deformation in longitudinal section of harvesting grain microstructure of metal - texture deformation (see the book Apoleia. "Physical metallurgy". M., 1951, s, 131) is an ellipse, the major axis oriented in the direction of the deformation, i.e. in the direction of axial movement of the deforming tool, rollers while rotating the crimping and rotating the hood, punch with the workpiece in the matrix during extrusion processing; improvement of mechanical properties of the metal in the axial direction are confirmed by the results of the mechanical tests tensile longitudinal and transverse samples; the physical meaning of the phenomenon of primary hardening of the metal in the axial direction of deformation can be represented in the form of movement - the flow of incompressible fluid in the form of drops - grains of the polycrystal, which under the action of the deforming tool in the direction of the deformation, i.e. in the direction of flow of the liquid metal into the drops are spherical form ellipsoids targeting the new major axis along the lines of a liquid-metal i.e. the direction of deformation and the grain orientation of the ellipsoids do not depend on the direction of flow of the liquid metal, the axis of the ellipsoids-grains are elongated along the lines of power metal in one and in the other direction of metal flow; the number of deformed grains of the metal per unit cross-sectional area in the axial direction of the deformation (1 mm2much higher than in the transverse direction, as well as the largest axes of the grains have the greatest strength in the direction of the deformation (see the book Apoleia "physical Metallurgy". M., 1951, s), and mechanical properties of the metal billet in the axial direction of deformation is much higher than in other directions, so the predominant hardening of the metal in the axial direction increases the operational properties of buildings with small wall thickness of the cylindrical part while reducing weight; the results of the tests of enclosures cyclic internal pressure showed that the predominant hardening of the metal in the axial direction (generatrix) increases cyclic strength of the buildings, the results of the tests of the hull to the final destruction of the internal and external pressures showed that the cracks in the destruction have shatterproof nature, are arranged along the cylindrical portion and terminating in crinoline the Noah part, what if an emergency prevents a user (firefighters, divers and rescue workers from injuries;

it should also be noted that the texture deformation, which determines the predominant largest mechanical properties in the axial direction of the generatrix of the workpiece and identified on longitudinal samples during tensile tests, depends on the degree of deformation and the final heat treatment of the buildings, so to a large degree of deformation of the cylindrical portion of the workpiece mechanical properties of metal this part is higher than a curved transitional portion, and the distribution of mechanical properties in the axial and transverse direction is not changed; if the temperature is low the finish heat treatment (low temperature annealing) texture deformation and, consequently, the distribution of mechanical properties in all areas and directions (longitudinal and transverse) does not change;

processing first transition conical and curved part towards Aliyeva end, then in the opposite direction of the transition part with variable wall thickness and cylindrical wall reduction is to improve the dimensional accuracy and quality of the workpiece, as this provides dual processing transition pieces in different directions with the thickness of the article is NCI changes smoothly from the curved to the cylindrical part, that eliminates the formation of corrugations in the transition part, according to the applicants when such a sequence of operations in the transition area creates stress state with a radial compressive and tensile stresses, preventing the flow of metal from the mandrel in the area of transition to the cylindrical part and the flow of metal to the frame in the transition zone to the curved portion; the mechanism of this effect is the following:

a) when processing a transition portion toward Aliyeva the end zones of the curve forming the transition from the cylinder to the cone formed radial tensile stresses under the action of which the metal tends to flow from the mandrel, the transition from cone to the curved part arise radial compressive stresses under the action of which the metal is committed to the mandrel, in the first case there corrugations of the other folds;

b) during processing of the transition portion in the opposite direction radial stress change its sign to the opposite zones of transition from the curved part of the transition to and from transition to cylindrical, which eliminates the formation of bumps and folds;

- processing of curvilinear side wall thickness and tensile strength of the material increasing and decreasing diameter in the direction of obamamama end - to increase the exploitation the ionic properties of buildings - durability, reliability, service life and storage, as well as cyclic strength in the joint increase in wall thickness and mechanical properties of the hull towards Aliyeva end;

- formation of the transition portion with a cylindrical shoulder and a tapered section when processing in the opposite direction - to improve the accuracy and quality of the workpiece, as in this case, the cylindrical band is stabilizing in the result of reducing the unevenness of deformation when passing through centers of deformation from deforming tool rollers or matrix of transition zones curved outer and inner surfaces of the cylindrical - external and internal; the physical meaning of this is to offset zones of inflection along the inner and outer surface that eliminates the possibility of formation tightened, wrinkles and cracks in these areas.

- the formation of the conical section of the transition portion of the workpiece in the opposite direction with an angle of inclination of the generatrix, less 1.5÷2.5 times the angle of the transition portion at its initial forming, to improve the stability of the formation process resulting in a gradual dvuhprohodnoe processing of this part, in the beginning a transitional portion having a large angle when it is processed in the direction of crimping is the PTO end, then in the opposite direction with a smaller angle; the angle of inclination of the generatrix less than 1.5÷2.5 times the tilt angle when the initial treatment is best determined experimentally, for values beyond these limits in one direction or another, there are buckles or laces and cracks with a margin of the cylindrical part; the applicants believe that the positive effect of this treatment, the transition part is also changing the nature of the stress state of the metal during processing in the opposite direction, in the zone of inflection forming arise radial voltage, opposite in sign to the voltage in the initial processing of the transition part towards Aliyeva end, which prevents the bumps, tightened and cracks;

- run at the end of the annealing treatment of reducing the voltage at a temperature of 340÷360°C - remove the internal stresses in the metal casing while maintaining high mechanical properties (tensile strength). Temperature 340÷360°C below 0.4 TPL=0,4×1350°=540°C, therefore recrystallization (grain growth with a reduction of tensile strength) does not occur (see the book Angaleena. "Physical metallurgy". M., 1951, Fig, p.131); in the low-temperature annealing at this temperature is maintained texture deformation i.e. preserves the direction of time and the minimum level of deformed grains of the microstructure of the metal, therefore, the mechanical properties in different areas and directions (longitudinal and transverse) are stored.

The features characterizing the invention in specific forms of execution, allow, in particular, due to:

- crimping curved part of the wall thickness at the crimped end is 1,1÷1.5 wall thickness of the workpiece, to increase the stability of the processes of deformation of the workpiece as rotary swaging and crimping press processing, because the process of crimping a characteristic increase in wall thickness in the direction objimage end, i.e. in the direction of decreasing diameter, and this process is most stable when the wall thickness of the compressed end in the range from 1.1÷1.5 wall thickness of the workpiece at the beginning of crimping; when the thickness of the blank over 1.5 wall thickness of the workpiece increases the number of transitions, and at less than 1.1 arise bumps and cracks in compressed end restrictions radial metal flow;

- perform crimping curved parts with a tensile strength of the material in the direction of obamamama face changed dependencies:

where σIn(kgf/mm2- the current value of the tensile strength,

σEx(kgf/mm2) - the original value of the tensile strength,

ε (%) - the degree of deformation of the crimp,

α° - current value of the cone angle Cree is ainamoi part;

to ensure a smooth increase of the tensile strength from the beginning of the curved part to obamamama end depending on the degree of deformation and angle of inclination of the generatrix, that is, the angle of the taper curved surface, this formula was determined experimentally in the process of working out the method of manufacturing buildings and in conjunction with the wall thickness gradually increasing to obamamama end, ensures high operational reliability of the body, strength, durability and storage, cyclic strength;

the formation of the transition portion of the billet hood with a cylindrical belt length not exceeding the wall thickness of the workpiece, to increase the stability of the forming process, since the length of the belt over the wall thickness increases the weight of the body, and when the length of the belt is too small, close to zero, reduces the stability of the process variation due to proximity to each other breaklines forming on the inner and outer surface, which increases the non-uniformity of deformation in the coupling zone curvilinear and transition part and increases the likelihood of homeopathy;

- formation of the transition portion of the billet hood with thinning wall thickness of the conical section, decreasing in the direction from the curved part to cylindrical, to increase the stability about the ECCA formation, due to the fact that the wall thickness of the tapered section gradually decreases from the cylindrical section in a direction from the curved to the cylindrical part, which provides a smooth increase of the strain along the lines of power metal (the generatrix of the conical section of the mandrel) and to eliminate the formation of bumps, cracks and separation of the cylindrical part from the curvilinear;

- forming of the workpiece first rotary crimping transition and curved parts, and then extraction with thinning transition and cylindrical parts forging processing is to expand the technological capabilities of production buildings and increase productivity, accuracy and surface finish quality, reduced the probability of occurrence of waviness, roughness, and other minor defects;

- forming of the workpiece forging processing is first crimped curved, then the distribution of transition, cylindrical and curved parts, and then rotating hood with wall reduction transition and cylindrical parts to expand the technological capabilities of production buildings, increase productivity, accuracy and quality of the processed surface as a combination of pressing and rotating the handle gives a new quality of the proposed method, due to the fact that extrusion processing - crimping, mA is a, the hood is made with high velocity deformation, which increases the purity of the surface, and rotation processing - rotary extractor, rotary swaging is performed with local centers of deformation at a lower rate that they can handle the transition of the mating zone, having bends forming with a gradual increase in deformation along the current lines of metal on the mandrel, and the result is to eliminate the formation of corrugations and laces, as well as cracks in the transient part of the workpiece; thus forging processing receive high surface purity, rotary processing - high accuracy geometric shapes, and their combination in varying sequence and gives high accuracy of geometric dimensions and high quality surface finish;

- hand cylindrical portion of the workpiece with the degree of deformation is equal to the degree of deformation of the diameter change when the hood with thinning of the wall of this part of the forging processing, to ensure the sustainability of the process of forming the cylindrical part, because the distribution in the workpiece implemented compressive radial stress, which in the subsequent extraction with thinning prevent the increase of the outer diameter of the cylindrical part after passing the billet through a die, that is, compensate for radial indeed, ewusie voltage and the increase in the diameter of the cylindrical part; the equality of the degrees of deformation of the diameter change in the distribution and extract subject to obtaining the final dimensions of the inner and outer surface of the cylindrical part without additional machining, which increases the utilization of metal;

- crimping curved part with a degree of deformation 0.7÷0,9 degree of deformation in the hood with the thinning of the cylindrical part, is to improve the performance of the process of forming the workpiece as when rotating and pressing treatments, and their combinations, this ratio is optimally determined by experimental testing, when the degree of deformation of the crimping over of 0.9 degree of deformation in the hood with thinning increases the number of crimping operations, and at less than 0.7 will need additional increase in the number of extraction operations, which increases the complexity of manufacturing buildings;

- perform crimping curved and cylindrical distribution and transition parts forging processing for one stroke of the press is to improve the efficiency of case production by combining two operations into one.

The features that distinguish the proposed solution from the prototype, not identified in other technical solutions and not known from the prior art in the process of patent research, which allows the to conclude according to the invention, the criterion of "novelty".

Examining the prior art during the patent search all kinds of information available in countries of the former USSR and foreign countries, found that the proposed technical solution is not obvious from the known prior art, therefore, it is possible to conclude that the criterion of "inventive step".

The invention consists in that in the method of manufacturing thin-walled shells of variable cross-section as blanks used steel pipe calm brand with a tensile strength of 32÷65 kgf/mm2, forming perform rotation and, or press processing of the workpiece with the formation of a curved transition and cylindrical parts, with the axial direction of deformation of the first handle transitional conical and curved parts with wall thickness and tensile strength of the material increasing and the diameter decreases in the direction to obamamama end, then in the opposite direction - transition with variable wall thickness and cylindrical with thinning of the wall, when a transitional portion is formed with a cylindrical shoulder and a conical section with an angle of inclination of the generatrix, less 1.5÷2.5 times the angle of inclination of the generatrix of the transition portion at its initial processing, and the end of the process performing annealing, menshawi the voltage at a temperature of 340÷360°C.

The invention is illustrated by drawings, where figure 1 shows the process of rotary swaging transition and curved parts, figure 2 - process rotary hood with wall reduction transition and cylindrical parts, figure 3 - rotary and rotary crimping hood with thinning transition and cylindrical parts in the enlarged view, figure 4 - crimping curved part of the forging processing, figure 5 - distribution of cylindrical, curved and transition parts forging processing, 6 - hood with thinning transition and cylindrical parts forging processing, 7 - crimping, distribution and hood with thinning transition and cylindrical parts forging processing in a larger view, Fig - crimping curved and the distribution of transition and cylindrical parts forging processing.

Figure 1 depicts the workpiece 1 in the initial state with diameter Dzag(mm)thickness tzag(mm), the workpiece 2 after rotation of the crimping, the mandrel 3, deforming rollers 4 at the beginning and end crimping, the direction of axial F1(mm/min), the direction of rotation of the workpiece with a mandrel S1(min-1), the cylindrical portion of the workpiece length LC(mm), the transition portion length L1(mm) angle of inclination of the generatrix of β° and a curved portion with a length L0(mm) with cone angle α°, the thickness t 0(mm) at the beginning and t1(mm) at the end of crimping, with the diameter of the first crimping D0(mm) and at the end of the crimping d (mm)- (mm) length start processing from objimage end to the line of incision.

Figure 2 shows the workpiece 2 in the initial state, obtained by a rotary swaging, the workpiece 5 after rotating hood with thinning of the wall with the length of the cylindrical part of the LW2(mm), wall thickness of the cylindrical part of tC(mm)length of the curved part of the L0(mm)thickness of the curved part at the beginning of t0(mm)thickness of the curved part at the end of t1(mm)diameter curved part at the beginning of the D0(mm) and d (mm), length of the transition part of the L2(mm)length of the cylindrical band transition of LC(mm)length of the conical section of the transition part of the LTo(mm)angle of inclination of the generatrix of the conical section of the transition portion γ°, the direction of axial F2(mm/min), the direction of rotation of the workpiece S2(min-1), the rollers 4, the mandrel 6.

Figure 3 of the workpiece 2 in the initial state after rotating crimping with the original wall thickness tzagwith wall thickness at the beginning of the curved part of t0(mm), diameter at the beginning of the curved part of the D0(mm)length of the transition part of the L1(mm)angle of inclination of the generatrix of the PE echidnas part β° (AA 1B1B), the workpiece 5 after rotating hood with thinning wall thickness at the beginning of the rotary hood t0(mm)equal to the wall thickness at the beginning of the rotary crimping t0(mm), wall thickness of the cylindrical part of tC(mm), with a transition part (AA1DD1BB1CC1), with the length of the cylindrical band transition of Lp(mm)length of the conical section of the transition part of the LTo(mm)length of the transition part of the L2(mm)angle of inclination of the generatrix of the conical section of the transition portion γ° (DD1CC1), the mandrel 6, deforming rollers 4 at the beginning of the rotary exhaust transition and the process of rotational extrusion of the cylindrical part.

Figure 4 depicts the workpiece 1 in the initial state with wall thickness tzag(mm) length Lzag(mm)workpiece 7 after crimping of the wall thickness at the beginning of the curved part of t0(mm) and at the end of t1(mm), diameter at the beginning of the curved part of the D0(mm) and at the end of the d1(mm)length of the curved part of the L0(mm) and cylindrical part of the LC(mm), the punch 8 with the direction of axial movement F1(mm/min), the matrix 9, the guide sleeve 10 and the ejector 11.

Figure 5 shows a: preparation of 7 after crimping in the initial state with a wall thickness of 6 the beginning of the curved part of t0(mm) and is emetrol D 0(mm)wall thickness at the end of the curved part of t1(mm) and a diameter of d1(mm)length of the cylindrical part of the LC(mm)length of the curved part of the L0(mm), the workpiece 2 after the deal with the length of the curved part of the L0(mm), diameter at the beginning of the D0(mm) and at the end of the curved part of the d2(mm) wall thickness at the beginning of t0(mm) and at the end of t1(mm) curved part, with the length of the transition part of the L1(mm)length of the cylindrical part of the LC1(mm)angle of inclination of the generatrix of the transition part β°, the plug 12 with the direction of axial movement F1(mm/min), the matrix 13, the puller 14.

Figure 6 depicts the workpiece 1 in the initial state at the start of the hoods with thinning, harvesting 5 in the process of drawing, the punch 15 in two positions : at the beginning of the drawing and in the process of extraction, matrix hood 16, the stripper 17, the direction of axial movement of the punch with the workpiece in the process of drawing F2(mm/min), L1(mm) - length of the transition area before the hood or after the distribution (figure 5), L2(mm) - length of the transition portion after extraction with thinning, Lp(mm) - length of the cylindrical band transition after the drawing, LTo(mm) is the length of the conical transition area after the extraction, tzag(mm) - wall thickness of the cylindrical part of the front hood, tsub> C(mm) - wall thickness of the cylindrical part after extraction with thinning, ∆ D (mm) is the change in internal diameter after the deal and outer diameter after drawing with thinning, β° - the angle of the generatrix of the transition part after the deal and before extraction, γ° is the angle of inclination of the generatrix of the conical transition area after the extraction. D0(mm) is the diameter of the beginning of the curved part, t0(mm) wall thickness the beginning of the curved part.

Figure 7 shows the transition portion of the workpiece in an enlarged scale in the beginning and in the process of drawing with the thinning with the workpiece 2 in front and the workpiece 3 in the process of drawing with thinning, the punch 15 and the sensor 16 in two positions at the beginning and in the process of drawing with thinning, the transition portion (AA1B1B) after distributions and before extraction with thinning, L1(mm) - length of the transition portion after the deal before extraction with thinning, L2(mm) - length of the transition portion after extraction with thinning, L2=Lp+LToi.e. the length of the transition portion after extraction with thinning is the sum of the lengths of the cylindrical belt and the conical section. The transition portion after extraction with thinning - AA1D1C1CD. The angles β° γ° - angles forming a transition portion before and after extraction, tzag(mm) and tC(mm) - thickness of the cylindrical wall is part of the before and after extraction, D0(mm) is the diameter at the beginning of the curved part, t0(mm) wall thickness at the beginning of the curved part.

On Fig depicts the process of crimping and dealt with the position of the workpieces 1 and 2 to the beginning of the process and in its final stage, which also shows the punch 18, the matrix 19, extractor 14, the ejector 11, the direction of axial movement of the punch and workpiece - F1(mm/min), Lzag(mm) and tzag(mm) length and thickness of the workpiece prior to crimping and distribution, t0(mm) and t1(mm) wall thickness at the beginning and end of the curved part, d (mm) outer diameter objetos harvest at the end of a curved part, L1(mm) - length of the transition part,(mm) - length objetos curved part, β° - the angle of the generatrix of the transition part.

The above method of manufacturing buildings is as follows.

The source of the workpiece 1 (figure 1) is made of a steel pipe calm steel, hot-rolled or cold-rolled, with a tensile strength of 32÷65 kgf/mm2by cutting on the workpiece and machining.

For housings of rotary methods of processing the workpiece 1 is installed on the mandrel 3, fixed on the spindle pressure-Raskatov machine is fixed on the mandrel clamping device and carry out a rotary crimping deforming rollers is 4 from the cylindrical part of the billet length L C(mm) distancefrom objimage end towards Aliyeva end, first compresses a transitional tapered portion length L1(mm) angle of inclination of the generatrix of β and wall thickness t0(mm), and then compresses the curved portion of length L0(mm) wall thickness, increasing from t0(mm) at the beginning of the curved part, to t1(mm) at the end of the curved portion, with the diameter decreasing from the diameter D0(mm) at the beginning of the diameter d (mm) at the end of the curved portion, with the angle of the tangent to the curved surface of α°, also increasing from the beginning of treatment to the end of a curved surface, with tensile strength, increasing in the same direction.

The axial direction of the feed rollers F1(mm/min) to obamamama the end.

Then in the opposite direction of the crimping perform rotary hood with wall reduction transition and cylindrical parts (2, 3).

First handle transition portion of length L2(mm) stilisticheskim belt length Lp(mm)thickness t0(mm) and a conical section with a length LTo(mm) wall thickness decreasing in the direction from the curved part to the cylindrical part of t0(mm) to tC(mm).

Next, perform a rotational stretching of the cylindrical part of the wall reduction with wall thickness t C(mm) with the degree of deformation εCwith a length of cylindrical part of the LW2(mm).

The axial direction of the feed rollers F2(mm/min) when rotating the hood (figure 2) opposite to the direction of feed rollers while rotating the crimping F1(figure 1).

For housings of methods of extrusion processing and combined press-rotary and rotary press (figure 4÷8) the sequence of operations is as follows.

First press treatment (figure 4) forming a curved portion by the crimping of the workpiece 1 by the punch 8 in the matrix 9. The workpiece 1 in the initial position set in the guide 10. the workpiece in the initial position has a size of tzag(mm) wall thickness and Lzag(mm) - length of the workpiece. After crimping of the workpiece 7 is: the length of the curved part of the L0(mm)wall thickness at the beginning of the curved part of t0(mm)wall thickness at the end of the curved part at the crimped end of the t1(mm), the length of the cylindrical part of the LC(mm), diameter curved part at the start of D0(mm) and end at the crimped end of the d1(mm).

Then the workpiece 7 (figure 5) distribute the punch 12 in the matrix 13 with the formation of the cylindrical section of length LC1(mm), the transition part of the L1(mm) angle of inclination of the generatrix - β°, curved side length L0(mm) wall thickness t0(mm) is the Achal, t1(mm) - at the end of the curved part at the crimped end.

The thickness of the workpiece tzag(mm) and t1(mm) are slightly changed and the sizes of the D0(mm) and t0(mm) at the beginning of the curved part is not changed.

The internal profile of the curved part of the final without additional machining, the diameter d1(mm) increases to d2(mm)wall thickness t1(mm) practically does not change.

At flybacks press the workpiece 2 is removed from the punch 12 puller 14.

Next, the workpiece 2 (6) punch 15 is subjected to extraction with thinning press processing in the matrix 16 with thickness tzag(mm) to the thickness tC(mm), thus beginning a transitional piece with a size varying with L1(mm) up to L2(mm), with β° γ°, with t0(mm) up to tC(mm) length LTo(mm), and with a cylindrical belt length LTo(mm) wall thickness t0(mm).

The diameter at the beginning of the curved part of the D0(mm) and wall thickness of the beginning of the curved part of t0(mm) are not changed.

After drawing back when the workpiece 5 is removed from the punch 15 the stripper 17.

Scheme of the process of forming the transition part (3, 7) when rotating, pressing, when combined press-rotary and rotary-p is escoval treatments, is a first crimping or distribution part of ABB1A1length L1with the angle of inclination of the generatrix of β° in the direction of obamamama the end and then the hood with thinning the same part in the opposite direction with the formation of a cylindrical band ADD1A1length Lp(mm) and tapered section DCC1D1length LTo(mm) inclination of the generatrix γ° and a total length L2(mm).

Combined extrusion-rotation treatment (figure 4, 5, 8 and 2) and rotary press (figure 1 and 6) treatments receive a housing with a curved transition and cylindrical parts on the same technological scheme: 1) in the process direction to obamamama end get first curvilinear and transitional parts; 2) opposite the process direction from the curved portion to the cylindrical get the adapter and the cylindrical part.

Thus when any of the listed processing transient part (3, 7) are obtained with the same geometrical dimensions and the same sequence of operations forming the cylindrical portion of the receive (2, 6) with the same size and in the same sequence, the curvilinear portion of the gain or distribution (figure 5) or clamped (figure 1, figure 4, Fig) also with the same size and in the same pic is egovernance.

Additionally, you may receive the curved part with the same size of the outer surface of the crimp (figure 4) press processing, and the cylindrical part mechanical turning on the inner surface.

Combined surgery of the hand and crimping (Fig) perform one stroke of the press. The workpiece 1 with a length Lzag(mm) and thickness tzag(mm) installed in the guide part of the matrix 19 and the punch 18 performs the distribution of the cylindrical section of length LC(mm), a transition portion with a length L1(mm) and the crimping curved portion length L0(mm)diameter D0(mm) at the beginning and d (mm) at the end of the curved portion, the wall thickness t0(mm) at the beginning and t1(mm) at the end of the curved part.

At flybacks press the workpiece is removed by the stripper 14 with the plug 18 or the ejector 11 of the matrix 19.

In the final stage of the process performing annealing at a temperature of 340÷360°C in an electric furnace with the shutter speed when the temperature of the metal 1,0÷2 hours.

Example 1.

Preparation of hot-rolled tubes ⌀133×14 steel 10 calm the brand with the original mechanical properties - tensile strength 32÷38 kgf/mm2after cutting into blanks, calibration of the inner surface is subjected to recrystallization annealing at a temperature of 630÷680°C, mechanical (turning) processing n the inner and outer surface.

Then round billet with a diameter of Dzag=130 mm with wall thickness tC=8 mm and length LC=550 mm mounted on the mandrel, mounted in the spindle pressure-Raskatov machine, fix one of the ends of the clamping device, and is subjected to its rotary crimping (Fig 1) in the direction of obamamama end. Beginning processing of the distance from the end to the line of incisionis determined from the equality of the volumes of the finished curved part and the processed portion of the workpiece.

The direction of the crimping F1(mm/min) from start of treatment to obamamama end (clamped end) is the axial direction of the rollers.

In the process of rotary swaging first form a conical transitional portion of length L1=30 mm with an angle of inclination of the generatrix β=4°, then a curved portion with a taper (double angle tangent to the curved surface) α° 4° at the beginning of the curved surface up to 20° from the crimped end at the end of a curved surface, a length L0=227,2 mm in diameter at the beginning of the curved part of the D0=121 mm, and at the end of the curved part of the d=76 mm, wall thickness at the beginning of t0=6 mm and at the end of the curved part at the crimped end of t=8 mm

The degree of deformation of the crimping increases from 0% to ε0% by the end of the curved part:

The crimping is carried out with a tensile strength of the material, increasing to obamamama end. At the beginning of the crimping at the time of the touch rollers billet tensile strength σEx=35 kgf/mm2and increases towards the end of the curved part on the formula:

where ε% degree of deformation of the crimp,

Dtech- the current value of the diameter,

α° is the angle of taper, the current value,

σex(kgf/mm2- the tensile strength in the initial state.

Values of tensile strength in the direction of the compressed end at distances from the beginning of the crimping 1 mm, 30 mm, 144 mm, 257,2 mm are given in table No. 1.

Table No. 1.
№ p/pLengthα°Dzag(mm)Dtech(mm)ε%σin(kgf/mm2)
10~11300035
218 130of 128.61,0837,7
33081301216,952,3
414410130111,614,1563,8
5257201307641,574,9

Analysis of the values of tensile strength depending on the length, taper angle and the degree of deformation (table 1) shows that the tensile strength of the material in the direction of the compressed end gradually increases to a maximum value of the compressed end in the axial direction (longitudinal sample) - (74,9 kgf/mm2) using the above formula, which corresponds to the proposed claims and the requirements of technical documentation.

These results are confirmed by the results of the mechanical tests of samples cut from the zone adjacent to the compressed end.

Thus, Uwe is ikenie tensile strength simultaneously with increased wall thickness to obamamama end face in the process of forming - crimping increases the operational reliability of buildings, durability, service life, shelf life and cyclic strength.

Then perform rotary hood with wall reduction transition and cylindrical parts in the opposite direction (figure 2) deforming rollers from the curved portion, with the curved part remains unchanged.

A transitional part of the gain length L1=71 mm with a cylindrical section of length Lp=7.8 mm (less than tzag=8 mm), which corresponds to the formula of the invention (Lp<tzagin the claims), and wall thickness t0=6 mm, with conical segment with a length LTo=63 mm and an angle of inclination of the generatrix γ=2°.

The degree of deformation of the transition part (2, 3) increases in the length L1=71 mm fromin cross-section A-A1(3) totensile strength (longitudinal sample) increases from 60 kg/mm2in the beginning of the transition section 80 kg/mm2at the end of this section in the cross section C-C1(figure 3) and remains unchanged throughout the cylindrical section.

Values of tensile strength in the transverse samples at the beginning and end of the curve and transition areas, as well as a cylindrical section at 10-15% less than the values for the longitudinal samples.

The cylindrical portion of the gain length is e less L C=619 mm, with a wall thickness of LC=4 mm

The degree of deformation when rotating the cylindrical hood portion at thinning the walls with t0=8,0 mm to 4 mm:

The angle of inclination of the generatrix at the hood of the transition part (γ=2°) 2.0 times less than the angle of inclination of the generatrix of the transition part swaging (β=4°), which corresponds to the formula of the invention.

The ratio of the degrees of deformation of the crimping and hoods ask the following. The degree of deformation during crimping curved part (ε0=41,5%) is 0.83 degree of deformation in the hood (εC=50%) of the cylindrical part, which corresponds to the formula of the invention.

At the end of processing to perform annealing, reducing the voltage at a temperature of 340÷360°C in an electric oven aged at this temperature for 1÷2 hours, then cooling in air to remove the internal stresses and save the texture deformation and mechanical properties of both the magnitude and the nature of the distribution on sites and in longitudinal and transverse direction.

When combined rotary press (1, 6) and press the rotary (figure 4, figure 5, Fig, 2) treatments rotary swaging and rotary extractor carry out the same as in the above example 1.

Example 2.

Preparation of cold-rolled pipes ⌀122×6 steel 10 great brand with original Predela the strength of the material σ in=60÷65 kgf/mm2after cutting the pipes into pieces and recrystallization annealing (at a temperature of 620÷650°C) one part of the workpiece lengthbillet with a diameter of 122 mm, a length LC=630 mm is installed in the guide matrix annealed part down and expose her to the crimping and distribution (Fig) to obtain the curved part at the beginning of the D0=121 mm, and at the end of the compressed end d=74,5 mm diameter of the inner surface 112,5 mm, with wall thickness tC=6 mm, t0=6 mm, t1=6,6 mm, L1=30 mm, β=4°.

Next, the workpiece is subjected to recrystallization annealing of the cylindrical part at a temperature of 620÷650°C and the hood with thinning (6) to obtain the same geometrical dimensions of the transition and the cylindrical parts and the same mechanical properties (see example 1).

At the end of processing to perform annealing, reducing the voltage at a temperature of 340÷360°C, which is also consistent with the claims.

At distribution (figure 5, Fig) and the hood of the cylindrical part (6) the degree of deformation of the inner diameter at distribution ∆ D (mm) is equal to the degree of deformation of the outer diameter ∆ D (mm) when the hood with thinning, which corresponds to the formula of the invention and is 112-109=3,0 (mm) at distribution, 124-121=3,0 (mm) when the hood with thinning, where ⌀109 mm - inner diameter of the workpiece before hand, ⌀112 mm - internal diameter of the billet after the deal before extraction with thinning, ⌀124 mm - outer diameter billet front hood, ⌀121 mm - outer diameter of the billet after extrusion with thinning.

When combined rotary press (1, 6) and press the rotary (figure 4, figure 5, Fig, 2) the treatment of the extract with thinning, crimping and distribution perform in the same way as in the above example 2.

Combined method of manufacture is also receiving corps press processing - crimping curved part (figure 4) and then machining - (turning) of the inner surface of the cylindrical and transition parts (figure 2), while the use of cold rolled tube ⌀122×6 mm (example 2) were 10 excellent brand. Swaging (figure 4) receive a curved portion of the same dimensions and mechanical properties. A cylindrical portion on the inner surface with the same dimensions (figure 2) is produced by turning on a lathe.

The execute method of manufacturing thin-walled shells of variable cross-section in accordance with the invention enables the manufacture of shells with high dimensional accuracy, surface quality, high performance with high efficiency metal, durability and reliability.

The invention can be used in the manufacture of thin-walled shells of variable cross-section of the vessel is at high pressure and shells of various sizes.

Specified positive effect is confirmed by the test pilot batches of shells produced by this method.

Currently developed technical documentation, tests, scheduled batch production under the proposed method.

1. A method of manufacturing thin-walled shells of variable cross-section, comprising forming a crimping one part of the billet and the hood another, characterized in that as the blanks using steel pipe calm brand with a tensile strength of 32÷65 kgf/mm2, forming perform rotational and/or forging machining of the workpiece with the formation of a curved transition and cylindrical parts with the axial direction of deformation, and initially treated with a transitional tapered and curved parts with wall thickness and tensile strength of the material increasing and the diameter decreases in the direction to obamamama end, then in the opposite direction - transitional part with variable wall thickness and cylindrical with thinning of the wall, when a transitional portion is formed with a cylindrical shoulder and a conical section with an angle of inclination of the generatrix, less 1.5÷2.5 times the angle of inclination of the generatrix of the transition portion at its initial processing, and at the end of processing to perform annealing, reducing n the voltage at a temperature of 340÷360°C.

2. The method according to claim 1, characterized in that the crimping curved parts perform wall thickness at the crimped end is 1,1÷1.5 wall thickness of the workpiece.

3. The method according to claim 1, characterized in that the crimping transition and curved parts perform with the tensile strength of the material in the direction of decreasing diameter toward the end face changed according to

where σin(kgf/mm2- the current value of the tensile strength;
σwish(kgf/mm2) - the original value of the tensile strength;
ε (%) - the degree of deformation of the crimping;
α° - current value of the angle of the taper.

4. The method according to claim 1, characterized in that the cylindrical band of the transition portion of the workpiece when the hood is formed with a length not exceeding the wall thickness of the workpiece.

5. The method according to claim 1, characterized in that the adapter part billet hood with thinning shape with a wall thickness of the conical section, decreasing in the direction from the curved portion to the cylindrical.

6. The method according to claim 1, wherein the forming of the workpiece carry out first rotary crimping transition and curved parts, and then extraction with thinning transition and cylindrical parts forging processing.

7. The method according to claim 1, wherein the forming of the workpiece carry out extrusion processing - in the beginning about the Imam curved, then the distribution of transition and cylindrical parts, and then rotating hood with wall reduction transition and cylindrical parts.

8. The method according to claim 1, characterized in that the degree of deformation of the cylindrical portion of the workpiece when the distribution is equal to the degree of deformation of the diameter change when the hood with thinning of the wall of the same part.

9. The method according to claim 1, characterized in that the crimping curved and cylindrical distribution and transition portions of the blanks performing press processing for one stroke of the press.

10. The method according to claim 1, characterized in that the degree of deformation during crimping curved part is 0.7÷0,9 degree of deformation in the hood with the thinning of the cylindrical part.



 

Same patents:

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FIELD: process engineering.

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EFFECT: improved mechanical properties.

2 cl, 2 ex, 4 dwg

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