Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D3/00—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts
  • B21D3/10—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts between rams and anvils or abutments
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C37/00—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
  • B21C37/06—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
  • B21C37/08—Making tubes with welded or soldered seams
  • B21C37/0807—Tube treating or manipulating combined with, or specially adapted for use in connection with tube making machines, e.g. drawing-off devices, cutting-off
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C37/00—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
  • B21C37/06—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
  • B21C37/30—Finishing tubes, e.g. sizing, burnishing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
  • B21D5/06—Bending sheet metal along straight lines, e.g. to form simple curves by drawing procedure making use of dies or forming-rollers, e.g. making profiles
  • B21D5/10—Bending sheet metal along straight lines, e.g. to form simple curves by drawing procedure making use of dies or forming-rollers, e.g. making profiles for making tubes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
  • B21D5/14—Bending sheet metal along straight lines, e.g. to form simple curves by passing between rollers

Definitions

• the invention relates to a method for producing steel tubes, in which a sheet or coil formed in a bending process to a round tube in cross-section, welded in a subsequent welding along the longitudinal edges facing each other for producing a longitudinal seam and then subjected to a relaxation treatment becomes.
• a method of this type is given in DE 10 2006 010 040 B3.
• the tube is compressed by means of a straightening machine from the outer circumference by means of a plurality of circumferentially offset, axially arranged rectilinear straightening for straightening, the straightening wear the straightening tube adapted to the shape of the tube outer cross section.
• the straightening can be individually or in dependence on each other z. B. hydraulically, wherein the operation controlled or regulated be made that can.
• the straightening cylinders with the straightening shells can direct the tube up to its circular contour, the calibration taking place with respect to the diameter and / or the ovality.
• An upsetting of the material beyond the yield point is also possible by means of this impanding, which is mentioned there for the first time.
• EP 0 438 205 A2 discloses a method and apparatus for straightening the ends of elongate workpieces.
• the workpiece is stationary, at least one selected in the end region cross-section of a swelling and declining bending alternating stress is subjected, with a predetermined maximum deflection one or more times revolves around the workpiece axis.
• a rising or falling bending stress is chosen so that the selected cross section is deformed into the plastic region.
• the means for generating a deflection of the workpiece axis in an orbit beyond the elastic limit of the workpiece also have at least three symmetrically arranged about a common axis, movable in the radial direction plunger, each connected to a path and time-dependent controllable piston-cylinder unit are and the plunger by a control of the linkage of the piston-cylinder units with each other during the straightening process out of phase perform a sinusoidal lifting movement.
• no judgment is made in terms of roundness or ovality, but a correction of deviations in the straightness of the bent ends, d. H. it's about a longitudinal straightening.
• a straightening machine for pipes shown in FR 737 123 A these are directed in their longitudinal direction, in a warm state.
• the straightening elements are z. B. rounded according to the diameter of the tube, wherein the inner part of the straightening elements can be interchangeable.
• the tubes are heated red and evacuated. After the longitudinal straightening thus carried out, the tubes are fed by means of an ejector to a cooling device.
• the straightening of large steel pipes is complicated with such measures, and problems and solutions to Rundricht do not go out of this document.
• DE 196 02 920 A1 discloses a method for producing pipes, in particular large pipes, in which the pipes are calibrated and directed after cold welding (expansion) after the internal and external welds.
• DE 41 24 689 A1 discloses a method and apparatus for eliminating form errors and degrading harmful internal stresses in longitudinal seam welded pipe strands also by widening of the tube, including an internal expanding mandrel is used. The expansion of the tubing takes place to such an extent that in the circumferential direction existing residual stresses are to be reduced as far as possible.
• a target diameter can be in this way with the straightening, although with a relatively high Set effort, but in particular over the pipe circumference thereby no compression strength of the material is achieved.
• the tools During expansion, the tools generate a uniform force on the inner side of the tube, which, when straightened, evenly guides the material into a circular shape. In this process, however, unfavorable stress conditions can be generated in the tubular body, whereby the compression strength and thus collapse resistance of the pipe can decrease.
• Coated pipes eg CLAD pipes
• CLAD pipes can also cause damage to the material, which often means that such pipes can not be calibrated using this process. Such adverse effects can be further increased with increasing degree of expansion.
• the invention has for its object to provide a method for producing large steel tubes, with which the production of high-quality pipes under the most accurate Rundricht and with the shortest possible production time is achieved, as well as appropriately trained pipes ready to provide, including the mechanical technological properties of the material should be improved.
• the target diameter can be set well, but in the process of Rundhouses is also a Relaxation treatment performed.
• the pipe tolerance in particular the ovality, improved by uniform plastic deformation of the material in a short time, but also the residual stress behavior of the tubular body.
• the stresses generated by the shaping of the Blechmateri- as generated mechanically in the base material but also reduced by the longitudinal seam welding of the tube-shaped sheet material caused thermally generated stresses.
• the mechanical properties of the pipe are improved by the method, namely z. B. the compression strength and the collapse resistance.
• the residual stress behavior after impregation is reduced to a minimum, whereby a virtually complete reduction in stress is made possible without a complex heat treatment (low-stress annealing at, for example, approx 600 ° C) is required, and disadvantages caused by the heat treatment can be avoided.
• Due to the uniform upsetting over the outer surface of the tube the residual stresses generated by the manufacturing process in the longitudinal and circumferential direction in the base material and in the weld build off.
• a reason for the improvements evidently lies in the fact that the residual stress state is reversed, ie after the impanding there is tension on the inside of the tube and compressive stress on the outside of the tube.
• the measures further contribute to the fact that, in straightening for relaxation, compression in the circumferential direction and hydraulic expansion (for example with hydrotester) are combined with one another.
• the impanding and hydraulic relaxation can also be carried out alternately and repeatedly.
• the straightening and the relaxation processes are facilitated by the fact that the straightening and relaxing is carried out by means of at least two, in the radial direction to the tube axis oppressive, staggered in the circumferential direction directional stamp with partially adapted to the peripheral contour of the tube sections straightening shells.
• a tube having advantageous properties is obtained by being produced by one of the above-mentioned methods.
• Fig. 1 is a arranged in a rotary straightening tube in a schematic cross-sectional view
• Fig. 2 is a schematic representation of manufacturing steps of a pipe.
• Fig. 1 shows an axial plan view of a tube 1 of a round cross section with an inner radius n and an outer radius r a , by the difference of a wall thickness t is set.
• the tube 1 has a longitudinally extending weld seam 2.
• Mechanical or thermal stress regions 3, 3 ' are present in the tube wall on the one hand as a result of the mechanical molding process and on the other as a result of the heat influences during welding.
• the straightening machine or straightening device 10 has a plurality of circumferentially evenly distributed and arranged in the same direction in the axial direction of the directional stamp with respective straightening cups 11, 12, 13, 14, which are interchangeably mounted on a respective holder 15 and on its side facing the tube 1 with a are provided on the surface contour of the tube 1 adapted surface shape, which extends in the circumferential direction along the pipe surface, so that when applying all straightening shells, the pipe surface is largely encompassed in the circumferential direction.
• the straightening cups 11, 12, 13, 14 only over a short section of the tube 1, wherein a plurality of such units of straightening cups 11, 12, 13, 14 can be arranged in the longitudinal direction of the tube 1 on the outer surface.
• straightening cups adapted to different pipe diameters can be easily inserted or exchanged.
• the holder 15 of the straightening shells 11, 12, 13, 14 are along a Guide axis 17 hydraulically adjusted in radial, oriented to the center of the tube 1 direction in the carrier 16 to cause a compression of the tubular body and a hydraulic expansion in the opposite direction under control or regulation by means of a control device 20.
• straightening can take place to predetermined inner or outer diameter, wherein an absolute position can be specified via the control device.
• Fig. 2 shows essential steps in the manufacture of the tube 1, namely a molding process a, in which a metal plate 4 by means of a molding device 30 by means of dies under advance of the metal plate 4 gradually to a bent part 1.1 and finally the circumferentially bent tubular body 1.2 is formed. Subsequently, the tubular body 1.2 is closed in a welding process b at its mutually facing edges, which were previously prepared for welding, by means of a longitudinal weld in a welding device 40.
• the molding processes and the welding result in mechanical and thermal stress ranges 3, 3 ', as mentioned above.
• a straightening process c under Rundbox of the tube 1 in which at the same time a relaxation treatment.
• the relaxation treatment may additionally be carried out in a subsequent step d with hydrostatic relaxation, e.g. be combined by means of hydrotester, wherein by means of a pressure medium in the tube interior an outwardly directed pressure p is generated on the inner tube surface.
• the residual stress behavior of the tubular body is significantly improved without additional heat treatment, at the same time negative influences, such as can occur through a heat treatment, for. B. in low-voltage annealing, be avoided.
• a heat treatment for. B. in low-voltage annealing
• the expansion process can be specifically influenced.
• pipe outside or inside pipe diameters can be set to specific values.
• the mechanical technological properties such as strength and thermal expansion coefficient of the pipe material can be positively influenced.
• the collapse behavior of the tube and the properties under fatigue stresses are improved. Overall, this makes it possible to produce high-quality, virtually stress-free tubes with high tube tolerances in a significantly shorter time compared to conventional production methods.
• the residual stress behavior after impanding depending on the degree of Impansi- on, can be reduced to a minimum, with a complete reduction in voltage is possible.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Heat Treatment Of Articles (AREA)
• Bending Of Plates, Rods, And Pipes (AREA)
• Forging (AREA)
• Heat Treatment Of Steel (AREA)
• Shaping Metal By Deep-Drawing, Or The Like (AREA)

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Applications Claiming Priority (2)

Publications (2)

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• 2008
  • 2008-06-06 DE DE102008027807A patent/DE102008027807B4/de not_active Expired - Fee Related
• 2009
  • 2009-05-28 PT PT09757221T patent/PT2285507E/pt unknown
  • 2009-05-28 UA UAA201014581A patent/UA103024C2/ru unknown
  • 2009-05-28 WO PCT/EP2009/003816 patent/WO2009146838A1/fr not_active Ceased
  • 2009-05-28 CN CN2009801210521A patent/CN102056687B/zh not_active Expired - Fee Related
  • 2009-05-28 AT AT09757221T patent/ATE523271T1/de active
  • 2009-05-28 EP EP09757221A patent/EP2285507B1/fr active Active
  • 2009-05-28 US US12/737,077 patent/US9156074B2/en active Active
  • 2009-05-28 JP JP2011512007A patent/JP5361996B2/ja not_active Expired - Fee Related
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  • 2009-05-28 CA CA2726132A patent/CA2726132C/fr not_active Expired - Fee Related
  • 2009-05-28 BR BRPI0915529-5A patent/BRPI0915529B1/pt active IP Right Grant
  • 2009-05-28 AU AU2009254199A patent/AU2009254199B2/en not_active Ceased
  • 2009-05-28 DK DK09757221.8T patent/DK2285507T3/da active
  • 2009-05-28 KR KR1020107028504A patent/KR20110022613A/ko not_active Ceased
  • 2009-05-28 RU RU2010154236/02A patent/RU2456108C1/ru active

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