EP0431775A2 - Verfahren zur kontinuerlichen Endbearbeitung von Rohren - Google Patents

Verfahren zur kontinuerlichen Endbearbeitung von Rohren Download PDF

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Publication number
EP0431775A2
EP0431775A2 EP90312467A EP90312467A EP0431775A2 EP 0431775 A2 EP0431775 A2 EP 0431775A2 EP 90312467 A EP90312467 A EP 90312467A EP 90312467 A EP90312467 A EP 90312467A EP 0431775 A2 EP0431775 A2 EP 0431775A2
Authority
EP
European Patent Office
Prior art keywords
pipes
pipe
rolls
stands
straightener
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP90312467A
Other languages
English (en)
French (fr)
Other versions
EP0431775A3 (en
Inventor
Kazuo C/O Patent & License Department Yamazaki
Shinji C/O Patent & License Department Akita
Fuyuhiko C/O Patent & License Dep. Kajiyama
Tetsuya C/O Patent & License Dep. Koura
Tetsuya C/O Patent & License Dep. Iwaide
Yoshioki C/O Patent & License Dep. Komiya
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Engineering Corp
Original Assignee
NKK Corp
Nippon Kokan Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP30192389A external-priority patent/JPH03165927A/ja
Priority claimed from JP30192289A external-priority patent/JPH03165926A/ja
Application filed by NKK Corp, Nippon Kokan Ltd filed Critical NKK Corp
Publication of EP0431775A2 publication Critical patent/EP0431775A2/de
Publication of EP0431775A3 publication Critical patent/EP0431775A3/en
Withdrawn legal-status Critical Current

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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
    • B21D3/02—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 by rollers
    • B21D3/04—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 by rollers arranged on axes skew to the path of the work

Definitions

  • This invention relates to the continuous finishing of pipe.
  • pipes are rolled or formed and finally processed in finishing facilities which are usually composed of a straightener, nondestructive inspection equipment and an end cutter.
  • pipes are cooled on a cooling bed, and the ends of the pipes are cut by an end cutter to a predetermined length.
  • the cut pipes are straightened and inspected for quality by nondestructive inspection facilities.
  • the conventional finishing method has the following problems:
  • a conventional rotary straightener is composed of three or four pairs of skewed concave rolls accommodated in stands.
  • Japanese laid-open Patent Publication No.123419/1986 discloses a method of straightening wherein the offset, or the deviation of the path line of bent pipes, and the crush, or the difference between the pipe diameter and the roll clearance of the straightener, are predetermined by a set of equations. However the ends of the pipe cannot be straightened by the method according to this publication.
  • Japanese laid-open Patent Publication No.18244/1985 discloses a method wherein the pressure of the rolls is dynamically adjusted to avoid crushing of pipe ends. However, it is very difficult to avoid crushing when the pipes are straightened at high speed.
  • the invention provides a method of continuous finishing of pipe comprising the steps of: straightening rolled pipes which have been cooled on a cooling bed; inspecting said straightened pipes by nondestructive inspection; and cutting the inspected pipes, to a predetermined length.
  • a high speed straightener having at least five roll pair stands can be utilized for the straightening step.
  • the number of the stands is preferably five but may be six or seven.
  • the plural pairs of the rolls of the stands adjacent to each other can co-operate to achieve the maximum offset.
  • the distance between adjacent ones of the stands is 750 to 850mm.
  • the skew angle of said pair of rolls is normally set in a range of from 35° to 50°.
  • the outer diameter of the pipe should be from 25.4mm to 153.7mm.
  • the speed of advance of the pipes is less than 4.0 m/sec.
  • a cutter is utilized for the cutting, which cuts plural pipes in one cycle.
  • a problem encountered in the conventional finishing of rolled pipes is that straightening and inspection in on-line operation is not sufficient to achieve the required quality. Therefore off-line operation is required, wherein additional operations have to be carried out. Moreover, pipes with a length of from 6 to 45m and with comparatively small diameter are straightened at a maximum speed of only 120 m/min, which is not sufficient for on-line operation. Hence the rolled pipes are cut, straightened and inspected by off-line operation.
  • the main obstacle in this on-line operation is the capacity, that is, the line speed of the straightener.
  • a rotary straightener 20 is arranged downstream of a rolled pipe cooling bed 10 and a nondestructive inspection device 30 is arranged downstream of the rotary straightener 20.
  • a pipe cutter 40 is arranged downstream of the nondestructive inspection device 30.
  • the nondestructive inspection device 30 is composed of a leakage flux detector; a thickness meter which may be an electromagnetic supersonic thickness meter or a supersonic thickness meter; and a meter which measures the outside diameter of the pipe.
  • the detecting capacity of the device is 192 m/min.
  • the cutter having a cutting grinder can cut the plural pipes in one cutting cycle which promotes cutting efficiency and cutting accuracy, and minimises burring.
  • the uninspected ends of the pipes are included in the crop ends.
  • a high speed straightener having five stands and five pairs of rolls is utilized in the straightening.
  • the rotary straightener is composed of five stands each of which incorporates two concave rolls skewed as for the pass line. The top and bottom rolls are skewed at the same absolute value of angle as for the pass line but in the positive and negative direction. As the rolls are rotated at the same speed, the pipe is spirally moved towards the delivery side.
  • the clearances between the top and the bottom rolls are set smaller than the outside diameter of the pipe to apply a plastic deformation.
  • the middle points of the clearances of the rolls at No.1, No.4 and No.5 are on the pass line.
  • the middle points of the clearances of the rolls at No.2 and No.3 are off the pass line which is called the offset of the rotary straightener.
  • the rate of rotation of the motor which drives the roll may be increased.
  • the rotational speed of the pipe increases, which gives rise to vibration of the pipe and may break the pipe.
  • the area of contact of the pipe with the rolls is decreased, which reduces the plastic deformation of the pipe, which is needed to straighten the pipe.
  • the rolls of No.1, No.3 and No.4 stands are on the line, or the middle point of the clearance between the top and the bottom roll of a stand on the pass line.
  • the rolls of No.2 stand are in an offset position.
  • the straightening deformation is carried out be a single bending with the maximum offset of d max .
  • the rolls of No.1, No.4 and No.5 are on the line and the rolls of No.2 and No.3 are in offset positions.
  • the quantity of the maximum offset can be increased without applying an excessive offset on a single stand which may cause a spirally shaped defect on the surface of the pipes.
  • the number of the stands of the rotary straightener is not limited to five but may be more than five. However when the number is increased, the chance of defect generation and the investment and the maintenance cost are increased. Therefore the number is limited to seven.
  • the distance between adjacent stands is preferably from 750 to 850 mm.
  • the distance is more than 850 mm, the leading end of the pipe is seized only with difficulty by the rolls.
  • the distance is less than 750 mm, a severe enough bending is difficult to impose on the pipes. Therefore the distance is determined to be from 750 to 850 mm.
  • range of outer diameters of the pipe wherein the invention is practicable is from 25.4 to 153.7 mm.
  • the angle of the rolls in a range of from 35° to 50°. are on the skew angle is less than 35°, the rotational speed of the roll is excessive and the pipe wall may be cut through during its straightening.
  • the skew angle is more than 50°, the area of contact of the pipe with the rolls is so low that a reasonable plastic deformation cannot be achieved.
  • the translational speed of advance of the pipes is preferably no more than 4.0 m/sec., since when the rotational speed of the pipe at the rotary straightener is over 3000 rpm, it may cause the breakage of the pipe even when the skew angle of the rolls is set as 50°.
  • the length of the pipes there is no limitation.
  • the upper limit of the length of the pipes is 45 m. However it may be 100 m or more. It depends on the overall capacity of the rolling mills.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Metal Extraction Processes (AREA)
EP19900312467 1989-11-22 1990-11-15 Method of continuous finishing of pipe Withdrawn EP0431775A3 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP30192389A JPH03165927A (ja) 1989-11-22 1989-11-22 小径長尺管の高速矯正機
JP301923/89 1989-11-22
JP301922/89 1989-11-22
JP30192289A JPH03165926A (ja) 1989-11-22 1989-11-22 長尺鋼管の精整設備

Publications (2)

Publication Number Publication Date
EP0431775A2 true EP0431775A2 (de) 1991-06-12
EP0431775A3 EP0431775A3 (en) 1991-07-10

Family

ID=26562928

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19900312467 Withdrawn EP0431775A3 (en) 1989-11-22 1990-11-15 Method of continuous finishing of pipe

Country Status (1)

Country Link
EP (1) EP0431775A3 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2587206A4 (de) * 2010-06-28 2014-10-08 Nippon Steel & Sumitomo Metal Corp Wärmeübertragungsrohr für dampferzeuger und herstellungsverfahren dafür

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3207289A (en) * 1963-04-29 1965-09-21 United States Steel Corp Apparatus for delivering pipe lengths sidewise as discharged from rotary straightener or the like
JPS5744624U (de) * 1980-08-21 1982-03-11
US4494394A (en) * 1981-07-06 1985-01-22 Nilsson Einar W Straightening machines and methods
DE3441537A1 (de) * 1984-11-14 1986-05-15 Th. Kieserling & Albrecht Gmbh & Co, 5650 Solingen Schraegrollenrichtmaschine mit mehr als 2 richtrollen
US4663955A (en) * 1986-02-18 1987-05-12 Roman Engineering Company, Inc. Apparatus for straightening tubing
DE3729619A1 (de) * 1987-09-04 1989-03-16 Reika Werk Gmbh Maschf Verfahren und einrichtung zum richten von laengsverschieblichen und um ihre laengsachse sich drehenden rohren

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2587206A4 (de) * 2010-06-28 2014-10-08 Nippon Steel & Sumitomo Metal Corp Wärmeübertragungsrohr für dampferzeuger und herstellungsverfahren dafür
US10488038B2 (en) 2010-06-28 2019-11-26 Nippon Steel Corporation Method for producing a heat transfer tube for steam generator using drawing, solution heat treatment, and straightening

Also Published As

Publication number Publication date
EP0431775A3 (en) 1991-07-10

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