WO2020138145A1 - Crushing test method for steel pipe for pipeline, manufacturing method for steel pipe for pipeline, and crushing test device - Google Patents

Crushing test method for steel pipe for pipeline, manufacturing method for steel pipe for pipeline, and crushing test device Download PDF

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Publication number
WO2020138145A1
WO2020138145A1 PCT/JP2019/050773 JP2019050773W WO2020138145A1 WO 2020138145 A1 WO2020138145 A1 WO 2020138145A1 JP 2019050773 W JP2019050773 W JP 2019050773W WO 2020138145 A1 WO2020138145 A1 WO 2020138145A1
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WIPO (PCT)
Prior art keywords
steel pipe
deformable body
test
test steel
pressure
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PCT/JP2019/050773
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French (fr)
Japanese (ja)
Inventor
隆洋 ▲崎▼本
久和 田近
恒久 半田
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Ｊｆｅスチール株式会社
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Application filed by Ｊｆｅスチール株式会社 filed Critical Ｊｆｅスチール株式会社
Priority to JP2020514774A priority Critical patent/JP6702525B1/en
Publication of WO2020138145A1 publication Critical patent/WO2020138145A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/02—Details
    • G01N3/04—Chucks

Definitions

  • the present invention relates to a crush test method for a pipeline steel pipe (outer diameter of about 300 to 1500 mm) laid on the deep sea floor, a method for manufacturing a pipeline steel pipe, and a crush test apparatus.
  • the pressure generating portion includes a pair of opposing walls arranged to face each other by sandwiching the test steel pipe from the axial direction so as to be in close contact with both end surfaces in the axial direction of the test steel pipe, and one outer peripheral edge portion of the pair of opposing walls.
  • a peripheral wall extending to the other side and surrounding the outer peripheral surface of the test steel pipe is provided, and a pair of opposing walls and the peripheral wall form a pressure chamber surrounding the outer periphery of the test steel pipe.
  • the fluid is supplied to the pressure chamber of the pressure generating part, and the pressurized fluid acts on the outer peripheral surface of the test steel pipe to deform the test steel pipe inward in the radial direction, and the strain sensor attached to the test steel pipe.
  • the crushing limit pressure until the test steel pipe is crushed is measured based on the change of the fluid pressure and the fluid pressure, and the crushing performance of the pipeline steel pipe is evaluated and predicted.
  • the test steel pipe is sandwiched from the axial direction so that the pair of opposing walls are in close contact with both end faces in the axial direction of the test steel pipe, even if the pressure chamber becomes high in pressure, the pressure chamber is forced from between the end face and the opposing wall. It is sealed without fluid leakage to the outside.
  • the present invention has been made by paying attention to the unsolved problem of the above-mentioned conventional example, and when the test steel pipe is deformed inward in the radial direction by the action of the pressurized fluid, it is formed on both end faces in the axial direction of the test steel pipe.
  • a crushing test method for a steel pipe for a pipeline a method for manufacturing a steel pipe for a pipeline, and a crushing test apparatus that can reproduce the crushing limit pressure of a steel pipe for a pipeline with high accuracy without generating frictional force.
  • the purpose is to
  • the crushing test method for a pipeline steel pipe is a ring-shaped test steel pipe formed by being cut from a part of the pipeline steel pipe, and a test steel pipe.
  • the step of supplying fluid to the pressure chamber formed surrounding the outer peripheral surface of the deformable body and causing the pressurized fluid to act on the outer peripheral surface of the deformable body the step of measuring the inner diameter of the test steel pipe, and the pressure of the fluid in the pressure chamber And a step of calculating the crushing limit pressure of the crushed test steel pipe based on the inner diameter measurement value of the test steel pipe and the pressure measurement value of the fluid in the pressure chamber.
  • the method for producing a steel pipe for a pipeline is a method for producing a steel pipe for a pipeline through the steps of performing the crushing test method for a steel pipe for a pipeline described above.
  • the crushing test apparatus for a steel pipe for a pipeline is a test steel pipe formed by cutting a part of a steel pipe for a pipeline to form a ring shape, and an axial length of the test steel pipe is increased. It is a cylindrical member that is set and formed of synthetic resin. The deformable body mounted on the outer circumference of the test steel pipe and the deformable body are clamped from the axial direction so that both axial end surfaces of the deformable body are in close contact with each other.
  • An apparatus main body that forms a pressure chamber that surrounds the outer periphery of the deformable body by including a pair of opposed walls that are arranged to face each other and a peripheral wall that extends from the pair of opposed walls and that surrounds the outer peripheral surface of the deformable body, Fluid supply means for supplying fluid to the pressure chamber, inner diameter measurement means for measuring the inner diameter of the test steel pipe, fluid pressure measurement means for measuring the pressure of the fluid in the pressure chamber, and inner diameter measurement value and fluid measured by the inner diameter measurement means And a calculating means for calculating the crush limit pressure of the crushed test steel pipe based on the pressure measurement value of the fluid measured by the pressure measuring means.
  • the manufacturing method of a pipeline steel pipe and the crushing test apparatus according to the present invention when the test steel pipe is deformed radially inward by the action of the pressurized fluid, No frictional force is generated on both end faces in the axial direction, and the crushing limit pressure of the pipeline steel pipe can be reproduced with high accuracy using the test steel pipe.
  • FIG. 1 It is sectional drawing which shows the crushing test apparatus of the steel pipe for pipelines of 1st Embodiment which concerns on this invention. It is a figure which shows the principal part of the crushing test apparatus of the steel pipe for pipelines of 1st Embodiment. It is a block diagram which shows the structure of the calculating part which comprises the crushing test apparatus of the steel pipe for pipelines of 1st Embodiment. It is a figure which shows the principal part of the crushing test apparatus of the steel pipe for pipelines of 2nd Embodiment. It is a figure which shows the principal part of the crushing test apparatus of the steel pipe for pipelines of 3rd Embodiment. It is a figure which shows the principal part of the crushing test apparatus of the steel pipe for pipelines of 4th Embodiment. It is a graph which shows inner diameter displacement of the test steel pipe which reproduced plastic crushing when a crushing test was performed.
  • first to third embodiments according to the present invention will be described with reference to the drawings.
  • the same or similar reference numerals are given to the same or similar parts.
  • the drawings are schematic and different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following description. Further, it is needless to say that the drawings include parts in which dimensional relationships and ratios are different from each other.
  • the following first to fourth embodiments exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is as follows: The shape, structure, arrangement, etc. are not specified below. Various changes can be added to the technical idea of the present invention within the technical scope defined by the claims described in the claims.
  • FIG. 1 and 2 show a crushing test apparatus for steel pipes for pipelines according to a first embodiment of the present invention.
  • a crushing test apparatus 1 for pipeline steel pipes according to the first embodiment sandwiches a test steel pipe 2, a deformable body 3 mounted on the outer periphery of the test steel pipe 2, and the deformable body 3 from an axial direction.
  • the apparatus main body 4 in which the test steel pipe 2 and the deformable body 3 are arranged, the pressurized water supply unit 5, the strain gauge 6, the pressure gauge 7, and the arithmetic unit 8 are provided.
  • the test steel pipe 2 is a member formed by cutting a part of a steel pipe for a pipeline for evaluating and predicting crush resistance performance to form a ring shape.
  • the test steel pipe 2 cut from the pipeline steel pipe is cut such that both axial end faces thereof are flat.
  • the deformable body 3 is a cylindrical member that is attached to the outer circumference of the test steel pipe 2 and is made of synthetic resin. Examples of the synthetic resin of the deformable body 3 include a nylon resin called NC nylon.
  • the thickness of the deformable body 3 is set to about 3 mm.
  • the inner diameter of the deformable body 3 may be the same as the outer diameter dimension of the test steel pipe 2 so as to be in close contact with the outer peripheral surface of the test steel pipe 2, but it is about 5 mm larger than the outer diameter dimension of the test steel pipe 2. However, it does not significantly affect the crush test.
  • the axial length Lc1 of the deformable body 3 is set longer than the axial length Lt1 of the test steel pipe 2, and the difference ⁇ L1 (in the axial length between the deformable body 3 and the test steel pipe 2).
  • Lc1-Lt1) is set in the range of 0.3 mm to 5.0 mm (0.3 ⁇ L1 ⁇ 5.0).
  • the device main body 4 includes a doughnut-shaped bottom plate 10 having a penetrating part 10a, a top plate 11 having the same outer peripheral shape as the bottom plate 10 and having a penetrating part 11a, and a bottom plate 10. And a ring-shaped intermediate plate 12 arranged coaxially between the roof 11 and the roof 11.
  • the intermediate plate 12 is arranged in a state of being fitted in annular step portions 10b and 11b provided on the outer peripheries of the surfaces of the bottom plate 10 and the top plate 11 facing each other.
  • grooves for inserting a sealing material are formed on the step surfaces extending along the axial direction of the step portions 10b and 11b and the inner wall surface of the intermediate plate 12 facing the step surfaces.
  • a packing is attached to maintain liquid tightness between the step portions 10b and 11b and the intermediate plate 12.
  • the shape of the groove and the shape of the rubber packing can be arbitrarily selected, and for example, the structure may be such that a rubber packing having a circular cross section or a rectangular cross section is mounted.
  • the apparatus main body 4 is provided with a ring-shaped test space ST surrounded by an upper surface 10h of the bottom board 10, a lower surface 11h of the top board 11, and an inner peripheral surface 12a of the intermediate board 12.
  • the test steel pipe 2 and the deformable body 3 are arranged so that the axis extends between the upper surface 10h of the bottom plate 10 and the lower surface 11h of the top plate 11.
  • a plurality of first connecting bolts 14 and second connecting bolts 15 are attached to the device body 4.
  • the plurality of first connecting bolts 14 pass through the through holes 11c, 12c which penetrate the axial direction at predetermined intervals in the outer circumferential side of the roof 11 and the intermediate plate 12, and the predetermined intervals in the circumferential direction of the bottom plate 10.
  • the threaded portion is screwed into the threaded hole 10c provided by opening.
  • the plurality of second bolts 15 pass through the through-holes 11d that penetrate through the axial direction in the circumferential direction on the inner circumferential side of the roof 11 at predetermined intervals, and set the predetermined intervals in the circumferential direction on the inner circumferential side of the bottom plate 10.
  • the screw portion is screwed into the screw hole 10d provided as above.
  • the bottom surface of the deformable body 3 By mounting the plurality of first and second connecting bolts 14 and 15, the bottom surface of the deformable body 3 in a state where both end surfaces 3a and 3b in the axial direction are in close contact with the lower surface 11h of the top 11 and the upper surface 10h of the bottom board 10. It is sandwiched between 10 and the roof 11.
  • a pressure chamber 16 is formed in a space surrounded by the outer peripheral surface of the deformable body 3, the inner peripheral surface of the intermediate plate 12, the lower surface 11h of the roof 11 and the upper surface 10h of the bottom plate 10.
  • a water supply passage 11e and a pressure measurement passage 11f, which communicate with the outside of the pressure chamber 16 and the apparatus body 4, are formed in the roof 11, and the pressurized water supply unit 5 is connected to the water supply passage 11e.
  • the pressure gauge 7 is connected to 11f. Further, a plurality of strain gauges 6 are attached to the inner peripheral surface of the test steel pipe 2.
  • the calculation unit 8 includes an input unit 8a, a crushing pressure calculation unit 8b, a display unit 8c, and the like.
  • the input unit 8a, the crushing pressure calculation unit 8b, and the display unit 8c are specifically realized by a general-purpose information processing device such as a personal computer or a workstation, and have, for example, a CPU, a ROM, a RAM, etc. as main components. In addition to being parts, they are connected by a network and are configured to exchange data.
  • the pressure value of the pressure chamber 16 measured by the pressure gauge 7 is input to the input section 8a of the calculation section 8, and the test steel pipe 2 measured by the plurality of strain gauges 6 mounted on the inner peripheral surface of the test steel pipe 2 is measured.
  • the displacement amount of is input.
  • the crushing pressure calculation unit 8b calculates the pressure when the test steel pipe 2 is crushed (crushing limit pressure) based on the change in the pressure value of the pressure chamber 16 input to the input unit 8a and the displacement amount of the test steel pipe 2.
  • the display unit 8c displays the value of the crush limit pressure of the test steel pipe 2 calculated by the crush pressure calculation unit 8b.
  • the pair of opposing walls described in the present invention correspond to the lower surface 11h of the top 11 and the upper surface 10h of the bottom board 10, and the fluid supply means described in the present invention corresponds to the pressurized water supply unit 5.
  • the inner diameter measuring means described in the present invention corresponds to the strain gauge 6, the fluid pressure measuring means described in the present invention corresponds to the pressure gauge 7, and the arithmetic means described in the present invention. , Corresponding to the calculation unit 8.
  • the deformable body 3 is attached to the outer circumference of the test steel pipe 2.
  • the test steel pipe 2 and the deformable body 3 are arranged in the test space ST of the apparatus main body 4 so that the axis extends between the upper surface 10h of the bottom plate 10 and the lower surface 11h of the top plate 11.
  • the plurality of first connecting bolts 14 and the second connecting bolts 15 are attached to the apparatus body 4, and both axial end surfaces 3a and 3b of the deformable body 3 are attached to the lower surface 11h of the roof 11 and the upper surface 10h of the bottom board 10.
  • the deformable body 3 is sandwiched between the bottom plate 10 and the top plate 11 in a state of being in close contact with each other.
  • the pressure chamber 16 is formed in the space surrounded by the outer peripheral surface of the deformable body 3, the inner peripheral surface of the intermediate plate 12, the lower surface 11h of the top 11 and the upper surface 10h of the bottom plate 10.
  • one end surface 2b in the axial direction is placed on the upper surface 10h of the bottom plate 10 and the other end surface 2a in the axial direction contacts the lower surface 11h of the roof 11. It is arranged inside the deformable body 3 in a state where it is not.
  • the pressurized water is supplied from the pressurized water supply unit 5 to the pressure chamber 16 via the water supply passage 11e.
  • the water pressure in the pressure chamber 16 is increased by the supply of the pressurized water from the pressurized water supply unit 5, the water pressure acts on the outer peripheral surface of the deformable body 3 and the deformable body 3 is plastically deformed radially inward.
  • the test steel pipe 2 mounted inside the deformable body 3 also plastically deforms radially inward.
  • the deformable body 3 is made of synthetic resin, even if the deformable body 3 is in close contact with the lower surface 11h of the roof 11 and the upper surface 10h of the bottom board 10, a large frictional force is not generated between the lower surface 11h and the upper surface 10h. Since the water pressure of the pressure chamber 16 acts on the outer circumference of the test steel pipe 2 via the deformable body 3, the test steel pipe 2 is likewise plastically deformed radially inward. At this time, in the test steel pipe 2, one end surface 2b in the axial direction is placed on the upper surface 10h of the bottom plate 10 and the other end surface 2a in the axial direction is not in contact with the lower surface 11h of the roof 11, so that the bottom plate 10 is not in contact. Since it is not sandwiched between the roof 11 and the roof 11, frictional force is not generated between the axial end surfaces 2a and 2b and the lower surface 11h and the upper surface 10h.
  • the calculation unit 8 inputs the pressure value of the water pressure of the pressure chamber 16 acting on the outer circumference of the test steel pipe 2 to the input unit 8a from the pressure gauge 7, and the displacement amount of the test steel pipe 2 plastically deformed radially inward. Since input is made from a plurality of strain gauges 6, the crush pressure calculation unit 8b calculates the crush limit pressure when the test steel pipe 2 is crushed based on the change in the pressure value of the pressure chamber 16 and the displacement amount of the test steel pipe 2. .. Then, the display unit 8c displays the value of the crushing limit pressure of the test steel pipe 2.
  • the test steel pipe 2 which is plastically deformed radially inward is also plastically deformed in the direction in which the axial length increases.
  • the difference ⁇ L1 between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is set to 0.3 mm or more, but this difference ⁇ L1 (0.3 mm or more) is Even if the test steel pipe 2 is plastically deformed in the direction in which the axial length increases, the axial end surface of the test steel pipe 2 does not come into contact with the lower surface 11h of the roof 11. As a result, even if the test steel pipe 2 is plastically deformed in the direction in which the axial length increases, there is no possibility of generating a frictional force between the top plate 11 and the bottom plate 10.
  • the difference ⁇ L1 between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is less than 0.3 mm, the end surface of the test steel pipe 2 comes into contact with the lower surface 11h of the roof 11, so the test A frictional force may be generated between the steel pipe 2 and the top 11 and the bottom 10. Further, if the difference ⁇ L1 between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is too large, the deformable body 3 is excessively deformed by the action of water pressure in the pressure chamber 16, and the deformable body is deformed.
  • the liquid-tightness of the contact position between the axial end surface 3a of 3 and the lower surface 11h of the roof 11 and the contact position between the axial end surface 3b of the deformable body 3 and the upper surface 10h of the bottom plate 10 may deteriorate. Therefore, in the first embodiment, by setting the difference ⁇ L1 to a value of 5.0 mm or less, excessive deformation of the deformable body 3 is prevented, and the liquid at the contact position between the bottom board 10 and the roof 11 and the deformable body 3 is prevented. The tightness is secured.
  • the pressure chamber 16 that applies water pressure to the outer peripheral surface of the test steel pipe 2 to be subjected to the crush test includes the outer peripheral surface of the deformable body 3 mounted on the outer peripheral surface of the test steel pipe 2, the inner peripheral surface of the intermediate plate 12, It is formed in a space surrounded by a lower surface 11h of the top 11 and an upper surface 10h of the bottom 10. Then, the water pressure of the pressure chamber 16 acts on the test steel pipe 2 via the deformable body 3 and plastically deforms inward in the radial direction.
  • one end surface 2b in the axial direction is the bottom plate. 10
  • the other axial end surface 2a is not in contact with the lower surface 11h of the roof 11, and the axial end surfaces 2a and 2b generate a frictional force between the lower surface 11h and the upper surface 10h. do not do.
  • the crushing limit pressure of the pipeline steel pipe can be reproduced with high accuracy in the test steel pipe 2, and the pressure crushing performance of the pipeline steel pipe is highly accurate. Can be evaluated. Further, since the difference ⁇ L1 (Lc1-Lt1) between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is set to 0.3 mm or more, the test steel pipe 2 has an increased axial length. Even if it is plastically deformed in the direction in which it does not contact the lower surface 11h of the roof 11 and no frictional force is generated between it and the roof 11, the pressure crushing performance of the pipeline steel pipe can be evaluated with higher accuracy.
  • FIG. 4 shows a main part of a crushing test apparatus 17 for pipeline steel pipes according to a second embodiment of the present invention.
  • the same components as those of the crushing test apparatus 1 for a steel pipe for a pipeline according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
  • ring grooves are formed on the step surfaces along the axial direction of the step portions 10b and 11b shown in the first embodiment and on the inner wall surface of the intermediate plate 12 facing the step surfaces.
  • a ring groove having a quadrangular cross section is formed on the step surfaces orthogonal to the axial direction of the step portions 10b and 11b and the axial surface of the intermediate disk 12 facing the step surfaces.
  • An annular packing 23 having a rectangular cross section is attached to the ring grooves formed on the surfaces of the step portions 10b and 11b and the intermediate plate 12 that face each other in the axial direction.
  • the axial force generated in the first and second connecting bolts 14 and 15 by passing through the roof 11 and being screwed into the bottom plate 10 causes a step difference perpendicular to the axial direction of the step parts 10b and 11b. Since a large adhesion force acts on the annular packing 23 mounted between the surface and the surface of the intermediate plate 12 facing the surface and orthogonal to the axial direction, the water pressure in the pressure chamber 16 is increased as compared with the first embodiment. It is possible to greatly increase it. Therefore, the crushing test apparatus 17 for steel pipes for pipelines of the second embodiment measures the crushing limit pressure of the test steel tube 2 by significantly increasing the water pressure of the pressure chamber 16 as compared with the crushing test apparatus 1 of the first embodiment. Therefore, the crushing limit pressure of a significantly high value of the pipeline steel pipe can be reproduced with high accuracy in the test steel pipe 2.
  • the annular packing 23 is attached to the ring groove provided on the step surface orthogonal to the axial direction of the step portions 10b and 11b and the surface orthogonal to the axial direction of the intermediate plate 12 facing the step surface. Even if an arc-shaped ring groove is formed and an O-ring is attached to this ring groove, the same effect can be obtained.
  • FIG. 5 shows a main part of a crushing test apparatus for steel pipes for pipelines according to a third embodiment of the present invention.
  • the same components as those of the crushing test device for pipeline steel pipes according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
  • a cylindrical rubber packing 21 is attached to the outer periphery of the deformable body 3.
  • the rubber packing 21 is a member in which thick portions 21a and 21b are provided at both ends in the axial direction, and the thickness other than the thick portions 21a and 21b is 3 mm, and the axial length in the free length is It is set to be longer than the axial length Lc2 of the deformable body 3. Further, the thick portions 21a and 21b are not always necessary, and the effect of the present invention can be exhibited without the thick portions.
  • the axial length Lc2 of the deformable body 3 is set longer than the axial length Lt2 of the test steel pipe 2, and the difference ⁇ L2 (Lc2-Lt2) between the axial lengths of the deformable body 3 and the test steel pipe 2 is , 1.0 mm or more and 1.3 mm or less (1.0 ⁇ L2 ⁇ 1.3).
  • the cylindrical elastic body described in the present invention corresponds to the rubber packing 21.
  • the deformable body 3 is attached to the outer periphery of the test steel pipe 2, and the rubber packing 21 is attached to the outer periphery of the deformable body 3.
  • the test steel pipe 2, the deformable body 3, and the rubber packing 21 are arranged so that the axis extends between the upper surface 10h of the bottom plate 10 and the lower surface 11h of the roof 11.
  • the plurality of first connecting bolts 14 and the second connecting bolts 15 are attached to the apparatus body 4, and both axial end surfaces 3a and 3b of the deformable body 3 are attached to the lower surface 11h of the roof 11 and the upper surface 10h of the bottom board 10.
  • the thickened portions 21a and 21b at both ends of the rubber packing 21 in the axial direction are elastically deformed in a compressed state so as to sandwich the deformable body 3 between the bottom plate 10 and the top plate 11.
  • the pressure chamber 16 is formed in a space surrounded by the outer peripheral surface of the rubber packing 21, the inner peripheral surface of the intermediate plate 12, the lower surface 11h of the top 11 and the upper surface 10h of the bottom plate 10.
  • one end surface 2b in the axial direction is placed on the upper surface 10h of the bottom plate 10 and the other end surface 2a in the axial direction does not contact the lower surface 11h of the roof 11, and the deformable body 3 is deformed. Placed inside.
  • the pressurized water is supplied from the pressurized water supply unit 5 to the pressure chamber 16 via the water supply passage 11e.
  • the water pressure in the pressure chamber 16 increases due to the supply of the pressurized water from the pressurized water supply unit 5, the water pressure acts on the outer peripheral surface of the deformable body 3 via the rubber packing 21, and the deformable body 3 is plastically deformed radially inward. It transforms.
  • the test steel pipe 2 mounted inside the deformable body 3 also plastically deforms radially inward.
  • one end face 2b in the axial direction is placed on the upper face 10h of the bottom plate 10, and the other end face 2a in the axial direction contacts the lower face 11h of the roof 11. Since it is not sandwiched between the bottom plate 10 and the top plate 11, no frictional force is generated between the axial end faces 2a and 2b and the lower face 11h and the upper face 10h.
  • the test steel pipe 2 is plastically deformed inward in the radial direction and is also plastically deformed in a direction in which the axial length is increased.
  • the difference ⁇ L1 between the axial length Lc2 of the deformable body 3 and the axial length Lt2 of the test steel pipe 2 is set to 1.0 mm or more, but this difference ⁇ L2 (1.0 mm or more) is set. Even if the test steel pipe 2 is plastically deformed in the direction in which the axial length increases, the axial end surface of the test steel pipe 2 does not come into contact with the lower surface 11h of the roof 11.
  • the test steel pipe 2 is plastically deformed in the direction in which the axial length increases, there is no possibility of generating a frictional force between the top plate 11 and the bottom plate 10.
  • the difference ⁇ L2 by setting the difference ⁇ L2 to a value of 1.3 mm or less, excessive deformation of the deformable body 3 is prevented, and the liquid at the contact position between the bottom plate 10 and the roof 11 and the deformable body 3 is prevented. The tightness is secured.
  • the water pressure of the pressure chamber 16 acts on the test steel pipe 2 via the deformable body 3 and plastically deforms inward in the radial direction.
  • one end face 2b in the axial direction is the top face 10h of the bottom plate 10h.
  • the other end surface 2a in the axial direction is not in contact with the lower surface 11h of the roof 11, and the axial end surfaces 2a and 2b do not generate frictional force between the lower surface 11h and the upper surface 10h.
  • the rubber packing 21 is attached to the outer periphery of the deformable body 3, and when the deformable body 3 is sandwiched between the bottom plate 10 and the top plate 11, the rubber packing 21 moves in the axial direction of the rubber packing 21.
  • the thick portions 21a and 21b at both ends are elastically deformed in a compressed state on the lower surface 11h of the top board 11 and the upper surface 10h of the bottom board 10.
  • the crushing test apparatus 20 of the third embodiment can measure the high value of the crushing limit pressure of the test steel pipe 2 by increasing the water pressure in the pressure chamber 16, and the high value of the crushing limit pressure of the pipeline steel pipe can be measured. Can be reproduced with high precision using a test steel pipe.
  • the test steel pipe 2 Even if is plastically deformed in the direction of increasing the axial length, the lower surface 11h of the roof 11 does not come into contact with the roof 11 and no frictional force is generated between the roof 11 and the pressure crushing performance of the pipeline steel pipe. It can be performed with high accuracy, and the crush limit pressure of the test steel pipe 2 can be calculated with high accuracy.
  • FIG. 6 shows an essential part of a crushing test apparatus for pipeline steel pipes according to a fourth embodiment of the present invention.
  • the same components as those of the crushing test apparatus 20 for pipeline steel pipes according to the third embodiment shown in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.
  • annular notches 3c and 3d are formed on the outer peripheral sides of the axially opposite end faces 3a and 3b of the deformable body 3, and the notches 3c and 3d have O Rings 31 and 32 are attached.
  • the difference ⁇ L2 (Lc2-Lt2) between the axial length Lc2 of the deformable body 3 and the axial length Lt2 of the test steel pipe 2 is 1.0 ⁇ L2 ⁇ 1.3. Is set to.
  • the annular recesses described in the present invention correspond to the annular notches 3c and 3d, and the O-rings described in the present invention correspond to the O-rings 31 and 32.
  • the deformable body 3 is mounted on the outer circumference of the test steel pipe 2, and the O-rings 31, 32 are provided in the annular cutouts 3c, 3d provided on both end faces 3a, 3b of the deformable body 3. Put on. Then, in the test space ST of the apparatus body 4, the deformable body 3 in which the test steel pipe 2 and the O-rings 31, 32 are mounted is arranged so that the axis extends between the upper surface 10h of the bottom plate 10 and the lower surface 11h of the top plate 11. To do.
  • first connecting bolts 14 and second connecting bolts 15 are attached to the device body 4, and both axial end faces 3a and 3b of the deformable body 3 are closely attached to the lower surface 11h of the roof 11 and the upper surface 10h of the bottom board 10. Then, the O-rings 31 and 32 are elastically deformed to the lower surface 11h and the upper surface 10h in a compressed state, and the deformable body 3 is sandwiched between the bottom plate 10 and the top plate 11. As a result, the pressure chamber 16 is formed in the space surrounded by the outer peripheral surface of the deformable body 3, the inner peripheral surface of the intermediate plate 12, the lower surface 11h of the top 11 and the upper surface 10h of the bottom plate 10.
  • one end surface 2b in the axial direction is placed on the upper surface 10h of the bottom plate 10 and the other end surface 2a in the axial direction does not contact the lower surface 11h of the roof 11, and the deformable body 3 is deformed. Placed inside.
  • the O-rings 31 and 32 are attached to both end surfaces 3a and 3b of the deformable body 3, and when the deformable body 3 is sandwiched between the bottom plate 10 and the top plate 11, The O-rings 31 and 32 are elastically deformed on the lower surface 11h of the top 11 and the upper surface 10h of the bottom 10 in a compressed state.
  • the crushing test apparatus 30 of the fourth embodiment also has higher liquid-tightness at the contact position between the bottom plate 10 and the roof 11 and the deformable body 3, as compared with the crushing test apparatus 1 of the first embodiment.
  • the water pressure in the pressure chamber 16 can be increased.
  • the crushing test apparatus 30 of the fourth embodiment can measure the high value of the crushing limit pressure of the test steel pipe 2 by increasing the water pressure in the pressure chamber 16, and the high value of the crushing limit pressure of the pipeline steel pipe can be measured. Can be reproduced with high precision using a test steel pipe. Further, by performing a crush test using the crush test devices 1, 17, 20, 30 of the first to fourth embodiments, it is possible to manufacture a steel pipe for pipeline in which a crush limit pressure with high accuracy is set. it can.
  • Example 1 Next, the measurement of the crush limit pressure by the crush test method using the crush test device for pipeline steel pipe according to the present invention, and the measurement of the crush limit pressure by the crush test method using the conventional crush test device, The effects of the present invention were verified by making a comparison as shown in Table 1 above.
  • Inventive Example 1 to Inventive Example 5 are measurement results using the crushing test apparatus 1 of the first embodiment in which the deformable body 3 is mounted on the outer circumference of the test steel pipe 2.
  • Examples 4 and 5 of the present invention are measurement results using the crushing test apparatus 20 of the second embodiment in which the deformable body 3 is mounted on the outer circumference of the test steel pipe 2 and the rubber packing 21 is mounted on the outer circumference of the deformable body 3. is there.
  • the crushing limit pressures of Inventive Example 1 to Inventive Example 5 and Comparative Examples 1 and 2 are the result of measuring the actual pipe without cutting a part of the pipeline steel pipe (actual pipe test result) and the pipeline.
  • the result (crushing device result) measured by the crushing test device of the first and third embodiments using the test steel pipe 2 obtained by cutting a part of the steel pipe for use is shown, and the actual pipe test result and the crushing device result are compared.
  • the measurement accuracy was shown.
  • examples 1 to 3 the frictional force is not generated in the test steel pipe 2 when the crushing test is performed by mounting the deformable body 3 on the outer periphery of the test steel pipe 2. Since the difference ⁇ L1 between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is set to 0.3 mm ⁇ L1 ⁇ 5.0 mm, the measurement accuracy error is 0.5%. It is within.
  • the deformable body 3 was attached to the outer circumference of the test steel pipe 2, and the rubber packing 21 was attached to the outer peripheral side of the deformable body 3, so that the test steel pipe 2 was not subjected to the crush test. Since no frictional force is generated and the difference ⁇ L2 between the axial length Lc2 of the deformable body 3 and the axial length Lt2 of the test steel pipe 2 is set to 1.0 mm ⁇ L2 ⁇ 1.3 mm, The error is less than 1.0%.
  • Comparative Example 2 the measurement error is 10% or more.
  • This comparative example 2 uses the crushing test apparatus 1 of the first embodiment in which the deformable body 3 is mounted on the outer circumference of the test steel pipe 2, but the difference ⁇ L1 in the axial length between the deformable body 3 and the test steel pipe 2 is used. It exceeds 5.0 mm.
  • the deformable body 3 is deformed in a state of entering between the end surface of the test steel pipe 2 and the lower surface 11h of the roof 11 and the liquid tightness of the pressure chamber 16 is increased. Became impossible, and the maximum pressure of the pressure chamber 16 was greatly reduced before the test steel pipe 2 was crushed.
  • the method using the crushing test apparatus 1 according to the first embodiment of the present invention and the method using the crushing test apparatus 20 according to the third embodiment are highly accurate in determining the crushing limit pressure of the steel pipe for pipeline with the test steel pipe. It was confirmed that it can be reproduced.
  • the method using the crushing test apparatus 30 of the fourth embodiment can also accurately reproduce the crushing limit pressure of the pipeline steel pipe with the test steel pipe.
  • the crushing limit pressure is measured by the crushing test method using the crushing test device for pipeline steel pipes according to the present invention, and the crushing limit pressure is measured by the crushing test method using the conventional crushing test device.
  • the effect of the present invention was verified by determining whether crushing was reproduced. Whether or not the plastic crush is reproduced is determined from the elastic deformation line of the test steel pipe 2 and the inner diameter displacement ⁇ R (average value of the measured inner diameter change) of the test steel pipe 2 subjected to the crush test calculated by the following formula (1). Judgment is made by comparison with the amount of separation, and when the inner diameter displacement ⁇ R of the test steel pipe 2 is more than 0.2% from the elastic deformation line, it is judged that the plastic indentation is reproduced.
  • ⁇ R -(PR 2 )/(tE) .
  • P is the pressure (Mpa)
  • R is the initial inner diameter (mm) of the test steel pipe 2
  • t is the thickness (mm) of the test steel pipe 2
  • E is the Young's modulus (Mpa).
  • Inventive Example 6 and Comparative Example 3 used steel pipes for pipelines having a nominal pipe thickness of 40 mm, a nominal outer diameter of 691 mm, the same outer diameter shape, and the same steel pipe characteristics.
  • the deformable body 3 is mounted on the outer circumference of the test steel pipe 2, and the shaft generated in the first and second connecting bolts 14 and 15 by penetrating the roof 11 and being screwed into the bottom 10
  • the force exerts a large adhesion force on the annular packing 23 mounted between the step surfaces of the step portions 10b and 11b which are orthogonal to the axial direction and the surface of the intermediate plate 12 which faces the step surfaces and which is orthogonal to the axial direction, and the pressure is applied.
  • FIG. 7 shows the relationship between the water pressure change and the inner diameter displacement of the pressure chamber 16 for the test steel pipe 2 of the present invention example 6.
  • the test steel pipe 2 of the present invention example 6 plastically deforms as the water pressure of the pressure chamber 16 increases. It was verified that the plastic indentation was reproduced when the distance from the elastic deformation line was 0.8%. It was also verified that when the plastic indentation of Inventive Example 6 was reproduced, a crushing test at an ultrahigh pressure exceeding 50 MPa could be reproduced.

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Abstract

A cylindrical deformation body (3), which has been made from a synthetic resin and is longer in the axial direction than a test steel pipe (2) consisting of a portion of a steel pipe for a pipeline that has been cut off so as to be formed into a ring shape, is fit onto the outer periphery of the test steel pipe. Next, the test steel pipe and deformation body are disposed such that the axes thereof extend along the space between a pair of opposing walls (10, 11) disposed so as to oppose each other. The pair of opposing walls sandwich the deformation body such that both axial-direction end surfaces (3a, 3b) of the deformation body are in close contact with the pair of opposing walls. Subsequently, a fluid is supplied to a pressure chamber (16) formed by surrounding the outer peripheral surface of the deformation body with the pair of opposing walls and a peripheral wall (12a) opposing the outer peripheral surface of the deformation body, and the fluid is pressurized and made to act on the outer peripheral surface of the deformation body. Next, the inner diameter of the test steel pipe is measured, the pressure of the fluid in the pressure chamber is measured, and the crushing limit pressure of the crushed test steel pipe is calculated on the basis of these measured values.

Description

パイプライン用鋼管の圧潰試験方法、パイプライン用鋼管の製造方法及び圧潰試験装置Crush test method for steel pipe for pipeline, manufacturing method of steel pipe for pipeline, and crush test apparatus
　本発明は、深海海底に敷設されるパイプライン用鋼管（外径３００～１５００mm程度）の圧潰試験方法、パイプライン用鋼管の製造方法及び圧潰試験装置に関する。 The present invention relates to a crush test method for a pipeline steel pipe (outer diameter of about 300 to 1500 mm) laid on the deep sea floor, a method for manufacturing a pipeline steel pipe, and a crush test apparatus.
　近年、エネルギー需要の増大に伴い、原油や天然ガスの長距離輸送方法としてパイプラインの重要性が高まっている。油田やガス田と供給基地との間のパイプラインの一部を深海海底に設ける場合、例えば水深２０００～３０００ｍ程度の海底に沈めても水圧に耐えるパイプライン用鋼管を選定する必要がある。パイプライン用鋼管を選定する手段の一つとして、海底の水圧と同程度の流体圧力が鋼管外周に作用しても圧潰が生じない耐圧潰性能を評価・予測する試験がある（例えば、特許文献１）。 In recent years, along with the increase in energy demand, the importance of pipelines as a long-distance transportation method for crude oil and natural gas has increased. When a part of the pipeline between the oil field or gas field and the supply base is provided on the deep sea floor, it is necessary to select a steel pipe for a pipeline that can withstand the water pressure even if it is submerged at a depth of about 2000 to 3000 m. As one of the means for selecting a steel pipe for a pipeline, there is a test for evaluating and predicting a crush resistance performance in which crushing does not occur even if a fluid pressure similar to the water pressure of the seabed acts on the outer circumference of the steel pipe (for example, Patent Document 1).
　特許文献１記載の管試験は、パイプライン用鋼管の一部を切断してリング形状の試験鋼管を形成し、この試験鋼管を圧力発生部に装着する。圧力発生部は、試験鋼管の軸方向の両端面に密着するように試験鋼管を軸方向から挟持して互いに対向配置されている一対の対向壁と、一対の対向壁の一方の外周縁部から他方に延在して試験鋼管の外周面を囲む周壁とを備え、一対の対向壁及び周壁で前記試験鋼管の外周を囲む圧力室を形成している。 In the pipe test described in Patent Document 1, a part of the steel pipe for pipeline is cut to form a ring-shaped test steel pipe, and this test steel pipe is attached to the pressure generating part. The pressure generating portion includes a pair of opposing walls arranged to face each other by sandwiching the test steel pipe from the axial direction so as to be in close contact with both end surfaces in the axial direction of the test steel pipe, and one outer peripheral edge portion of the pair of opposing walls. A peripheral wall extending to the other side and surrounding the outer peripheral surface of the test steel pipe is provided, and a pair of opposing walls and the peripheral wall form a pressure chamber surrounding the outer periphery of the test steel pipe.
　そして、圧力発生部の圧力室に流体を供給していき、加圧された流体が試験鋼管の外周面に作用することで試験鋼管を径方向内方に変形させ、試験鋼管に装着した歪センサと流体圧力との変化に基づいて試験鋼管が圧潰に至るまでの圧潰限界圧力を測定し、パイプライン用鋼管の耐圧潰性能の評価及び予測を行っている。ここで、一対の対向壁が試験鋼管の軸方向の両端面に密着するように試験鋼管を軸方向から挟持しているので、圧力室が高圧になっても端面及び対向壁の間から圧力室外部への流体漏れが発生せずシールされる。 Then, the fluid is supplied to the pressure chamber of the pressure generating part, and the pressurized fluid acts on the outer peripheral surface of the test steel pipe to deform the test steel pipe inward in the radial direction, and the strain sensor attached to the test steel pipe. The crushing limit pressure until the test steel pipe is crushed is measured based on the change of the fluid pressure and the fluid pressure, and the crushing performance of the pipeline steel pipe is evaluated and predicted. Here, since the test steel pipe is sandwiched from the axial direction so that the pair of opposing walls are in close contact with both end faces in the axial direction of the test steel pipe, even if the pressure chamber becomes high in pressure, the pressure chamber is forced from between the end face and the opposing wall. It is sealed without fluid leakage to the outside.
特許第５１２３３２７号公報Japanese Patent No. 5123327
　しかし、特許文献１の管試験は、試験鋼管が径方向内方に変形する際に、一対の対向壁に密着している試験鋼管の軸方向の両端面に摩擦力が発生するので、試験鋼管が圧潰に至るまでの圧潰限界圧力が高い値を示すおそれがある。したがって、特許文献１の管試験は、圧潰限界圧力が高い値を示すことで、パイプライン用鋼管の耐圧潰性能を過大評価してしまうおそれがある。 However, in the pipe test of Patent Document 1, when the test steel pipe is deformed inward in the radial direction, a frictional force is generated on both axial end faces of the test steel pipe that is in close contact with the pair of opposing walls. There is a risk that the crushing limit pressure until the crushing will show a high value. Therefore, in the pipe test of Patent Literature 1, there is a possibility that the pressure crushing performance of the steel pipe for a pipeline may be overestimated because the crushing limit pressure shows a high value.
　本発明は、上記従来例の未解決の課題に着目してなされたものであり、加圧流体の作用で試験鋼管が径方向内方に変形する際には試験鋼管の軸方向の両端面に摩擦力が発生せず、パイプライン用鋼管の圧潰限界圧力を試験鋼管で高精度に再現することができるパイプライン用鋼管の圧潰試験方法、パイプライン用鋼管の製造方法及び圧潰試験装置を提供することを目的としている。 The present invention has been made by paying attention to the unsolved problem of the above-mentioned conventional example, and when the test steel pipe is deformed inward in the radial direction by the action of the pressurized fluid, it is formed on both end faces in the axial direction of the test steel pipe. Provided are a crushing test method for a steel pipe for a pipeline, a method for manufacturing a steel pipe for a pipeline, and a crushing test apparatus that can reproduce the crushing limit pressure of a steel pipe for a pipeline with high accuracy without generating frictional force. The purpose is to
　上記目的を達成するために、本発明の一態様に係るパイプライン用鋼管の圧潰試験方法は、パイプライン用鋼管の一部より切断され形成されたリング形状の試験鋼管の外周に、試験鋼管に対して軸方向長さを長く設定して合成樹脂で形成した円筒形状の変形体を装着する工程と、互いに対向配置した一対の対向壁の間を軸が延在するように試験鋼管及び変形体を配置し、一対の対向壁に変形体の軸方向の両端面が密着した状態で一対の対向壁で変形体を挟持する工程と、一対の対向壁及び変形体の外周面に対向する周壁で変形体の外周面を囲んで形成した圧力室に流体を供給し、変形体の外周面に加圧した流体を作用させる工程と、試験鋼管の内径を測定する工程と、圧力室の流体の圧力を測定する工程と、試験鋼管の内径測定値及び圧力室の流体の圧力測定値に基づいて圧潰した試験鋼管の圧潰限界圧力を演算する工程と、を備えている。 In order to achieve the above object, the crushing test method for a pipeline steel pipe according to an aspect of the present invention is a ring-shaped test steel pipe formed by being cut from a part of the pipeline steel pipe, and a test steel pipe. On the other hand, a step of mounting a cylindrical deformable body made of synthetic resin with a long axial length set, and a test steel pipe and deformable body so that the axis extends between a pair of opposing walls arranged to face each other. And a step of sandwiching the deformable body between the pair of opposing walls in a state where both end faces in the axial direction of the deformable body are in close contact with the pair of opposing walls, and a peripheral wall facing the outer peripheral surface of the pair of opposing walls and the deformable body. The step of supplying fluid to the pressure chamber formed surrounding the outer peripheral surface of the deformable body and causing the pressurized fluid to act on the outer peripheral surface of the deformable body, the step of measuring the inner diameter of the test steel pipe, and the pressure of the fluid in the pressure chamber And a step of calculating the crushing limit pressure of the crushed test steel pipe based on the inner diameter measurement value of the test steel pipe and the pressure measurement value of the fluid in the pressure chamber.
　また、本発明の一態様に係るパイプライン用鋼管の製造方法は、上述したパイプライン用鋼管の圧潰試験方法を行う工程を経てパイプライン用鋼管の製造を行う方法である。 The method for producing a steel pipe for a pipeline according to an aspect of the present invention is a method for producing a steel pipe for a pipeline through the steps of performing the crushing test method for a steel pipe for a pipeline described above.
　また、本発明の一態様に係るパイプライン用鋼管の圧潰試験装置は、パイプライン用鋼管の一部を切断してリング形状に形成した試験鋼管と、試験鋼管に対して軸方向長さを長く設定して合成樹脂で形成した円筒形状の部材であり、試験鋼管の外周に装着される変形体と、変形体の軸方向の両端面が密着するように変形体を軸方向から挟持して互いに対向配置されている一対の対向壁と、当該一対の対向壁から延在して変形体の外周面を囲む周壁とを備えて変形体の外周を囲む圧力室を形成している装置本体と、圧力室に流体を供給する流体供給手段と、試験鋼管の内径を測定する内径測定手段と、圧力室の流体の圧力を測定する流体圧力測定手段と、内径測定手段で測定した内径測定値及び流体圧力測定手段で測定した流体の圧力測定値に基づいて圧潰した試験鋼管の圧潰限界圧力を演算する演算手段と、を備えている。 Further, the crushing test apparatus for a steel pipe for a pipeline according to an aspect of the present invention is a test steel pipe formed by cutting a part of a steel pipe for a pipeline to form a ring shape, and an axial length of the test steel pipe is increased. It is a cylindrical member that is set and formed of synthetic resin.The deformable body mounted on the outer circumference of the test steel pipe and the deformable body are clamped from the axial direction so that both axial end surfaces of the deformable body are in close contact with each other. An apparatus main body that forms a pressure chamber that surrounds the outer periphery of the deformable body by including a pair of opposed walls that are arranged to face each other and a peripheral wall that extends from the pair of opposed walls and that surrounds the outer peripheral surface of the deformable body, Fluid supply means for supplying fluid to the pressure chamber, inner diameter measurement means for measuring the inner diameter of the test steel pipe, fluid pressure measurement means for measuring the pressure of the fluid in the pressure chamber, and inner diameter measurement value and fluid measured by the inner diameter measurement means And a calculating means for calculating the crush limit pressure of the crushed test steel pipe based on the pressure measurement value of the fluid measured by the pressure measuring means.
　本発明に係るパイプライン用鋼管の圧潰試験方法、パイプライン用鋼管の製造方法及び圧潰試験装置によれば、加圧流体の作用で試験鋼管が径方向内方に変形する際には試験鋼管の軸方向の両端面に摩擦力が発生せず、パイプライン用鋼管の圧潰限界圧力を試験鋼管で高精度に再現することができる。 According to the crushing test method of a pipeline steel pipe, the manufacturing method of a pipeline steel pipe and the crushing test apparatus according to the present invention, when the test steel pipe is deformed radially inward by the action of the pressurized fluid, No frictional force is generated on both end faces in the axial direction, and the crushing limit pressure of the pipeline steel pipe can be reproduced with high accuracy using the test steel pipe.
本発明に係る第１実施形態のパイプライン用鋼管の圧潰試験装置を示す断面図である。It is sectional drawing which shows the crushing test apparatus of the steel pipe for pipelines of 1st Embodiment which concerns on this invention. 第１実施形態のパイプライン用鋼管の圧潰試験装置の要部を示す図である。It is a figure which shows the principal part of the crushing test apparatus of the steel pipe for pipelines of 1st Embodiment. 第１実施形態のパイプライン用鋼管の圧潰試験装置を構成する演算部の構成を示すブロック図である。It is a block diagram which shows the structure of the calculating part which comprises the crushing test apparatus of the steel pipe for pipelines of 1st Embodiment. 第２実施形態のパイプライン用鋼管の圧潰試験装置の要部を示す図である。It is a figure which shows the principal part of the crushing test apparatus of the steel pipe for pipelines of 2nd Embodiment. 第３実施形態のパイプライン用鋼管の圧潰試験装置の要部を示す図である。It is a figure which shows the principal part of the crushing test apparatus of the steel pipe for pipelines of 3rd Embodiment. 第４実施形態のパイプライン用鋼管の圧潰試験装置の要部を示す図である。It is a figure which shows the principal part of the crushing test apparatus of the steel pipe for pipelines of 4th Embodiment. 圧潰試験を行った際に塑性圧潰を再現した試験鋼管の内径変位を示すグラフである。It is a graph which shows inner diameter displacement of the test steel pipe which reproduced plastic crushing when a crushing test was performed.
　次に、図面を参照して、本発明に係る第１から第３実施形態を説明する。以下の図面の記載において、同一又は類似の部分には同一又は類似の符号を付している。ただし、図面は模式的なものであり、現実のものとは異なることに留意すべきである。したがって、具体的な厚みや寸法は以下の説明を参酌して判断すべきものである。また、図面相互間においても互いの寸法の関係や比率が異なる部分が含まれていることはもちろんである。
　また、以下に示す第１から第４実施形態は、本発明の技術的思想を具体化するための装置や方法を例示するものであって、本発明の技術的思想は、構成部品の材質、形状、構造、配置等を下記のものに特定するものでない。本発明の技術的思想は、特許請求の範囲に記載された請求項が規定する技術的範囲内において、種々の変更を加えることができる。 Next, first to third embodiments according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar reference numerals are given to the same or similar parts. However, it should be noted that the drawings are schematic and different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following description. Further, it is needless to say that the drawings include parts in which dimensional relationships and ratios are different from each other.
Further, the following first to fourth embodiments exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is as follows: The shape, structure, arrangement, etc. are not specified below. Various changes can be added to the technical idea of the present invention within the technical scope defined by the claims described in the claims.
［第１実施形態の圧潰試験装置］
　図１及び図２は、本発明に係る第１実施形態のパイプライン用鋼管の圧潰試験装置を示すものである。
　図１に示すように、第１実施形態のパイプライン用鋼管の圧潰試験装置１は、試験鋼管２と、試験鋼管２の外周に装着した変形体３と、変形体３を軸方向から挟持した状態で試験鋼管２及び変形体３を内部に配置した装置本体４と、加圧水供給部５と、歪み計６と、圧力計７と、演算部８と、を備えている。 [Crush Test Apparatus of First Embodiment]
1 and 2 show a crushing test apparatus for steel pipes for pipelines according to a first embodiment of the present invention.
As shown in FIG. 1, a crushing test apparatus 1 for pipeline steel pipes according to the first embodiment sandwiches a test steel pipe 2, a deformable body 3 mounted on the outer periphery of the test steel pipe 2, and the deformable body 3 from an axial direction. In the state, the apparatus main body 4 in which the test steel pipe 2 and the deformable body 3 are arranged, the pressurized water supply unit 5, the strain gauge 6, the pressure gauge 7, and the arithmetic unit 8 are provided.
　試験鋼管２は、耐圧潰性能の評価及び予測を行うパイプライン用鋼管の一部を切断してリング形状に形成した部材である。パイプライン用鋼管から切断された試験鋼管２は、その軸方向の両端面が平坦面となるように切削されている。
　変形体３は、試験鋼管２の外周に装着されている合成樹脂で形成した円筒形状の部材である。変形体３の合成樹脂としては、例えばＮＣナイロンと呼ばれるナイロン樹脂が挙げられる。変形体３の肉厚は３mm程度に設定されている。また、変形体３の内径は、試験鋼管２の外径寸法と同一寸法として試験鋼管２の外周面に密着するようにしてもよいが、試験鋼管２の外径寸法より５mm程度大きな寸法であっても圧潰試験には大きな影響を与えない。 The test steel pipe 2 is a member formed by cutting a part of a steel pipe for a pipeline for evaluating and predicting crush resistance performance to form a ring shape. The test steel pipe 2 cut from the pipeline steel pipe is cut such that both axial end faces thereof are flat.
The deformable body 3 is a cylindrical member that is attached to the outer circumference of the test steel pipe 2 and is made of synthetic resin. Examples of the synthetic resin of the deformable body 3 include a nylon resin called NC nylon. The thickness of the deformable body 3 is set to about 3 mm. The inner diameter of the deformable body 3 may be the same as the outer diameter dimension of the test steel pipe 2 so as to be in close contact with the outer peripheral surface of the test steel pipe 2, but it is about 5 mm larger than the outer diameter dimension of the test steel pipe 2. However, it does not significantly affect the crush test.
　図２に示すように、変形体３の軸方向長さＬｃ１は、試験鋼管２の軸方向長さＬｔ１に対して長く設定され、変形体３及び試験鋼管２の軸方向長さの差ΔＬ１（Ｌｃ１－Ｌｔ１）は、０．３mm以上５．０mm以内の範囲に設定されている（０．３≦ΔＬ１≦５．０）。 As shown in FIG. 2, the axial length Lc1 of the deformable body 3 is set longer than the axial length Lt1 of the test steel pipe 2, and the difference ΔL1 (in the axial length between the deformable body 3 and the test steel pipe 2). Lc1-Lt1) is set in the range of 0.3 mm to 5.0 mm (0.3≦ΔL1≦5.0).
　装置本体４は、図１に示すように、貫通部１０ａを設けたドーナツ盤形状の底盤１０と、底盤１０と同一の外周形状を有して貫通部１１ａを設けた天盤１１と、底盤１０及び天盤１１の間に同軸に配置された円環形状の中間盤１２と、を備えている。中間盤１２は、底盤１０及び天盤１１の互いに対向する面の外周に設けた環状の段差部１０ｂ，１１ｂに嵌まり込んだ状態で配置されている。図示されていないが、これら段差部１０ｂ，１１ｂの軸方向に沿って延在する段差面及びこれに対面する中間盤１２の内壁面にシール材を挿入できる溝が形成され、それらの溝にゴムパッキンが装着され段差部１０ｂ，１１ｂ及び中間盤１２の間の液密が保持されている。なお、溝の形状、ゴムパッキンの形状は任意に選択でき、たとえば円形断面あるいは矩形断面のゴムパッキンの装着する構造としてもよい。 As shown in FIG. 1, the device main body 4 includes a doughnut-shaped bottom plate 10 having a penetrating part 10a, a top plate 11 having the same outer peripheral shape as the bottom plate 10 and having a penetrating part 11a, and a bottom plate 10. And a ring-shaped intermediate plate 12 arranged coaxially between the roof 11 and the roof 11. The intermediate plate 12 is arranged in a state of being fitted in annular step portions 10b and 11b provided on the outer peripheries of the surfaces of the bottom plate 10 and the top plate 11 facing each other. Although not shown, grooves for inserting a sealing material are formed on the step surfaces extending along the axial direction of the step portions 10b and 11b and the inner wall surface of the intermediate plate 12 facing the step surfaces. A packing is attached to maintain liquid tightness between the step portions 10b and 11b and the intermediate plate 12. The shape of the groove and the shape of the rubber packing can be arbitrarily selected, and for example, the structure may be such that a rubber packing having a circular cross section or a rectangular cross section is mounted.
　装置本体４には、底盤１０の上面１０ｈと、天盤１１の下面１１ｈと、中間盤１２の内周面１２ａとで囲まれたリング形状の試験空間ＳＴが設けられている。この試験空間ＳＴに、底盤１０の上面１０ｈ及び天盤１１の下面１１ｈの間を軸が延在するように試験鋼管２及び変形体３が配置されている。
　そして、装置本体４に複数の第１連結ボルト１４及び第２連結ボルト１５が装着されている。複数の第１連結ボルト１４は、天盤１１及び中間盤１２の外周側の周方向に所定間隔をあけて軸方向に貫通する貫通孔１１ｃ、１２ｃを通過し、底盤１０の周方向に所定間隔をあけて設けたねじ孔１０ｃにねじ部がねじ込まれている。複数の第２ボルト１５は、天盤１１の内周側の周方向に所定間隔をあけて軸方向に貫通する貫通孔１１ｄを通過し、底盤１０の内周側の周方向に所定間隔をあけて設けたねじ孔１０ｄにねじ部がねじ込まれている。 The apparatus main body 4 is provided with a ring-shaped test space ST surrounded by an upper surface 10h of the bottom board 10, a lower surface 11h of the top board 11, and an inner peripheral surface 12a of the intermediate board 12. In this test space ST, the test steel pipe 2 and the deformable body 3 are arranged so that the axis extends between the upper surface 10h of the bottom plate 10 and the lower surface 11h of the top plate 11.
A plurality of first connecting bolts 14 and second connecting bolts 15 are attached to the device body 4. The plurality of first connecting bolts 14 pass through the through holes 11c, 12c which penetrate the axial direction at predetermined intervals in the outer circumferential side of the roof 11 and the intermediate plate 12, and the predetermined intervals in the circumferential direction of the bottom plate 10. The threaded portion is screwed into the threaded hole 10c provided by opening. The plurality of second bolts 15 pass through the through-holes 11d that penetrate through the axial direction in the circumferential direction on the inner circumferential side of the roof 11 at predetermined intervals, and set the predetermined intervals in the circumferential direction on the inner circumferential side of the bottom plate 10. The screw portion is screwed into the screw hole 10d provided as above.
　これら複数の第１及び第２連結ボルト１４，１５を装着することで、変形体３は軸方向の両端面３ａ，３ｂが天盤１１の下面１１ｈ及び底盤１０の上面１０ｈに密着した状態で底盤１０及び天盤１１に挟持される。また、変形体３の外周面、中間盤１２の内周面、天盤１１の下面１１ｈ及び底盤１０の上面１０ｈで囲まれた空間には圧力室１６が形成されている。
　天盤１１には、圧力室１６及び装置本体４の外部に連通する水供給路１１ｅ及び圧力計測路１１ｆが形成されており、水供給路１１ｅには加圧水供給部５が接続され、圧力計測路１１ｆには圧力計７が接続されている。さらに、試験鋼管２の内周面には、複数の歪み計６が装着されている。 By mounting the plurality of first and second connecting bolts 14 and 15, the bottom surface of the deformable body 3 in a state where both end surfaces 3a and 3b in the axial direction are in close contact with the lower surface 11h of the top 11 and the upper surface 10h of the bottom board 10. It is sandwiched between 10 and the roof 11. A pressure chamber 16 is formed in a space surrounded by the outer peripheral surface of the deformable body 3, the inner peripheral surface of the intermediate plate 12, the lower surface 11h of the roof 11 and the upper surface 10h of the bottom plate 10.
A water supply passage 11e and a pressure measurement passage 11f, which communicate with the outside of the pressure chamber 16 and the apparatus body 4, are formed in the roof 11, and the pressurized water supply unit 5 is connected to the water supply passage 11e. The pressure gauge 7 is connected to 11f. Further, a plurality of strain gauges 6 are attached to the inner peripheral surface of the test steel pipe 2.
　演算部８は、図３に示すように、入力部８ａ、圧潰圧力演算部８ｂ及び表示部８ｃなどを備えている。これら入力部８ａ、圧潰圧力演算部８ｂ及び表示部８ｃは、具体的にはパーソナルコンピュータやワークステーション等の汎用の情報処理装置によって実現されるものであり、例えばＣＰＵ、ＲＯＭ、ＲＡＭ等を主要構成部品としているとともに、ネットワークで接続され、データのやり取りが可能に構成されている。 As shown in FIG. 3, the calculation unit 8 includes an input unit 8a, a crushing pressure calculation unit 8b, a display unit 8c, and the like. The input unit 8a, the crushing pressure calculation unit 8b, and the display unit 8c are specifically realized by a general-purpose information processing device such as a personal computer or a workstation, and have, for example, a CPU, a ROM, a RAM, etc. as main components. In addition to being parts, they are connected by a network and are configured to exchange data.
　演算部８の入力部８ａには、圧力計７で計測した圧力室１６の圧力値が入力されるとともに、試験鋼管２の内周面に装着された複数の歪み計６が計測した試験鋼管２の変位量が入力される。
　圧潰圧力演算部８ｂは、入力部８ａに入力した圧力室１６の圧力値変化と、試験鋼管２の変位量に基づいて、試験鋼管２が圧潰したときの圧力（圧潰限界圧力）を演算する。
　表示部８ｃは、圧潰圧力演算部８ｂで演算した試験鋼管２の圧潰限界圧力の値を表示する。 The pressure value of the pressure chamber 16 measured by the pressure gauge 7 is input to the input section 8a of the calculation section 8, and the test steel pipe 2 measured by the plurality of strain gauges 6 mounted on the inner peripheral surface of the test steel pipe 2 is measured. The displacement amount of is input.
The crushing pressure calculation unit 8b calculates the pressure when the test steel pipe 2 is crushed (crushing limit pressure) based on the change in the pressure value of the pressure chamber 16 input to the input unit 8a and the displacement amount of the test steel pipe 2.
The display unit 8c displays the value of the crush limit pressure of the test steel pipe 2 calculated by the crush pressure calculation unit 8b.
　なお、本発明に記載されている一対の対向壁が、天盤１１の下面１１ｈ及び底盤１０の上面１０ｈに対応し、本発明に記載されている流体供給手段が、加圧水供給部５に対応し、本発明に記載されている内径測定手段が、歪み計６に対応し、本発明に記載されている流体圧力測定手段が、圧力計７に対応し、本発明に記載されている演算手段が、演算部８に対応している。 The pair of opposing walls described in the present invention correspond to the lower surface 11h of the top 11 and the upper surface 10h of the bottom board 10, and the fluid supply means described in the present invention corresponds to the pressurized water supply unit 5. The inner diameter measuring means described in the present invention corresponds to the strain gauge 6, the fluid pressure measuring means described in the present invention corresponds to the pressure gauge 7, and the arithmetic means described in the present invention. , Corresponding to the calculation unit 8.
　次に、第１実施形態の圧潰試験装置１を使用したパイプライン用鋼管の圧潰試験手順について作用とともに説明する。
　先ず、試験鋼管２の外周に変形体３を装着する。
　次に、図１に示すように、装置本体４の試験空間ＳＴに、底盤１０の上面１０ｈ及び天盤１１の下面１１ｈの間を軸が延在するように試験鋼管２及び変形体３を配置する。
　次に、装置本体４に複数の第１連結ボルト１４及び第２連結ボルト１５を装着し、変形体３の軸方向の両端面３ａ，３ｂを天盤１１の下面１１ｈ及び底盤１０の上面１０ｈに密着した状態で、変形体３を底盤１０及び天盤１１で挟持する。これにより、変形体３の外周面、中間盤１２の内周面、天盤１１の下面１１ｈ及び底盤１０の上面１０ｈで囲まれた空間に圧力室１６が形成される。 Next, a crushing test procedure for a steel pipe for a pipeline using the crushing test apparatus 1 of the first embodiment will be described together with its operation.
First, the deformable body 3 is attached to the outer circumference of the test steel pipe 2.
Next, as shown in FIG. 1, the test steel pipe 2 and the deformable body 3 are arranged in the test space ST of the apparatus main body 4 so that the axis extends between the upper surface 10h of the bottom plate 10 and the lower surface 11h of the top plate 11. To do.
Next, the plurality of first connecting bolts 14 and the second connecting bolts 15 are attached to the apparatus body 4, and both axial end surfaces 3a and 3b of the deformable body 3 are attached to the lower surface 11h of the roof 11 and the upper surface 10h of the bottom board 10. The deformable body 3 is sandwiched between the bottom plate 10 and the top plate 11 in a state of being in close contact with each other. As a result, the pressure chamber 16 is formed in the space surrounded by the outer peripheral surface of the deformable body 3, the inner peripheral surface of the intermediate plate 12, the lower surface 11h of the top 11 and the upper surface 10h of the bottom plate 10.
　このとき、図２に示すように、試験鋼管２は、軸方向の一方の端面２ｂが底盤１０の上面１０ｈに載置され、軸方向の他方の端面２ａが天盤１１の下面１１ｈには接触しない状態で、変形体３の内側に配置される。
　次に、加圧水供給部５から水供給路１１ｅを介して圧力室１６に加圧水を供給していく。加圧水供給部５からの加圧水の供給によって圧力室１６の水圧が上昇していくと、水圧が変形体３の外周面に作用して変形体３が径方向内方に塑性変形していく。変形体３の塑性変形とともに、変形体３の内側に装着した試験鋼管２も径方向内方に塑性変形していく。 At this time, as shown in FIG. 2, in the test steel pipe 2, one end surface 2b in the axial direction is placed on the upper surface 10h of the bottom plate 10 and the other end surface 2a in the axial direction contacts the lower surface 11h of the roof 11. It is arranged inside the deformable body 3 in a state where it is not.
Next, the pressurized water is supplied from the pressurized water supply unit 5 to the pressure chamber 16 via the water supply passage 11e. When the water pressure in the pressure chamber 16 is increased by the supply of the pressurized water from the pressurized water supply unit 5, the water pressure acts on the outer peripheral surface of the deformable body 3 and the deformable body 3 is plastically deformed radially inward. With the plastic deformation of the deformable body 3, the test steel pipe 2 mounted inside the deformable body 3 also plastically deforms radially inward.
　変形体３は合成樹脂で形成されているので、天盤１１の下面１１ｈ及び底盤１０の上面１０ｈに密着していても、下面１１ｈ及び上面１０ｈとの間に大きな摩擦力が発生しない。
　試験鋼管２は、変形体３を介して圧力室１６の水圧が外周に作用するので、同様に径方向内方に塑性変形していく。このとき、試験鋼管２は、軸方向の一方の端面２ｂが底盤１０の上面１０ｈに載置され、軸方向の他方の端面２ａが天盤１１の下面１１ｈには接触しておらず、底盤１０及び天盤１１に挟持されていないので、軸方向の端面２ａ，２ｂは下面１１ｈ及び上面１０ｈとの間に摩擦力が発生しない。 Since the deformable body 3 is made of synthetic resin, even if the deformable body 3 is in close contact with the lower surface 11h of the roof 11 and the upper surface 10h of the bottom board 10, a large frictional force is not generated between the lower surface 11h and the upper surface 10h.
Since the water pressure of the pressure chamber 16 acts on the outer circumference of the test steel pipe 2 via the deformable body 3, the test steel pipe 2 is likewise plastically deformed radially inward. At this time, in the test steel pipe 2, one end surface 2b in the axial direction is placed on the upper surface 10h of the bottom plate 10 and the other end surface 2a in the axial direction is not in contact with the lower surface 11h of the roof 11, so that the bottom plate 10 is not in contact. Since it is not sandwiched between the roof 11 and the roof 11, frictional force is not generated between the axial end surfaces 2a and 2b and the lower surface 11h and the upper surface 10h.
　そして、演算部８は、入力部８ａに試験鋼管２の外周に作用する圧力室１６の水圧の圧力値が圧力計７から入力し、径方向内方に塑性変形する試験鋼管２の変位量が複数の歪み計６から入力するので、圧潰圧力演算部８ｂは、圧力室１６の圧力値変化と、試験鋼管２の変位量に基づいて、試験鋼管２が圧潰したときの圧潰限界圧力を演算する。そして、表示部８ｃが、試験鋼管２の圧潰限界圧力の値を表示する。
　ここで、径方向内方に塑性変形する試験鋼管２は、軸長が増大する方向にも塑性変形していく。本実施形態は、変形体３の軸方向長さＬｃ１と試験鋼管２の軸方向長さＬｔ１の差ΔＬ１を０．３mm以上に設定しているが、この差ΔＬ１（０．３mm以上）は、軸長が増大する方向に試験鋼管２が塑性変形しても、試験鋼管２の軸方向の端面が天盤１１の下面１１ｈに接触しない値である。これにより、軸長が増大する方向に試験鋼管２が塑性変形しても、天盤１１及び底盤１０との間に摩擦力が発生するおそれがない。 Then, the calculation unit 8 inputs the pressure value of the water pressure of the pressure chamber 16 acting on the outer circumference of the test steel pipe 2 to the input unit 8a from the pressure gauge 7, and the displacement amount of the test steel pipe 2 plastically deformed radially inward. Since input is made from a plurality of strain gauges 6, the crush pressure calculation unit 8b calculates the crush limit pressure when the test steel pipe 2 is crushed based on the change in the pressure value of the pressure chamber 16 and the displacement amount of the test steel pipe 2. .. Then, the display unit 8c displays the value of the crushing limit pressure of the test steel pipe 2.
Here, the test steel pipe 2 which is plastically deformed radially inward is also plastically deformed in the direction in which the axial length increases. In the present embodiment, the difference ΔL1 between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is set to 0.3 mm or more, but this difference ΔL1 (0.3 mm or more) is Even if the test steel pipe 2 is plastically deformed in the direction in which the axial length increases, the axial end surface of the test steel pipe 2 does not come into contact with the lower surface 11h of the roof 11. As a result, even if the test steel pipe 2 is plastically deformed in the direction in which the axial length increases, there is no possibility of generating a frictional force between the top plate 11 and the bottom plate 10.
　なお、変形体３の軸方向長さＬｃ１と試験鋼管２の軸方向長さＬｔ１の差ΔＬ１が０．３mmを下回ると、試験鋼管２の端面が天盤１１の下面１１ｈに接触するので、試験鋼管２と天盤１１及び底盤１０との間に摩擦力が発生するおそれがある。
　また、変形体３の軸方向長さＬｃ１と試験鋼管２の軸方向長さＬｔ１の差ΔＬ１が大きすぎると、圧力室１６の水圧の作用により変形体３が過度に変形してしまい、変形体３の軸方向の端面３ａ及び天盤１１の下面１１ｈの接触位置と、変形体３の軸方向の端面３ｂ及び底盤１０の上面１０ｈの接触位置の液密性が低下するおそれがある。そこで、第１実施形態では、差ΔＬ１を５．０mm以下の値に設定することで、変形体３の過度の変形を防止して底盤１０及び天盤１１と変形体３との接触位置の液密性を確保している。 If the difference ΔL1 between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is less than 0.3 mm, the end surface of the test steel pipe 2 comes into contact with the lower surface 11h of the roof 11, so the test A frictional force may be generated between the steel pipe 2 and the top 11 and the bottom 10.
Further, if the difference ΔL1 between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is too large, the deformable body 3 is excessively deformed by the action of water pressure in the pressure chamber 16, and the deformable body is deformed. The liquid-tightness of the contact position between the axial end surface 3a of 3 and the lower surface 11h of the roof 11 and the contact position between the axial end surface 3b of the deformable body 3 and the upper surface 10h of the bottom plate 10 may deteriorate. Therefore, in the first embodiment, by setting the difference ΔL1 to a value of 5.0 mm or less, excessive deformation of the deformable body 3 is prevented, and the liquid at the contact position between the bottom board 10 and the roof 11 and the deformable body 3 is prevented. The tightness is secured.
　次に、第１実施形態のパイプライン用鋼管の圧潰試験装置１の効果について説明する。
　第１実施形態によると、圧潰試験を行う試験鋼管２の外周面に水圧を作用する圧力室１６は、試験鋼管２の外周に装着した変形体３の外周面、中間盤１２の内周面、天盤１１の下面１１ｈ及び底盤１０の上面１０ｈで囲まれた空間で形成されている。そして、試験鋼管２には、変形体３を介して圧力室１６の水圧が作用して径方向内方に塑性変形していくが、この試験鋼管２は、軸方向の一方の端面２ｂが底盤１０の上面１０ｈに載り、軸方向の他方の端面２ａが天盤１１の下面１１ｈには接触しておらず、軸方向の端面２ａ，２ｂは下面１１ｈ及び上面１０ｈとの間に摩擦力が発生しない。 Next, effects of the crushing test apparatus 1 for a steel pipe for a pipeline according to the first embodiment will be described.
According to the first embodiment, the pressure chamber 16 that applies water pressure to the outer peripheral surface of the test steel pipe 2 to be subjected to the crush test includes the outer peripheral surface of the deformable body 3 mounted on the outer peripheral surface of the test steel pipe 2, the inner peripheral surface of the intermediate plate 12, It is formed in a space surrounded by a lower surface 11h of the top 11 and an upper surface 10h of the bottom 10. Then, the water pressure of the pressure chamber 16 acts on the test steel pipe 2 via the deformable body 3 and plastically deforms inward in the radial direction. However, in this test steel pipe 2, one end surface 2b in the axial direction is the bottom plate. 10, the other axial end surface 2a is not in contact with the lower surface 11h of the roof 11, and the axial end surfaces 2a and 2b generate a frictional force between the lower surface 11h and the upper surface 10h. do not do.
　したがって、圧潰試験を行う試験鋼管２に摩擦力が発生しないので、パイプライン用鋼管の圧潰限界圧力を試験鋼管２で高精度に再現することができ、パイプライン用鋼管の耐圧潰性能を高精度に評価することができる。
　また、変形体３の軸方向長さＬｃ１と試験鋼管２の軸方向長さＬｔ１との差ΔＬ１（Ｌｃ１－Ｌｔ１）を０．３mm以上に設定しているので、試験鋼管２が軸長が増大する方向に塑性変形しても、天盤１１の下面１１ｈに接触せず天盤１１との間に摩擦力が発生せず、パイプライン用鋼管の耐圧潰性能の評価をさらに高精度に行うことができる。
　また、変形体３の軸方向長さＬｃ１と試験鋼管２の軸方向長さＬｔ１との差ΔＬ１（Ｌｃ１－Ｌｔ１）を、５．０mm以下の値に設定することで、圧力室１６の液密性を十分に確保することができるので、さらに、試験鋼管２の圧潰限界圧力を高精度に演算することができる。 Therefore, since no frictional force is generated in the test steel pipe 2 to be subjected to the crushing test, the crushing limit pressure of the pipeline steel pipe can be reproduced with high accuracy in the test steel pipe 2, and the pressure crushing performance of the pipeline steel pipe is highly accurate. Can be evaluated.
Further, since the difference ΔL1 (Lc1-Lt1) between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is set to 0.3 mm or more, the test steel pipe 2 has an increased axial length. Even if it is plastically deformed in the direction in which it does not contact the lower surface 11h of the roof 11 and no frictional force is generated between it and the roof 11, the pressure crushing performance of the pipeline steel pipe can be evaluated with higher accuracy. You can
Further, by setting the difference ΔL1 (Lc1-Lt1) between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 to a value of 5.0 mm or less, the liquid tightness of the pressure chamber 16 can be improved. Since it is possible to sufficiently secure the property, the crushing limit pressure of the test steel pipe 2 can be calculated with high accuracy.
［第２実施形態の圧潰試験装置］
　次に、図４は、本発明に係る第２実施形態のパイプライン用鋼管の圧潰試験装置１７の要部を示すものである。なお、第１実施形態のパイプライン用鋼管の圧潰試験装置１で示した構成要件と同一構成部分には、同一符号を付して説明は省略する。
　本実施形態の圧潰試験装置１７の装置本体４は、第１実施形態で示した段差部１０ｂ，１１ｂの軸方向に沿う段差面及びこれに対面する中間盤１２の内壁面にリング溝が形成されておらず、代わりに、段差部１０ｂ，１１ｂの軸方向に直交する段差面及びこれに対面する中間盤１２の軸方向の面に断面四角形状のリング溝が形成されている。そして、段差部１０ｂ，１１ｂ及び中間盤１２の軸方向で対面する面に形成したリング溝に矩形断面の環状パッキン２３が装着されている。 [Crush Test Apparatus of Second Embodiment]
Next, FIG. 4 shows a main part of a crushing test apparatus 17 for pipeline steel pipes according to a second embodiment of the present invention. The same components as those of the crushing test apparatus 1 for a steel pipe for a pipeline according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
In the device body 4 of the crushing test device 17 of the present embodiment, ring grooves are formed on the step surfaces along the axial direction of the step portions 10b and 11b shown in the first embodiment and on the inner wall surface of the intermediate plate 12 facing the step surfaces. Instead, instead, a ring groove having a quadrangular cross section is formed on the step surfaces orthogonal to the axial direction of the step portions 10b and 11b and the axial surface of the intermediate disk 12 facing the step surfaces. An annular packing 23 having a rectangular cross section is attached to the ring grooves formed on the surfaces of the step portions 10b and 11b and the intermediate plate 12 that face each other in the axial direction.
　第２実施形態によると、天盤１１を貫通して底盤１０にねじ込まれることで第１及び第２連結ボルト１４，１５に発生する軸力が、段差部１０ｂ，１１ｂの軸方向に直交する段差面及びこれに対面する中間盤１２の軸方向に直交する面の間に装着されている環状パッキン２３に大きな密着力を作用するので、第１実施形態と比較して、圧力室１６の水圧を大幅に高めることが可能となる。
　したがって、第２実施形態のパイプライン用鋼管の圧潰試験装置１７は、第１実施形態の圧潰試験装置１と比較して圧力室１６の水圧を大幅に高めて試験鋼管２の圧潰限界圧力を測定することができるので、パイプライン用鋼管の大幅に高い値の圧潰限界圧力を試験鋼管２で高精度に再現することができる。 According to the second embodiment, the axial force generated in the first and second connecting bolts 14 and 15 by passing through the roof 11 and being screwed into the bottom plate 10 causes a step difference perpendicular to the axial direction of the step parts 10b and 11b. Since a large adhesion force acts on the annular packing 23 mounted between the surface and the surface of the intermediate plate 12 facing the surface and orthogonal to the axial direction, the water pressure in the pressure chamber 16 is increased as compared with the first embodiment. It is possible to greatly increase it.
Therefore, the crushing test apparatus 17 for steel pipes for pipelines of the second embodiment measures the crushing limit pressure of the test steel tube 2 by significantly increasing the water pressure of the pressure chamber 16 as compared with the crushing test apparatus 1 of the first embodiment. Therefore, the crushing limit pressure of a significantly high value of the pipeline steel pipe can be reproduced with high accuracy in the test steel pipe 2.
　なお、第２実施形態では段差部１０ｂ，１１ｂの軸方向に直交する段差面及びこれに対面する中間盤１２の軸方向に直交する面に設けたリング溝に環状パッキン２３を装着したが、断面円弧形状のリング溝を形成し、このリング溝にＯリングを装着しても、同様の効果を奏することができる。 In the second embodiment, the annular packing 23 is attached to the ring groove provided on the step surface orthogonal to the axial direction of the step portions 10b and 11b and the surface orthogonal to the axial direction of the intermediate plate 12 facing the step surface. Even if an arc-shaped ring groove is formed and an O-ring is attached to this ring groove, the same effect can be obtained.
［第３実施形態の圧潰試験装置］
　次に、図５は、本発明に係る第３実施形態のパイプライン用鋼管の圧潰試験装置の要部を示すものである。なお、第１実施形態のパイプライン用鋼管の圧潰試験装置で示した構成要件と同一構成部分には、同一符号を付して説明は省略する。
　第３実施形態の圧潰試験装置２０は、変形体３の外周に、円筒形状のゴムパッキン２１が装着されている。 [Crush Test Apparatus of Third Embodiment]
Next, FIG. 5 shows a main part of a crushing test apparatus for steel pipes for pipelines according to a third embodiment of the present invention. The same components as those of the crushing test device for pipeline steel pipes according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
In the crushing test device 20 of the third embodiment, a cylindrical rubber packing 21 is attached to the outer periphery of the deformable body 3.
　ゴムパッキン２１は、軸方向の両端に肉厚部２１ａ，２１ｂを設けており、肉厚部２１ａ，２１ｂ以外の厚さが３mmとした部材であり、自由長のときの軸方向長さが、変形体３の軸方向長さＬｃ２より長く設定されている。また、肉厚部２１ａ，２１ｂは必ずしも必要ではなく、肉厚部がなくても本発明の効果を発揮できる。
　また、変形体３の軸方向長さＬｃ２は、試験鋼管２の軸方向長さＬｔ２に対して長く設定され、変形体３及び試験鋼管２の軸方向長さの差ΔＬ２（Ｌｃ２－Ｌｔ２）は、１．０mm以上１．３mm以内の範囲に設定されている（１．０≦ΔＬ２≦１．３）。
　なお、本発明に記載されている円筒形状の弾性体が、ゴムパッキン２１に対応している。 The rubber packing 21 is a member in which thick portions 21a and 21b are provided at both ends in the axial direction, and the thickness other than the thick portions 21a and 21b is 3 mm, and the axial length in the free length is It is set to be longer than the axial length Lc2 of the deformable body 3. Further, the thick portions 21a and 21b are not always necessary, and the effect of the present invention can be exhibited without the thick portions.
Further, the axial length Lc2 of the deformable body 3 is set longer than the axial length Lt2 of the test steel pipe 2, and the difference ΔL2 (Lc2-Lt2) between the axial lengths of the deformable body 3 and the test steel pipe 2 is , 1.0 mm or more and 1.3 mm or less (1.0≦ΔL2≦1.3).
The cylindrical elastic body described in the present invention corresponds to the rubber packing 21.
　次に、第３実施形態の圧潰試験装置２０を使用したパイプライン用鋼管の圧潰試験手順について作用とともに説明する。
　先ず、試験鋼管２の外周に変形体３を装着し、変形体３の外周にゴムパッキン２１を装着する。
　次に、装置本体４の試験空間ＳＴに、底盤１０の上面１０ｈ及び天盤１１の下面１１ｈの間を軸が延在するように試験鋼管２、変形体３及びゴムパッキン２１を配置する。 Next, a crushing test procedure of a steel pipe for a pipeline using the crushing test device 20 of the third embodiment will be described together with its operation.
First, the deformable body 3 is attached to the outer periphery of the test steel pipe 2, and the rubber packing 21 is attached to the outer periphery of the deformable body 3.
Next, in the test space ST of the apparatus body 4, the test steel pipe 2, the deformable body 3, and the rubber packing 21 are arranged so that the axis extends between the upper surface 10h of the bottom plate 10 and the lower surface 11h of the roof 11.
　次に、装置本体４に複数の第１連結ボルト１４及び第２連結ボルト１５を装着し、変形体３の軸方向の両端面３ａ，３ｂを天盤１１の下面１１ｈ及び底盤１０の上面１０ｈに密着し、ゴムパッキン２１の軸方向の両端の肉厚部２１ａ，２１ｂを圧縮状態で弾性変形させて、変形体３を底盤１０及び天盤１１で挟持する。これにより、ゴムパッキン２１の外周面、中間盤１２の内周面、天盤１１の下面１１ｈ及び底盤１０の上面１０ｈで囲まれた空間に圧力室１６が形成される。
　このとき、試験鋼管２は、軸方向の一方の端面２ｂが底盤１０の上面１０ｈに載置され、軸方向の他方の端面２ａが天盤１１の下面１１ｈには接触しない状態で、変形体３の内側に配置される。 Next, the plurality of first connecting bolts 14 and the second connecting bolts 15 are attached to the apparatus body 4, and both axial end surfaces 3a and 3b of the deformable body 3 are attached to the lower surface 11h of the roof 11 and the upper surface 10h of the bottom board 10. The thickened portions 21a and 21b at both ends of the rubber packing 21 in the axial direction are elastically deformed in a compressed state so as to sandwich the deformable body 3 between the bottom plate 10 and the top plate 11. As a result, the pressure chamber 16 is formed in a space surrounded by the outer peripheral surface of the rubber packing 21, the inner peripheral surface of the intermediate plate 12, the lower surface 11h of the top 11 and the upper surface 10h of the bottom plate 10.
At this time, in the test steel pipe 2, one end surface 2b in the axial direction is placed on the upper surface 10h of the bottom plate 10 and the other end surface 2a in the axial direction does not contact the lower surface 11h of the roof 11, and the deformable body 3 is deformed. Placed inside.
　次に、加圧水供給部５から水供給路１１ｅを介して圧力室１６に加圧水を供給していく。加圧水供給部５からの加圧水の供給によって圧力室１６の水圧が上昇していくと、水圧がゴムパッキン２１を介して変形体３の外周面に作用し、変形体３が径方向内方に塑性変形していく。そして、変形体３の塑性変形とともに、変形体３の内側に装着した試験鋼管２も径方向内方に塑性変形していく。
　径方向内方に塑性変形する試験鋼管２は、軸方向の一方の端面２ｂが底盤１０の上面１０ｈに載置され、軸方向の他方の端面２ａが天盤１１の下面１１ｈには接触しておらず、底盤１０及び天盤１１に挟持されていないので、軸方向の端面２ａ，２ｂは下面１１ｈ及び上面１０ｈとの間に摩擦力が発生しない。 Next, the pressurized water is supplied from the pressurized water supply unit 5 to the pressure chamber 16 via the water supply passage 11e. When the water pressure in the pressure chamber 16 increases due to the supply of the pressurized water from the pressurized water supply unit 5, the water pressure acts on the outer peripheral surface of the deformable body 3 via the rubber packing 21, and the deformable body 3 is plastically deformed radially inward. It transforms. Then, along with the plastic deformation of the deformable body 3, the test steel pipe 2 mounted inside the deformable body 3 also plastically deforms radially inward.
In the test steel pipe 2 which is plastically deformed inward in the radial direction, one end face 2b in the axial direction is placed on the upper face 10h of the bottom plate 10, and the other end face 2a in the axial direction contacts the lower face 11h of the roof 11. Since it is not sandwiched between the bottom plate 10 and the top plate 11, no frictional force is generated between the axial end faces 2a and 2b and the lower face 11h and the upper face 10h.
　試験鋼管２は、径方向内方への塑性変形とともに、軸長が増大する方向にも塑性変形していく。第２実施形態は、変形体３の軸方向長さＬｃ２と試験鋼管２の軸方向長さＬｔ２の差ΔＬ１を１．０mm以上に設定しているが、この差ΔＬ２（１．０mm以上）は、軸長が増大する方向に試験鋼管２が塑性変形しても、試験鋼管２の軸方向の端面が天盤１１の下面１１ｈに接触しない値である。これにより、軸長が増大する方向に試験鋼管２が塑性変形しても、天盤１１及び底盤１０との間に摩擦力が発生するおそれがない。
　また、第３実施形態では、差ΔＬ２を１．３mm以下の値に設定することで、変形体３の過度の変形を防止して底盤１０及び天盤１１と変形体３との接触位置の液密性を確保している。 The test steel pipe 2 is plastically deformed inward in the radial direction and is also plastically deformed in a direction in which the axial length is increased. In the second embodiment, the difference ΔL1 between the axial length Lc2 of the deformable body 3 and the axial length Lt2 of the test steel pipe 2 is set to 1.0 mm or more, but this difference ΔL2 (1.0 mm or more) is set. Even if the test steel pipe 2 is plastically deformed in the direction in which the axial length increases, the axial end surface of the test steel pipe 2 does not come into contact with the lower surface 11h of the roof 11. As a result, even if the test steel pipe 2 is plastically deformed in the direction in which the axial length increases, there is no possibility of generating a frictional force between the top plate 11 and the bottom plate 10.
Further, in the third embodiment, by setting the difference ΔL2 to a value of 1.3 mm or less, excessive deformation of the deformable body 3 is prevented, and the liquid at the contact position between the bottom plate 10 and the roof 11 and the deformable body 3 is prevented. The tightness is secured.
　次に、第３実施形態のパイプライン用鋼管の圧潰試験装置２０の効果について説明する。
　試験鋼管２には変形体３を介して圧力室１６の水圧が作用して径方向内方に塑性変形していくが、試験鋼管２は、軸方向の一方の端面２ｂが底盤１０の上面１０ｈに載り、軸方向の他方の端面２ａが天盤１１の下面１１ｈには接触しておらず、軸方向の端面２ａ，２ｂは下面１１ｈ及び上面１０ｈとの間に摩擦力が発生しない。したがって、圧潰試験を行う試験鋼管２に摩擦力が発生しないので、パイプライン用鋼管の圧潰限界圧力を試験鋼管２で高精度に再現することができ、パイプライン用鋼管の耐圧潰性能を高精度に評価することができる。 Next, the effect of the steel pipe crushing test apparatus 20 of the third embodiment will be described.
The water pressure of the pressure chamber 16 acts on the test steel pipe 2 via the deformable body 3 and plastically deforms inward in the radial direction. However, in the test steel pipe 2, one end face 2b in the axial direction is the top face 10h of the bottom plate 10h. The other end surface 2a in the axial direction is not in contact with the lower surface 11h of the roof 11, and the axial end surfaces 2a and 2b do not generate frictional force between the lower surface 11h and the upper surface 10h. Therefore, since no frictional force is generated in the test steel pipe 2 to be subjected to the crushing test, the crushing limit pressure of the pipeline steel pipe can be reproduced with high accuracy in the test steel pipe 2, and the pressure crushing performance of the pipeline steel pipe is highly accurate. Can be evaluated.
　また、第３実施形態の圧潰試験装置２０は、変形体３の外周にゴムパッキン２１が装着され、変形体３を底盤１０及び天盤１１で挟持する際には、ゴムパッキン２１の軸方向の両端の肉厚部２１ａ，２１ｂが天盤１１の下面１１ｈ及び底盤１０の上面１０ｈに圧縮状態で弾性変形している。これにより、第３実施形態の圧潰試験装置２０は、第１実施形態の圧潰試験装置１と比較して、底盤１０及び天盤１１と変形体３との接触位置の液密性が高まるので、圧力室１６の水圧を高めることが可能となる。したがって、第３実施形態の圧潰試験装置２０は、圧力室１６の水圧を高めることで試験鋼管２の高い値の圧潰限界圧力を測定することができ、パイプライン用鋼管の高い値の圧潰限界圧力を試験鋼管で高精度に再現することができる。 Further, in the crushing test apparatus 20 of the third embodiment, the rubber packing 21 is attached to the outer periphery of the deformable body 3, and when the deformable body 3 is sandwiched between the bottom plate 10 and the top plate 11, the rubber packing 21 moves in the axial direction of the rubber packing 21. The thick portions 21a and 21b at both ends are elastically deformed in a compressed state on the lower surface 11h of the top board 11 and the upper surface 10h of the bottom board 10. Thereby, the crushing test apparatus 20 of the third embodiment has higher liquid-tightness at the contact position between the bottom plate 10 and the roof 11 and the deformable body 3, as compared with the crushing test apparatus 1 of the first embodiment. The water pressure in the pressure chamber 16 can be increased. Therefore, the crushing test apparatus 20 of the third embodiment can measure the high value of the crushing limit pressure of the test steel pipe 2 by increasing the water pressure in the pressure chamber 16, and the high value of the crushing limit pressure of the pipeline steel pipe can be measured. Can be reproduced with high precision using a test steel pipe.
　また、変形体３の軸方向長さＬｃ２と試験鋼管２の軸方向長さＬｔ２との差ΔＬ２（Ｌｃ２－Ｌｔ２）を１．０≦ΔＬ２≦１．３に設定しているので、試験鋼管２が軸長が増大する方向に塑性変形しても、天盤１１の下面１１ｈに接触せず天盤１１との間に摩擦力が発生せず、パイプライン用鋼管の耐圧潰性能の評価をさらに高精度に行うことができるとともに、試験鋼管２の圧潰限界圧力を高精度に演算することができる。 Further, since the difference ΔL2 (Lc2-Lt2) between the axial length Lc2 of the deformable body 3 and the axial length Lt2 of the test steel pipe 2 is set to 1.0≦ΔL2≦1.3, the test steel pipe 2 Even if is plastically deformed in the direction of increasing the axial length, the lower surface 11h of the roof 11 does not come into contact with the roof 11 and no frictional force is generated between the roof 11 and the pressure crushing performance of the pipeline steel pipe. It can be performed with high accuracy, and the crush limit pressure of the test steel pipe 2 can be calculated with high accuracy.
［第４実施形態の圧潰試験装置］
　次に、図６は、本発明に係る第４実施形態のパイプライン用鋼管の圧潰試験装置の要部を示すものである。なお、図５で示した第３実施形態のパイプライン用鋼管の圧潰試験装置２０で示した構成要件と同一構成部分には、同一符号を付して説明は省略する。
　第４実施形態の圧潰試験装置３０は、変形体３の軸方向の両端面３ａ，３ｂの外周側に、環状の切り欠き３ｃ、３ｄが形成されており、それら切り欠き３ｃ，３ｄに、Ｏリング３１，３２が装着されている。 [Crush Test Apparatus of Fourth Embodiment]
Next, FIG. 6 shows an essential part of a crushing test apparatus for pipeline steel pipes according to a fourth embodiment of the present invention. The same components as those of the crushing test apparatus 20 for pipeline steel pipes according to the third embodiment shown in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.
In the crushing test device 30 of the fourth embodiment, annular notches 3c and 3d are formed on the outer peripheral sides of the axially opposite end faces 3a and 3b of the deformable body 3, and the notches 3c and 3d have O Rings 31 and 32 are attached.
　また、図６では記載していないが、変形体３の軸方向長さＬｃ２と試験鋼管２の軸方向長さＬｔ２との差ΔＬ２（Ｌｃ２－Ｌｔ２）は、１．０≦ΔＬ２≦１．３に設定されている。
　なお、本発明に記載されている環状の凹部が、環状の切り欠き３ｃ、３ｄに対応し、本発明に記載されているＯリングが、Ｏリング３１，３２に対応している。 Although not shown in FIG. 6, the difference ΔL2 (Lc2-Lt2) between the axial length Lc2 of the deformable body 3 and the axial length Lt2 of the test steel pipe 2 is 1.0≦ΔL2≦1.3. Is set to.
The annular recesses described in the present invention correspond to the annular notches 3c and 3d, and the O-rings described in the present invention correspond to the O- rings 31 and 32.
　第４実施形態の圧潰試験装置３０は、試験鋼管２の外周に変形体３を装着し、変形体３の両端面３ａ，３ｂに設けた環状の切り欠き３ｃ、３ｄに、Ｏリング３１，３２を装着する。そして、装置本体４の試験空間ＳＴに、底盤１０の上面１０ｈ及び天盤１１の下面１１ｈの間を軸が延在するように試験鋼管２及びＯリング３１，３２を装着した変形体３を配置する。 In the crush test apparatus 30 of the fourth embodiment, the deformable body 3 is mounted on the outer circumference of the test steel pipe 2, and the O- rings 31, 32 are provided in the annular cutouts 3c, 3d provided on both end faces 3a, 3b of the deformable body 3. Put on. Then, in the test space ST of the apparatus body 4, the deformable body 3 in which the test steel pipe 2 and the O- rings 31, 32 are mounted is arranged so that the axis extends between the upper surface 10h of the bottom plate 10 and the lower surface 11h of the top plate 11. To do.
　また、装置本体４に複数の第１連結ボルト１４及び第２連結ボルト１５を装着し、変形体３の軸方向の両端面３ａ，３ｂを天盤１１の下面１１ｈ及び底盤１０の上面１０ｈに密着し、Ｏリング３１，３２を下面１１ｈ及び上面１０ｈに圧縮状態で弾性変形させて、変形体３を底盤１０及び天盤１１で挟持する。これにより、変形体３の外周面、中間盤１２の内周面、天盤１１の下面１１ｈ及び底盤１０の上面１０ｈで囲まれた空間に圧力室１６が形成される。このとき、試験鋼管２は、軸方向の一方の端面２ｂが底盤１０の上面１０ｈに載置され、軸方向の他方の端面２ａが天盤１１の下面１１ｈには接触しない状態で、変形体３の内側に配置される。 In addition, a plurality of first connecting bolts 14 and second connecting bolts 15 are attached to the device body 4, and both axial end faces 3a and 3b of the deformable body 3 are closely attached to the lower surface 11h of the roof 11 and the upper surface 10h of the bottom board 10. Then, the O- rings 31 and 32 are elastically deformed to the lower surface 11h and the upper surface 10h in a compressed state, and the deformable body 3 is sandwiched between the bottom plate 10 and the top plate 11. As a result, the pressure chamber 16 is formed in the space surrounded by the outer peripheral surface of the deformable body 3, the inner peripheral surface of the intermediate plate 12, the lower surface 11h of the top 11 and the upper surface 10h of the bottom plate 10. At this time, in the test steel pipe 2, one end surface 2b in the axial direction is placed on the upper surface 10h of the bottom plate 10 and the other end surface 2a in the axial direction does not contact the lower surface 11h of the roof 11, and the deformable body 3 is deformed. Placed inside.
　そして、第２実施形態の圧潰試験装置２０と同様に、加圧水供給部５から水供給路１１ｅを介して圧力室１６に加圧水を供給していくと、変形体３の塑性変形とともに、変形体３の内側に装着した試験鋼管２も径方向内方に塑性変形していく。
　したがって、第４実施形態の圧潰試験装置３０も、圧潰試験を行う試験鋼管２に摩擦力が発生しないので、パイプライン用鋼管の圧潰限界圧力を試験鋼管２で高精度に再現することができ、パイプライン用鋼管の耐圧潰性能を高精度に評価することができる。 Then, similarly to the crushing test apparatus 20 of the second embodiment, when pressurized water is supplied from the pressurized water supply unit 5 to the pressure chamber 16 via the water supply passage 11e, the deformable body 3 is plastically deformed and the deformable body 3 is deformed. The test steel pipe 2 mounted on the inside of the plastic also plastically deforms inward in the radial direction.
Therefore, also in the crushing test apparatus 30 of the fourth embodiment, no frictional force is generated in the test steel pipe 2 on which the crushing test is performed, so that the crushing limit pressure of the pipeline steel pipe can be reproduced with high accuracy in the test steel pipe 2, It is possible to highly accurately evaluate the pressure crushing performance of a steel pipe for a pipeline.
　また、第４実施形態の圧潰試験装置３０は、変形体３の両端面３ａ，３ｂ側にＯリング３１，３２が装着され、変形体３を底盤１０及び天盤１１で挟持する際には、Ｏリング３１，３２が天盤１１の下面１１ｈ及び底盤１０の上面１０ｈに圧縮状態で弾性変形している。これにより、第４実施形態の圧潰試験装置３０も、第１実施形態の圧潰試験装置１と比較して、底盤１０及び天盤１１と変形体３との接触位置の液密性が高まるので、圧力室１６の水圧を高めることが可能となる。 Further, in the crushing test device 30 of the fourth embodiment, the O- rings 31 and 32 are attached to both end surfaces 3a and 3b of the deformable body 3, and when the deformable body 3 is sandwiched between the bottom plate 10 and the top plate 11, The O- rings 31 and 32 are elastically deformed on the lower surface 11h of the top 11 and the upper surface 10h of the bottom 10 in a compressed state. Thereby, the crushing test apparatus 30 of the fourth embodiment also has higher liquid-tightness at the contact position between the bottom plate 10 and the roof 11 and the deformable body 3, as compared with the crushing test apparatus 1 of the first embodiment. The water pressure in the pressure chamber 16 can be increased.
　したがって、第４実施形態の圧潰試験装置３０は、圧力室１６の水圧を高めることで試験鋼管２の高い値の圧潰限界圧力を測定することができ、パイプライン用鋼管の高い値の圧潰限界圧力を試験鋼管で高精度に再現することができる。
　また、第１～第４実施形態の圧潰試験装置１，１７，２０，３０を使用して圧潰試験を行うことで、高精度の圧潰限界圧力が設定されたパイプライン用鋼管を製造することができる。 Therefore, the crushing test apparatus 30 of the fourth embodiment can measure the high value of the crushing limit pressure of the test steel pipe 2 by increasing the water pressure in the pressure chamber 16, and the high value of the crushing limit pressure of the pipeline steel pipe can be measured. Can be reproduced with high precision using a test steel pipe.
Further, by performing a crush test using the crush test devices 1, 17, 20, 30 of the first to fourth embodiments, it is possible to manufacture a steel pipe for pipeline in which a crush limit pressure with high accuracy is set. it can.
［実施例１］
　次に、本発明に係るパイプライン用鋼管の圧潰試験装置を使用した圧潰試験方法による圧潰限界圧力の測定と、従来の圧潰試験装置を使用した圧潰試験方法による圧潰限界圧力の測定とを、以下の表１に示すように比較することで、本発明の効果を検証した。 [Example 1]
Next, the measurement of the crush limit pressure by the crush test method using the crush test device for pipeline steel pipe according to the present invention, and the measurement of the crush limit pressure by the crush test method using the conventional crush test device, The effects of the present invention were verified by making a comparison as shown in Table 1 above.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　本発明例１～本発明例５、比較例１，２は、公称管厚が３９mmであり、公称外径が８１２．８mmであり、同一外径形状、同一鋼管特性のパイプライン用鋼管を使用した。
　本発明例１～本発明例３は、試験鋼管２の外周に変形体３が装着されている第１実施形態の圧潰試験装置１を使用した測定結果である。そして、本発明１は、変形体３及び試験鋼管２の軸方向長さの差ΔＬ１＝０．３mmとし、本発明２はΔＬ１＝０．５mmとし、本発明３はΔＬ１＝３．０mmとした。 Inventive Example 1 to Inventive Example 5, and Comparative Examples 1 and 2, the nominal pipe thickness is 39 mm, the nominal outer diameter is 812.8 mm, and the steel pipe for pipeline having the same outer diameter shape and the same steel pipe characteristics is used. did.
Inventive Example 1 to Inventive Example 3 are measurement results using the crushing test apparatus 1 of the first embodiment in which the deformable body 3 is mounted on the outer circumference of the test steel pipe 2. The present invention 1 has a difference ΔL1=0.3 mm in the axial length between the deformable body 3 and the test steel pipe 2, the invention 2 has ΔL1=0.5 mm, and the invention 3 has ΔL1=3.0 mm. ..
　また、本発明例４，５は、試験鋼管２の外周に変形体３を装着し、変形体３の外周にゴムパッキン２１を装着した第２実施形態の圧潰試験装置２０を使用した測定結果である。そして、本発明例４は、変形体３及び試験鋼管２の軸方向長さの差ΔＬ２＝１．０mmとし、本発明例５はΔＬ２＝１．３mmとした。
　また、比較例１は、試験鋼管２の外周に変形体３を装着した第１実施形態の圧潰試験装置１を使用し、変形体３及び試験鋼管２の軸方向長さの差ΔＬ１＝０．１mmとした。さらに、比較例２は、試験鋼管２の外周に変形体３を装着した第１実施形態の圧潰試験装置１を使用し、変形体３及び試験鋼管２の軸方向長さの差ΔＬ１＝６．０mmとした。 In addition, Examples 4 and 5 of the present invention are measurement results using the crushing test apparatus 20 of the second embodiment in which the deformable body 3 is mounted on the outer circumference of the test steel pipe 2 and the rubber packing 21 is mounted on the outer circumference of the deformable body 3. is there. In the invention example 4, the difference in axial length between the deformable body 3 and the test steel pipe 2 was ΔL2=1.0 mm, and in the invention example 5, ΔL2=1.3 mm.
Further, Comparative Example 1 uses the crushing test apparatus 1 of the first embodiment in which the deformable body 3 is attached to the outer circumference of the test steel pipe 2, and the difference ΔL1=0.0.5 in the axial length between the deformable body 3 and the test steel pipe 2. It was set to 1 mm. Furthermore, Comparative Example 2 uses the crushing test apparatus 1 of the first embodiment in which the deformable body 3 is attached to the outer circumference of the test steel pipe 2, and the difference ΔL1=6.6 in the axial length between the deformable body 3 and the test steel pipe 2. It was set to 0 mm.
　そして、本発明例１～本発明例５、比較例１，２の圧潰限界圧力は、パイプライン用鋼管の一部を切断せず実管で測定した結果（実管試験結果）と、パイプライン用鋼管の一部を切断した試験鋼管２を使用して第１及び第３実施形態の圧潰試験装置で測定した結果（圧潰装置結果）を示し、実管試験結果及び圧潰装置結果を比較して測定精度を示した。
　表１から明らかなように、本発明例１～本発明例３は、試験鋼管２の外周に変形体３を装着したことで圧潰試験を行う際に試験鋼管２には摩擦力が発生せず、変形体３の軸方向長さＬｃ１と試験鋼管２の軸方向長さＬｔ１との差ΔＬ１を０．３mm≦ΔＬ１≦５．０mmに設定しているので、測定精度の誤差が０．５％以内に収まっている。 The crushing limit pressures of Inventive Example 1 to Inventive Example 5 and Comparative Examples 1 and 2 are the result of measuring the actual pipe without cutting a part of the pipeline steel pipe (actual pipe test result) and the pipeline. The result (crushing device result) measured by the crushing test device of the first and third embodiments using the test steel pipe 2 obtained by cutting a part of the steel pipe for use is shown, and the actual pipe test result and the crushing device result are compared. The measurement accuracy was shown.
As is clear from Table 1, in the present invention examples 1 to 3 the frictional force is not generated in the test steel pipe 2 when the crushing test is performed by mounting the deformable body 3 on the outer periphery of the test steel pipe 2. Since the difference ΔL1 between the axial length Lc1 of the deformable body 3 and the axial length Lt1 of the test steel pipe 2 is set to 0.3 mm≦ΔL1≦5.0 mm, the measurement accuracy error is 0.5%. It is within.
　また、本発明例４，５は、試験鋼管２の外周に変形体３を装着し、さらに変形体３の外周側にゴムパッキン２１を装着したことで圧潰試験を行う際に試験鋼管２には摩擦力が発生せず、変形体３の軸方向長さＬｃ２と試験鋼管２の軸方向長さＬｔ２との差ΔＬ２を１．０mm≦ΔＬ２≦１．３mmに設定しているので、測定精度の誤差が１．０％未満に収まっている。
　一方、比較例１は、試験鋼管２の外周に変形体３を装着した第１実施形態の圧潰試験装置１を使用しているが、変形体３及び試験鋼管２の軸方向長さの差ΔＬ１＝０．３mm未満としたことで、試験鋼管２が軸方向に塑性変形して天盤１１の下面１１ｈ及び底盤１０の上面１０ｈに接触して摩擦力が発生し、試験鋼管２の圧潰限界圧力が高い値を示してしまい、測定誤差が５．８％と大きくなった。 In addition, in Examples 4 and 5 of the present invention, the deformable body 3 was attached to the outer circumference of the test steel pipe 2, and the rubber packing 21 was attached to the outer peripheral side of the deformable body 3, so that the test steel pipe 2 was not subjected to the crush test. Since no frictional force is generated and the difference ΔL2 between the axial length Lc2 of the deformable body 3 and the axial length Lt2 of the test steel pipe 2 is set to 1.0 mm≦ΔL2≦1.3 mm, The error is less than 1.0%.
On the other hand, Comparative Example 1 uses the crushing test apparatus 1 of the first embodiment in which the deformable body 3 is mounted on the outer circumference of the test steel pipe 2, but the difference ΔL1 in the axial length between the deformable body 3 and the test steel pipe 2 is used. = Less than 0.3 mm, the test steel pipe 2 is plastically deformed in the axial direction and comes into contact with the lower surface 11h of the top 11 and the upper surface 10h of the bottom 10 to generate frictional force, and the crushing limit pressure of the test steel pipe 2 Showed a high value, and the measurement error was as large as 5.8%.
　また、比較例２は、測定誤差が１０％以上である。これは、比較例２は試験鋼管２の外周に変形体３を装着した第１実施形態の圧潰試験装置１を使用しているが、変形体３及び試験鋼管２の軸方向長さの差ΔＬ１＝５．０mmを上回っている。これにより、圧力室１６の水圧が上昇しているときに、変形体３が、試験鋼管２の端面と天盤１１の下面１１ｈとの間に入り込んだ状態で変形して圧力室１６の液密が不可能になり、試験鋼管２が圧潰する前に圧力室１６の最大圧力が大きく低下してしまった。
　したがって、本願発明に係る第１実施形態の圧潰試験装置１を使用した方法、第３実施形態の圧潰試験装置２０を使用した方法が、パイプライン用鋼管の圧潰限界圧力を試験鋼管で高精度に再現することができることが確認された。なお、第４実施形態の圧潰試験装置３０を使用した方法も、パイプライン用鋼管の圧潰限界圧力を試験鋼管で高精度に再現することができる。 In Comparative Example 2, the measurement error is 10% or more. This comparative example 2 uses the crushing test apparatus 1 of the first embodiment in which the deformable body 3 is mounted on the outer circumference of the test steel pipe 2, but the difference ΔL1 in the axial length between the deformable body 3 and the test steel pipe 2 is used. It exceeds 5.0 mm. As a result, when the water pressure in the pressure chamber 16 is rising, the deformable body 3 is deformed in a state of entering between the end surface of the test steel pipe 2 and the lower surface 11h of the roof 11 and the liquid tightness of the pressure chamber 16 is increased. Became impossible, and the maximum pressure of the pressure chamber 16 was greatly reduced before the test steel pipe 2 was crushed.
Therefore, the method using the crushing test apparatus 1 according to the first embodiment of the present invention and the method using the crushing test apparatus 20 according to the third embodiment are highly accurate in determining the crushing limit pressure of the steel pipe for pipeline with the test steel pipe. It was confirmed that it can be reproduced. The method using the crushing test apparatus 30 of the fourth embodiment can also accurately reproduce the crushing limit pressure of the pipeline steel pipe with the test steel pipe.
［実施例２］
　次に、本発明に係るパイプライン用鋼管の圧潰試験装置を使用した圧潰試験方法による圧潰限界圧力の測定と、従来の圧潰試験装置を使用した圧潰試験方法による圧潰限界圧力の測定を行い、塑性圧潰の再現の有無を判定することで、本発明の効果を検証した。
　塑性圧潰の再現の有無は、以下の（１）式で算出される圧潰試験を行った試験鋼管２の内径変位ΔＲ（測定した内径変化の平均値）と、試験鋼管２の弾性変形線からのかい離量との比較により判断し、試験鋼管２の内径変位ΔＲが、弾性変形線からかい離量が０．２％以上となったときに塑性圧痕が再現されていると判定する。
　ΔＲ　＝　－（ＰＲ２）／（ｔＥ）　………　（１）
　なお、Ｐは圧力（Ｍｐａ）、Ｒは試験鋼管２の初期内径（mm）、ｔは試験鋼管２の厚さ（mm）、Ｅはヤング率（Ｍｐａ）である。 [Example 2]
Next, the crushing limit pressure is measured by the crushing test method using the crushing test device for pipeline steel pipes according to the present invention, and the crushing limit pressure is measured by the crushing test method using the conventional crushing test device. The effect of the present invention was verified by determining whether crushing was reproduced.
Whether or not the plastic crush is reproduced is determined from the elastic deformation line of the test steel pipe 2 and the inner diameter displacement ΔR (average value of the measured inner diameter change) of the test steel pipe 2 subjected to the crush test calculated by the following formula (1). Judgment is made by comparison with the amount of separation, and when the inner diameter displacement ΔR of the test steel pipe 2 is more than 0.2% from the elastic deformation line, it is judged that the plastic indentation is reproduced.
ΔR =-(PR 2 )/(tE) ……… (1)
Note that P is the pressure (Mpa), R is the initial inner diameter (mm) of the test steel pipe 2, t is the thickness (mm) of the test steel pipe 2, and E is the Young's modulus (Mpa).
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　本発明例６と比較例３は、公称管厚が４０mmであり、公称外径が６９１mmであり、同一外径形状、同一鋼管特性のパイプライン用鋼管を使用した。
　本発明例６は、試験鋼管２の外周に変形体３が装着されているとともに、天盤１１を貫通して底盤１０にねじ込まれることで第１及び第２連結ボルト１４，１５に発生する軸力が、段差部１０ｂ，１１ｂの軸方向に直交する段差面及びこれに対面する中間盤１２の軸方向に直交する面の間に装着されている環状パッキン２３に大きな密着力を作用し、圧力室１６の水圧を大幅に高めることが可能となる第２実施形態の圧潰試験装置１７（図４参照）を使用した測定結果である。そして、本発明例６は、変形体３及び試験鋼管２の軸方向長さの差ΔＬ１＝１．０mmとした。一方、比較例３は、試験鋼管２の外周に変形体３を装着した第２実施形態の圧潰試験装置１７を使用し、変形体３及び試験鋼管２の軸方向長さの差ΔＬ１＝６．０mmとした。 Inventive Example 6 and Comparative Example 3 used steel pipes for pipelines having a nominal pipe thickness of 40 mm, a nominal outer diameter of 691 mm, the same outer diameter shape, and the same steel pipe characteristics.
In the invention example 6, the deformable body 3 is mounted on the outer circumference of the test steel pipe 2, and the shaft generated in the first and second connecting bolts 14 and 15 by penetrating the roof 11 and being screwed into the bottom 10 The force exerts a large adhesion force on the annular packing 23 mounted between the step surfaces of the step portions 10b and 11b which are orthogonal to the axial direction and the surface of the intermediate plate 12 which faces the step surfaces and which is orthogonal to the axial direction, and the pressure is applied. It is a measurement result which used the crushing test apparatus 17 (refer FIG. 4) of 2nd Embodiment which can raise the water pressure of the chamber 16 significantly. Then, in Inventive Example 6, the difference in axial length between the deformable body 3 and the test steel pipe 2 was ΔL1=1.0 mm. On the other hand, Comparative Example 3 uses the crushing test apparatus 17 of the second embodiment in which the deformable body 3 is attached to the outer circumference of the test steel pipe 2, and the difference ΔL1=6.x in the axial length between the deformable body 3 and the test steel pipe 2. It was set to 0 mm.
　図７は、本発明例６の試験鋼管２について圧力室１６の水圧変化と内径変位の関係を示すものであり、本発明例６の試験鋼管２は、圧力室１６の水圧上昇とともに塑性変形していき、弾性変形線からのかい離量が０．８％のときに塑性圧痕が再現されることが検証された。そして、この本発明例６の塑性圧痕の再現の際には、５０ＭＰａを超える超高圧での圧潰試験が再現できることも検証できた。
　一方、変形体３及び試験鋼管２の軸方向長さの差ΔＬ１＝６．０mmとした比較例３は、圧力室１６の水圧が上昇すると、変形体３が試験鋼管２の端面と天盤１１の下面１１ｈとの間に入り込んだ状態で変形して圧力室１６の液密が不可能になり、試験鋼管２が圧潰する前に圧力室１６の最大圧力が大きく低下してしまった。この際の、試験鋼管２の内径変位ΔＲが弾性変形線からかい離量が０．０５％となり、弾性変形状態となって圧力室１６の水が外部にリークするので、圧潰試験は再現することができない。 FIG. 7 shows the relationship between the water pressure change and the inner diameter displacement of the pressure chamber 16 for the test steel pipe 2 of the present invention example 6. The test steel pipe 2 of the present invention example 6 plastically deforms as the water pressure of the pressure chamber 16 increases. It was verified that the plastic indentation was reproduced when the distance from the elastic deformation line was 0.8%. It was also verified that when the plastic indentation of Inventive Example 6 was reproduced, a crushing test at an ultrahigh pressure exceeding 50 MPa could be reproduced.
On the other hand, in Comparative Example 3 in which the difference ΔL1=6.0 mm in the axial length between the deformable body 3 and the test steel pipe 2, when the water pressure in the pressure chamber 16 increases, the deformable body 3 causes the end face of the test steel pipe 2 and the roof 11 to rise. It deformed in a state of entering between the lower surface 11h and the lower surface 11h, making liquid tightness of the pressure chamber 16 impossible, and the maximum pressure of the pressure chamber 16 greatly decreased before the test steel pipe 2 was crushed. At this time, the inner diameter displacement ΔR of the test steel pipe 2 is 0.05% from the elastic deformation line, and the water in the pressure chamber 16 leaks to the outside in the elastically deformed state, so that the crush test can be reproduced. Can not.
１，１７，２０，３０　圧潰試験装置
２　試験鋼管
２ａ　試験鋼管の軸方向の他方の端面
２ｂ　試験鋼管の軸方向の一方の端面
３　変形体
３ａ，３ｂ　変形体の軸方向の端面
４　装置本体
５　加圧水供給部
６　歪み計
７　圧力計
８　演算部
８ａ　入力部
８ｂ　圧潰圧力演算部
８ｃ　表示部
１０　底盤
１０ａ　貫通部
１０ｂ　段差部
１０ｃ，１０ｄ　ねじ孔
１０ｈ　上面
１１　天盤
１１ａ　貫通部
１１ｂ　段差部
１１ｃ　貫通孔
１１ｄ　貫通孔
１１ｅ　水供給路
１１ｆ　圧力計測路
１１ｈ　下面
１２　中間盤
１２ａ　内周面
１２ｃ　貫通孔
１４　第１連結ボルト
１５　第２連結ボルト
１６　圧力室
２１　ゴムパッキン
２１ａ，２１ｂ　肉厚部
２２　Ｏリング
２３　環状パッキン
ＳＴ　試験空間
Ｌｃ１　第１実施形態の変形体の軸方向長さ
Ｌｔ１　第１実施形態の試験鋼管の軸方向長さ
ΔＬ１　第１実施形態の変形体及び試験鋼管の軸方向長さの差
Ｌｃ２　第２実施形態の変形体の軸方向長さ
Ｌｔ２　第２実施形態の試験鋼管の軸方向長さ
ΔＬ２　第２実施形態の変形体及び試験鋼管の軸方向長さの差 1, 17, 20, 30 Crush test device 2 Test steel pipe 2a Another end face 2b of test steel pipe in the axial direction One end face 3 of test steel pipe in the axial direction 3 Deformation bodies 3a, 3b End face 4 of the deformation body 4 Device body 5 Pressurized water supply unit 6 Strain gauge 7 Pressure gauge 8 Calculation unit 8a Input unit 8b Crush pressure calculation unit 8c Display unit 10 Bottom plate 10a Penetration part 10b Steps 10c, 10d Screw hole 10h Top surface 11 Top 11a Penetration part 11b Step part 11c Penetration hole 11d Through hole 11e Water supply path 11f Pressure measurement path 11h Lower surface 12 Intermediate board 12a Inner peripheral surface 12c Through hole 14 First connecting bolt 15 Second connecting bolt 16 Pressure chamber 21 Rubber packing 21a, 21b Thick portion 22 O-ring 23 Ring Packing ST Test space Lc1 Axial length Lt1 of deformable body of first embodiment Axial length ΔL1 of test steel pipe of first embodiment Difference Lc2 between axial length of deformable body and test steel pipe of first embodiment Axial Length Lt2 of Deformed Body of Second Embodiment Axial Length ΔL2 of Test Steel Pipe of Second Embodiment Difference in Axial Length of Deformed Body and Test Steel Pipe of Second Embodiment

Claims (11)

  1. 　パイプライン用鋼管の一部より切断され形成されたリング形状の試験鋼管の外周に、前記試験鋼管に対して軸方向長さを長く設定して合成樹脂で形成した円筒形状の変形体を装着する工程と、
    　互いに対向配置した一対の対向壁の間を軸が延在するように前記試験鋼管及び前記変形体を配置し、前記一対の対向壁に前記変形体の軸方向の両端面が密着した状態で前記一対の対向壁で前記変形体を挟持する工程と、
    　前記一対の対向壁及び前記変形体の外周面に対向する周壁で前記変形体の外周面を囲んで形成した圧力室に流体を供給し、前記変形体の外周面に加圧した前記流体を作用させる工程と、
    　前記試験鋼管の内径を測定する工程と、
    　前記圧力室の前記流体の圧力を測定する工程と、
    　前記試験鋼管の内径測定値及び前記圧力室の前記流体の圧力測定値に基づいて圧潰した前記試験鋼管の圧潰限界圧力を演算する工程と、を備えたことを特徴とするパイプライン用鋼管の圧潰試験方法。     On the outer circumference of a ring-shaped test steel pipe formed by being cut from a part of a pipeline steel pipe, a cylindrical deformable body formed of synthetic resin with an axial length set longer than that of the test steel pipe is mounted. Process,
    The test steel pipe and the deformable body are arranged so that an axis extends between a pair of opposing walls arranged to face each other, and the axial ends of the deformable body are in close contact with the pair of opposing walls. Sandwiching the deformable body between a pair of opposing walls,
    A fluid is supplied to a pressure chamber formed by surrounding the outer peripheral surface of the deformable body with a pair of opposing walls and a peripheral wall facing the outer peripheral surface of the deformable body, and the pressurized fluid acts on the outer peripheral surface of the deformable body. And the process of
    Measuring the inner diameter of the test steel pipe,
    Measuring the pressure of the fluid in the pressure chamber,
    Crushing a pipeline steel pipe, comprising: calculating a crushing limit pressure of the crushed test steel pipe based on an inner diameter measurement value of the test steel pipe and a pressure measurement value of the fluid in the pressure chamber. Test method.
  2. 　前記変形体の軸方向長さをＬｃ１、前記試験鋼管の軸方向長さをＬｔ１とすると、前記変形体及び前記試験鋼管の軸方向長さの差ΔＬ１（Ｌｃ１－Ｌｔ１）が、０．３mm≦ΔＬ１≦５．０mmであることを特徴とする請求項１記載のパイプライン用鋼管の圧潰試験方法。 When the axial length of the deformable body is Lc1 and the axial length of the test steel pipe is Lt1, the difference ΔL1 (Lc1-Lt1) in the axial length of the deformable body and the test steel pipe is 0.3 mm≦. The method for crushing a steel pipe for pipeline according to claim 1, wherein ΔL1≦5.0 mm.
  3. 　パイプライン用鋼管の一部を切断してリング形状の試験鋼管を形成する工程と、
    　前記試験鋼管の外周に、当該試験鋼管に対して軸方向長さを長く設定して合成樹脂で形成した円筒形状の変形体を装着する工程と、
    　前記変形体の外周に弾性体からなるシール部材を装着する工程と、
    　互いに対向配置した一対の対向壁の間を軸が延在するように前記試験鋼管、前記変形体及び前記シール部材を配置し、前記一対の対向壁に前記変形体の軸方向の両端面が密着し、且つ前記シール部材を弾性変形しながら密着した状態で前記一対の対向壁で前記変形体を挟持する工程と、
    　前記一対の対向壁及び前記変形体の外周面に対向する周壁で前記変形体の外周面を囲んで形成した圧力室に流体を供給し、前記変形体の外周面に加圧した流体を作用させる工程と、
    　前記試験鋼管の内径を測定する工程と、
    　前記圧力室の前記流体の圧力を測定する工程と、
    　前記試験鋼管の内径測定値及び前記圧力室の前記流体の圧力測定値に基づいて圧潰した前記試験鋼管の圧潰限界圧力を演算する工程と、を備えたことを特徴とするパイプライン用鋼管の圧潰試験方法。     A step of cutting a part of the steel pipe for a pipeline to form a ring-shaped test steel pipe,
    On the outer periphery of the test steel pipe, a step of mounting a cylindrical deformable body formed of synthetic resin by setting the axial length of the test steel pipe to be long,
    Mounting a seal member made of an elastic body on the outer periphery of the deformable body,
    The test steel pipe, the deformable body, and the seal member are arranged so that an axis extends between a pair of opposed walls arranged to face each other, and both axial end faces of the deformable body are closely attached to the pair of opposed walls. And sandwiching the deformable body with the pair of opposing walls in a state in which the seal member is elastically deformed and closely attached,
    A fluid is supplied to a pressure chamber formed by surrounding the outer peripheral surface of the deformable body with a pair of opposing walls and a peripheral wall facing the outer peripheral surface of the deformable body, and the pressurized fluid acts on the outer peripheral surface of the deformable body. Process,
    Measuring the inner diameter of the test steel pipe,
    Measuring the pressure of the fluid in the pressure chamber,
    Crushing a pipeline steel pipe, comprising: calculating a crushing limit pressure of the crushed test steel pipe based on an inner diameter measurement value of the test steel pipe and a pressure measurement value of the fluid in the pressure chamber. Test method.
  4. 　前記変形体の軸方向長さをＬｃ２、前記試験鋼管の軸方向長さをＬｔ２とすると、前記変形体及び前記試験鋼管の軸方向長さの差ΔＬ２（Ｌｃ２－Ｌｔ２）が、１．０mm≦ΔＬ２≦１．３mmであることを特徴とする請求項３記載のパイプライン用鋼管の圧潰試験方法。 When the axial length of the deformable body is Lc2 and the axial length of the test steel pipe is Lt2, the difference ΔL2 (Lc2-Lt2) in the axial length between the deformable body and the test steel pipe is 1.0 mm≦. The method for crushing a steel pipe for pipeline according to claim 3, wherein ΔL2≦1.3 mm.
  5. 　請求項１から４の何れか一項のパイプライン用鋼管の圧潰試験方法を行う工程を経て前記パイプライン用鋼管を製造することを特徴とするパイプライン用鋼管の製造方法。 A method for manufacturing a steel pipe for a pipeline, which comprises manufacturing the steel pipe for a pipeline through a step of performing the method for crushing a steel pipe for a pipeline according to any one of claims 1 to 4.
  6. 　パイプライン用鋼管の一部を切断してリング形状に形成した試験鋼管と、
    　前記試験鋼管に対して軸方向長さを長く設定して合成樹脂で形成した円筒形状の部材であり、前記試験鋼管の外周に装着される変形体と、
    　前記変形体の軸方向の両端面が密着するように前記変形体を軸方向から挟持して互いに対向配置されている一対の対向壁と、当該一対の対向壁から延在して前記変形体の外周面を囲む周壁とを備えて前記変形体の外周を囲む圧力室を形成している装置本体と、
    　前記圧力室に流体を供給する流体供給手段と、
    　前記試験鋼管の内径を測定する内径測定手段と、
    　前記圧力室の前記流体の圧力を測定する流体圧力測定手段と、
    　前記内径測定手段で測定した内径測定値及び前記流体圧力測定手段で測定した前記流体の圧力測定値に基づいて圧潰した前記試験鋼管の圧潰限界圧力を演算する演算手段と、を備えたことを特徴とするパイプライン用鋼管の圧潰試験装置。     A test steel pipe formed by cutting a part of the steel pipe for a pipeline into a ring shape,
    A cylindrical member formed of synthetic resin by setting the axial length of the test steel pipe to be long, and a deformable body mounted on the outer periphery of the test steel pipe,
    A pair of opposing walls that are arranged to face each other by sandwiching the deformable body from the axial direction so that both axial end surfaces of the deformable body are in close contact with each other, and the deformable body extends from the pair of opposing walls. An apparatus main body having a peripheral wall surrounding an outer peripheral surface and forming a pressure chamber surrounding the outer periphery of the deformable body;
    Fluid supply means for supplying fluid to the pressure chamber,
    An inner diameter measuring means for measuring the inner diameter of the test steel pipe,
    Fluid pressure measuring means for measuring the pressure of the fluid in the pressure chamber,
    Arithmetic means for calculating a crushing limit pressure of the test steel pipe crushed based on the inner diameter measurement value measured by the inner diameter measurement means and the pressure measurement value of the fluid measured by the fluid pressure measurement means. Crush tester for steel pipes for pipelines.
  7. 　前記変形体の軸方向長さをＬｃ１、前記試験鋼管の軸方向長さをＬｔ１とすると、前記変形体及び前記試験鋼管の軸方向長さの差ΔＬ１（Ｌｃ１－Ｌｔ１）が、０．３mm≦ΔＬ１≦５．０mmであることを特徴とする請求項６記載のパイプライン用鋼管の圧潰試験装置。 When the axial length of the deformable body is Lc1 and the axial length of the test steel pipe is Lt1, the difference ΔL1 (Lc1-Lt1) in the axial length of the deformable body and the test steel pipe is 0.3 mm≦. 7. The crushing test apparatus for steel pipes for pipelines according to claim 6, wherein ΔL1≦5.0 mm.
  8. 　パイプライン用鋼管の一部を切断してリング形状に形成した試験鋼管と、
    　前記試験鋼管に対して軸方向長さを長く設定して合成樹脂で形成した円筒形状の部材であり、前記試験鋼管の外周に装着される変形体と、
    　前記変形体の外周に装着される弾性体からなるシール部材と、
    　前記変形体の軸方向の両端面が密着し、且つ前記シール部材が弾性変形しながら密着するように前記変形体及び前記シール部材を軸方向から挟持して互いに対向配置されている一対の対向壁と、当該一対の対向壁から延在して前記変形体の外周面を囲む周壁とを備えて前記変形体の外周を囲む圧力室を形成している装置本体と、
    　前記圧力室に流体を供給する流体供給手段と、
    　前記試験鋼管の内径を測定する内径測定手段と、
    　前記圧力室の前記流体の圧力を測定する流体圧力測定手段と、
    　前記内径測定手段で測定した内径測定値及び前記流体圧力測定手段で測定した前記流体の圧力測定値に基づいて圧潰した前記試験鋼管の圧潰限界圧力を演算する演算手段と、を備えたことを特徴とするパイプライン用鋼管の圧潰試験装置。     A test steel pipe formed by cutting a part of the steel pipe for a pipeline into a ring shape,
    A cylindrical member formed of synthetic resin by setting the axial length of the test steel pipe to be long, and a deformable body mounted on the outer periphery of the test steel pipe,
    A seal member made of an elastic body attached to the outer periphery of the deformable body,
    A pair of opposed walls that are arranged to face each other by sandwiching the deformable body and the seal member from the axial direction so that both axial end surfaces of the deformable body are in close contact with each other and the seal member is in close contact while being elastically deformed. And a device main body that forms a pressure chamber that surrounds the outer periphery of the deformable body by including a peripheral wall that extends from the pair of opposing walls and that surrounds the outer peripheral surface of the deformable body,
    Fluid supply means for supplying fluid to the pressure chamber,
    An inner diameter measuring means for measuring the inner diameter of the test steel pipe,
    Fluid pressure measuring means for measuring the pressure of the fluid in the pressure chamber,
    Arithmetic means for calculating a crushing limit pressure of the test steel pipe crushed based on the inner diameter measurement value measured by the inner diameter measurement means and the pressure measurement value of the fluid measured by the fluid pressure measurement means. Crush tester for steel pipes for pipelines.
  9. 　前記変形体の軸方向長さをＬｃ２、前記試験鋼管の軸方向長さをＬｔ２とすると、前記変形体及び前記試験鋼管の軸方向長さの差ΔＬ２（Ｌｃ２－Ｌｔ２）が、１．０mm≦ΔＬ２≦１．３mmであることを特徴とする請求項８記載のパイプライン用鋼管の圧潰試験装置。 When the axial length of the deformable body is Lc2 and the axial length of the test steel pipe is Lt2, the difference ΔL2 (Lc2-Lt2) in the axial length between the deformable body and the test steel pipe is 1.0 mm≦. 9. The crushing test device for steel pipes for pipelines according to claim 8, wherein ΔL2≦1.3 mm.
  10. 　前記シール部材は、前記変形体に対して軸方向長さを長くした円筒形状の弾性体であることを特徴とする請求項８又は９記載のパイプライン用鋼管の圧潰試験装置。 The crush test apparatus for a pipeline steel pipe according to claim 8 or 9, wherein the seal member is a cylindrical elastic body having an axial length longer than that of the deformable body.
  11. 　前記シール部材は、前記変形体の軸方向の両端面の一部に形成した環状の凹部に嵌まり込んでいるＯリングであることを特徴とする請求項８又は９記載のパイプライン用鋼管の圧潰試験装置。 10. The steel pipe for a pipeline according to claim 8 or 9, wherein the seal member is an O-ring fitted in an annular recess formed in a part of both end surfaces in the axial direction of the deformable body. Crush test device.
PCT/JP2019/050773 2018-12-25 2019-12-25 Crushing test method for steel pipe for pipeline, manufacturing method for steel pipe for pipeline, and crushing test device WO2020138145A1 (en)

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