Metal-pipe bonded body, pipe expansion method of metal-pipe bonded body, and method for inspecting metal-pipe bonded body

• US 20020014514A1
• Filed: 05/17/2001
• Published: 02/07/2002
• Est. Priority Date: 05/18/2000
• Status: Active Grant

• Current Assignee: Daido Tokushuko Kabushiki Kaisha
• Original Assignee: Daido Tokushuko Kabushiki Kaisha
• Inventors: Kito, Kazushige, Yamada, Ryuzo, Horio, Hirotsugu, Inagaki, Shigeyuki, Shimizu, Takao
• Granted Patent: US 6,592,154 B2
• Time in Patent Office: Days
• US Class Current: 228/104
• CPC Class Codes: B23K 2101/06 Tubes
• CPC Class Codes: B23K 31/12 relating to investigating the properties, e.g. the weldability, of materials
• CPC Class Codes: F16L 13/00 Non-disconnectible pipe-joints, e.g. soldered, adhesive or caulked joints joints for rigid pipes of plastics F16L47/00; non-disconnectible pipe-joints to walls or other pipes, the joined pipe axis being perpendicular to the plane of the wall or to the axis of the other pipe F16L41/082
• CPC Class Codes: G01N 2291/0234 Metals, e.g. steel
• CPC Class Codes: G01N 2291/0251 Solidification, icing, curing composites, polymerisation
• CPC Class Codes: G01N 2291/02854 Length, thickness
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/2634 cylindrical from outside
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/225 Supports, positioning or alignment in moving situation

Abstract

In diffusion bonding a metal pipe 112e and a metal pipe 114e via a bonded interface 116e formed at the end parts, a portion that is inclined with respect to the radial direction of metal pipes 112e and 114e is provided at least at part of bonded interface 116. In this case, the inclination angle φ of bonded interface 116e and the tip angle 2θ of a pipe expansion tool 130 are preferably in the relationship, 0<φ≦θ+60°. In performing pipe expansion of such a metal pipe bonded body 110e, the pipe expansion tool 130 is moved from the metal pipe 112e, at which the inclined portion of junction face 116e is formed to have a protruding shape, towards the metal pipe 114e, at which the inclined portion of junction face 116e is formed to have a recessed shape. Furthermore, the inner diameter at the vicinity of the junction face of the metal pipe junction may be made larger than the inner diameter at positions away from the junction face.

Claims

1. A metal-pipe bonded body, comprising:

first and second metal pipes which are diffusion bonded via a bonded interface defined by end parts thereof,

wherein at least part of said bonded interface is inclined with respect to a radial direction of said metal-pipe bonded body.

2. The metal-pipe bonded body as set forth in claim 1, wherein an inside diameter of said end part of each of said first and second metal pipes is larger than an inside diameter of an intermediate part of each of said first and second metal pipes, said intermediate part being disposed apart from said end part in its longitudinal direction.

3. The metal-pipe bonded body as set forth in claim 1, wherein said metal-pipe bonded body is an expandable metal-pipe bonded body which is formed by expanding said first and second metal pipes which have been diffusion bonded via said bonded interface.

4. The metal-pipe bonded body as set forth in claim 3, wherein an inside diameter of said end part of each of said first and second metal pipes is larger than an inside diameter of an intermediate part of each of said first and second metal pipes, said intermediate part being disposed apart from said end part in its longitudinal direction.

5. The metal-pipe bonded body as set forth in claim 3, wherein said expandable metal-pipe bonded body is formed by expanding said first and second metal pipes which have been diffusion bonded via said bonded interface, with a pipe expansion tool having a tip angle satisfying a following relationship:

0<

φ

≦

θ

+60°

where (φ

) indicates an inclination angle (φ

) of said part of said bonded interface and (θ

) denotes a half of the tip angle (2θ

) of said tool.

6. The metal-pipe bonded body as set forth in claim 2, wherein an inside diameter of said end part of each of said first and second metal pipes is larger than an inside diameter of an intermediate part of each of said first and second metal pipes, before said first and second metal pipes are subjected to the expansion with said tool, and wherein said intermediate part being disposed apart from said end part in its longitudinal direction.

7. The metal-pipe bonded body as set forth in claim 1, wherein said inclined part of said bonded interface is subject to an inspection with ultrasonic flaw detection, after said first and second have been diffusion bonded via said bonded interface.

8. The metal-pipe bonded body as set forth in claim 7, wherein said inspection comprising:

a first flaw detection process, in which an ultrasonic wave is made incident perpendicularly on said inclined part and the reflection echo that is reflected from said inclined part is detected.

9. The metal-pipe bonded body as set forth in claim 8, wherein said ultrasonic wave is a focused ultrasonic wave.

10. The metal-pipe bonded body as set forth in claim 8, wherein said bonded interface has a perpendicular part which is in parallel with the radial direction of said metal-pipe bonded body, and wherein said inspection further comprises:

a second flaw detection process, in which the ultrasonic wave is made obliquely incident on said perpendicular part and the reflection echo that is reflected from said perpendicular part is detected.

11. A pipe expansion method of metal-pipe bonded body, said bonded body including first and second metal pipes which are diffusion bonded via a bonded interface defined by faced end parts thereof, wherein at least part of said bonded interface is inclined with respect to a radial direction of said metal-pipe bonded body, and said metal-pipe bonded body is enlarged by the insertion of a pipe expanding tool into the interior of the metal pipe bonded body, said pipe expansion method comprising:

moving said pipe expanding tool from said first pipe towards said second pipe, wherein said first pipe has one of said end parts protruding towards said second pipe, and said second pipe has the other of said end parts which is recessed so as to receive said protruded end parts of said first pipe.

13. The inspection method as set forth in claim 12, wherein said ultrasonic wave is a focused ultrasonic wave.

14. The inspection method as set forth in claim 12, wherein in said first flaw detection process, an ultrasonic probe, which transmits said ultrasonic wave, is scanned in at least one of the circumferential direction and longitudinal direction of said inclined part.

15. The inspection method as set forth in claim 13, wherein in said first flaw detection process, an ultrasonic probe, which transmits said ultrasonic wave, is scanned in at least one of the circumferential direction and the longituidnal direction of said inclined part.

16. The inspection method as set forth in claim 12, wherein said bonded interface has a perpendicular part which is extended in parallel with a radial direction of said bonded body, and said method further comprises:

as a second flaw detection process including;

making an ultrasonic wave obliquely incident on said perpendicular part, and

detecting the reflection echo that is reflected from said perpendicular part.

17. The inspection method as set forth in claim 12, further comprising:

a first pipe thickness measurement process, in which an ultrasonic wave is made perpendicularly incident on said first metal pipe and a pipe thickness of said first metal pipe is measured from the difference in the arrival times of a surface echo and a bottom face echo;

a second pipe thickness measurement process, in which an ultrasonic wave is made perpendicularly incident on said second metal pipe and a pipe thickness of said second metal pipe is measured from the difference in the arrival times of a surface echo and a bottom face echo;

a surface offset measurement process, in which the surface offset between said first and second metal pipes is measured; and

an inner face offset calculation process, in which an inner face offset between said first and second metal pipes is determined from the pipe thickness of said first metal pipe, the pipe thickness of said second metal pipe, and said surface offset.

18. The inspection method as set forth in claim 12, further comprising:

a backward scattering intensity measurement process, in which an ultrasonic wave is transmitted in the direction of the interior of said first metal pipe at the vicinity of said bonded interface and the backward scattering intensity is measured, and

a crystal grain diameter calculation process, in which a previously determined correlation between the crystal grain diameter of said metal pipe and the backward scattering intensity is used to determine the size of the crystal grain from the magnitude of said backward scattering intensity that was measured in said backward scattering intensity measurement process.

19. The inspection method as set forth in claim 12, further comprising:

a solidified phase detection process, in which an ultrasonic wave is made obliquely incident towards the inner face of said end part of said metal pipe bonded body and the position of the reflection echo that is reflected from the inner face of said metal pipe bonded body is measured.

12. An inspection method for metal pipe bonded body, said bonded body including first and second metal pipes which are diffusion bonded via a bonded interface defined by faced end parts thereof, wherein at least part of said bonded interface is inclined with respect to a radial direction of said metal-pipe bonded body, said inspection method comprising

a first flaw detection process, including the steps of,

making an ultrasonic wave incident perpendicularly on said inclined part;

and

detecting the reflection echo that is reflected from said inclined part.