Seamless pipe and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-12140265-B2
Application number	US-202117800963-A
Country	US
Kind code	B2
Filing date	Jan 18, 2021
Priority date	Feb 26, 2020
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

The seamless pipe in which a thin-walled portion in a pipe circumferential direction is formed in a pipe axial direction, in which a line segment formed by connecting one end and the other end of the thin-walled portion along a pipe surface with a shortest distance in a formation direction of the thin-walled portion is inclined at an angle α of 5.0° or more with respect to the pipe axial direction. It is preferable that one end and the other end of the thin-walled portion are set from a region in a pipe selected with a shorter length between a length of 1.0 m in the pipe axial direction and 90% of a length in the pipe axial direction where the thin-walled portion turns once in the pipe circumferential direction.

First claim

The invention claimed is:

1. A seamless pipe in which a thin-walled portion in a pipe circumferential direction is formed in a pipe axial direction, wherein
a line segment formed by connecting one end and the other end of the thin-walled portion along a pipe surface with a shortest distance in a formation direction of the thin-walled portion is inclined at an angle α of 5.0° or more with respect to the pipe axial direction.

2. The seamless pipe according to claim 1 , wherein
one end and the other end of the thin-walled portion are set from a region in a pipe selected with a shorter length between a length of 1.0 m in the pipe axial direction and 90% of a length in the pipe axial direction where the thin-walled portion turns once in the pipe circumferential direction.

3. The seamless pipe according to claim 1 , wherein
an average outer diameter D ave [mm] and the angle α [°] satisfy the following formula (1);
D ave /α=0.5 to 15.0 [mm/°] . . . .   Formula (1).

4. The seamless pipe according to claim 2 , wherein
an average outer diameter D ave [mm] and the angle α[°] satisfy the following formula (1);
D ave /α=0.5 to 15.0 [mm/°] . . . .   Formula (1).

5. The seamless pipe according to claim 1 , wherein
compressive yield strength [MPa] in the pipe axial direction/tensile yield strength [MPa] in the pipe axial direction is 0.85 or more.

6. The seamless pipe according to claim 2 , wherein
compressive yield strength [MPa] in the pipe axial direction/tensile yield strength [MPa] in the pipe axial direction is 0.85 or more.

7. The seamless pipe according to claim 3 , wherein
compressive yield strength [MPa] in the pipe axial direction/tensile yield strength [MPa] in the pipe axial direction is 0.85 or more.

8. The seamless pipe according to claim 4 , wherein
compressive yield strength [MPa] in the pipe axial direction/tensile yield strength [MPa] in the pipe axial direction is 0.85 or more.

9. The seamless pipe according to claim 1 , wherein
at least one of pipe end portions on both sides is provided with a fastening portion of a male thread or a female thread and a radius of curvature of a corner portion formed by a flank surface and a bottom surface of a thread valley of the fastening portion is 0.2 mm or more.

10. The seamless pipe according to claim 3 , wherein
at least one of pipe end portions on both sides is provided with a fastening portion of a male thread or a female thread and a radius of curvature of a corner portion formed by a flank surface and a bottom surface of a thread valley of the fastening portion is 0.2 mm or more.

11. The seamless pipe according to claim 5 , wherein
at least one of pipe end portions on both sides is provided with a fastening portion of a male thread or a female thread and a radius of curvature of a corner portion formed by a flank surface and a bottom surface of a thread valley of the fastening portion is 0.2 mm or more.

12. The seamless pipe according to claim 9 , wherein
at least one of the pipe end portions on both sides is provided with the fastening portion of the male thread or the female thread, and the fastening portion is provided with a metal-to-metal seal portion and a torque shoulder portion.

13. The seamless pipe according to claim 10 , wherein
at least one of the pipe end portions on both sides is provided with the fastening portion of the male thread or the female thread, and the fastening portion is provided with a metal-to-metal seal portion and a torque shoulder portion.

14. The seamless pipe according to claim 11 , wherein
at least one of the pipe end portions on both sides is provided with the fastening portion of the male thread or the female thread, and the fastening portion is provided with a metal-to-metal seal portion and a torque shoulder portion.

15. A method for manufacturing the seamless pipe according to claim 1 , the method comprising:
performing piercing of a pipe material by hot rolling, while rotating the pipe material and advancing the pipe material in a pipe axial direction; and
performing bending and bending back processing in a pipe circumferential direction as cold processing on a pipe after the hot rolling, wherein
a pipe length LF [mm] after the hot rolling, a pipe length LP [mm] after the piercing rolling, and an amount of traveling X [mm] in a rolling direction of the pipe in one rotation of the pipe during the piercing rolling satisfy the following formula (2);
( LF/LP )× X ≤1100 [mm] . . . .   Formula (2).

16. A method for manufacturing the seamless pipe according to claim 2 , the method comprising:
performing piercing of a pipe material by hot rolling, while rotating the pipe material and advancing the pipe material in a pipe axial direction; and
performing bending and bending back processing in a pipe circumferential direction as cold processing on a pipe after the hot rolling, wherein
a pipe length LF [mm] after the hot rolling, a pipe length LP [mm] after the piercing rolling, and an amount of traveling X [mm] in a rolling direction of the pipe in one rotation of the pipe during the piercing rolling satisfy the following formula (2);
( LF/LP )× X ≤1100 [mm] . . . .   Formula (2).

17. A method for manufacturing the seamless pipe according to claim 3 , the method comprising:
performing piercing of a pipe material by hot rolling, while rotating the pipe material and advancing the pipe material in a pipe axial direction; and
performing bending and bending back processing in a pipe circumferential direction as cold processing on a pipe after the hot rolling, wherein
a pipe length LF [mm] after the hot rolling, a pipe length LP [mm] after the piercing rolling, and an amount of traveling X [mm] in a rolling direction of the pipe in one rotation of the pipe during the piercing rolling satisfy the following formula (2);
( LF/LP )× X ≤1100 [mm] . . . .   Formula (2).

18. A method for manufacturing the seamless pipe according to claim 4 , the method comprising:
performing piercing of a pipe material by hot rolling, while rotating the pipe material and advancing the pipe material in a pipe axial direction; and
performing bending and bending back processing in a pipe circumferential direction as cold processing on a pipe after the hot rolling, wherein
a pipe length LF [mm] after the hot rolling, a pipe length LP [mm] after the piercing rolling, and an amount of traveling X [mm] in a rolling direction of the pipe in one rotation of the pipe during the piercing rolling satisfy the following formula (2);
( LF/LP )× X ≤1100 [mm] . . . .   Formula (2).

19. A method for manufacturing the seamless pipe according to claim 5 , the method comprising:
performing piercing of a pipe material by hot rolling, while rotating the pipe material and advancing the pipe material in a pipe axial direction; and
performing bending and bending back processing in a pipe circumferential direction as cold processing on a pipe after the hot rolling, wherein
a pipe length LF [mm] after the hot rolling, a pipe length LP [mm] after the piercing rolling, and an amount of traveling X [mm] in a rolling direction of the pipe in one rotation of the pipe during the piercing rolling satisfy the following formula (2);
( LF/LP )× X ≤1100 [mm] . . . .   Formula (2).

20. A method for manufacturing the seamless pipe according to claim 7 , the method comprising:
performing piercing of a pipe material by hot rolling, while rotating the pipe material and advancing the pipe material in a pipe axia

Assignees

• Jfe Steel Corp

Inventors

• Sasaki Shunsuke
• Yuga Masao
• Katsumura Tatsuro
• Kijima Hideo

Classifications

• C21D8/10

  during manufacturing of tubular bodies · CPC title

• F16L15/001

  with conical threads · CPC title

• B21B19/06

  Rolling hollow basic material, {e.g. Assel mills}(B21B19/04 takes precedence; separating work from mandrel B21C45/00) · CPC title

• B21B37/78

  Control of tube rolling · CPC title

• B21B38/04

  for measuring thickness, width, diameter or other transverse dimensions of the product · CPC title