Ultrasonic Testing System and Ultrasonic Testing Technique for Pipe Member

• US 20090151457A1
• Filed: 11/21/2006
• Published: 06/18/2009
• Est. Priority Date: 11/21/2005
• Status: Active Grant

• Current Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Original Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Inventors: Iizuka, Yukinori
• Granted Patent: US 7,779,694 B2
• Time in Patent Office: Days
• US Class Current: 73/622
• CPC Class Codes: G01N 2291/0234 Metals, e.g. steel
• CPC Class Codes: G01N 2291/0421 Longitudinal waves
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/0428 Mode conversion
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 2291/2634 cylindrical from outside
• CPC Class Codes: G01N 2291/2675 Seam, butt welding
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/221 Arrangements for directing or focusing the acoustical waves electronic orientation or focusing G01N29/262; sound directing or focusing G10K11/26; mechanical steering of sound transducers or their beams G10K11/35

Abstract

Disclosed are an ultrasonic testing system and an ultrasonic testing technique for a pipe member capable of detecting minute flaws of several hundreds of microns or less located at positions in the wall thickness inside portion of a welded portion of a seam-welded pipe and the like without omission and further easily setting optimum conditions when the size of the pipe is changed. A transmitting beam, which is focused to the welded portion at an oblique angle, is transmitted using a part of the group of transducer elements of a linear array probe as a group of transducer elements for transmission, a receiving beam, which is focused at the focusing position of the transmitting beam at an oblique angle, is formed using the transducer elements of a portion different from the above group of transducer elements for transmission as a group of transducer elements for reception, and a flaw echo is received from the welded portion.

Claims

1. An ultrasonic testing system for a pipe member characterized by comprising:

a transmitting/receiving unit having a transmitting unit, which transmits an ultrasonic wave to the welded surface of a welded portion in a pipe axis direction of a pipe member and to the inside surface of the pipe member so that the ultrasonic wave is incident at an angle within the range from 33.2°

to 56.8°

, respectively, and a receiving unit, which partly or entirely receives an echo reflected in a direction within the range from −

12°

to 16°

to the mirror reflecting direction in the welded surface, wherein the transmitting unit and the receiving unit are composed of different groups of transducer elements on one, two, or more array probes disposed in a pipe member peripheral direction; and

a controller for scanning the pipe member in a thickness direction by carrying out a control to change the groups of transducer elements corresponding to the transmitting unit and the receiving unit on the array probe or to change the angle of the array probe as well as controlling the angle of incidence of the ultrasonic wave to the pipe member in the respective transmitting and receiving waves so that the angles of incidence to the welded surface and the inside surface and the angle of the echo on the welded surface are kept within the ranges defined as to the transmitted wave and the received wave, respectively.

2. An ultrasonic testing system for a pipe member according to claim 1, characterized in that the controller controls an angle of incidence to the pipe member and a focus position by offsetting at least one of timing of wave transmission and timing of wave reception of the respective transducer elements in the group of transducer elements so that the angles of incidence to the welded surface and the inside surface and the angle of the echo on the welded surface are kept within the defined ranges, respectively.

3. An ultrasonic testing system for a pipe member according to claim 1, characterized in that the angle of incidence of at least one of the ultrasonic wave on the transmitting side or the ultrasonic wave on the receiving side to the pipe member is kept to a predetermined angle.

4. An ultrasonic testing system for a pipe member according to claim 3, characterized in that the controller controls at least one of the wave transmitted from or received by the respective transducer elements so that the angle of incidence of the ultrasonic wave to the pipe member is made to a predetermined angle.

5. An ultrasonic testing system for a pipe member according to claim 4, characterized in that the controller controls the angle of incidence to the pipe member and the focus position by offsets at least one of timing of wave transmission and timing of wave reception of the respective transducer elements in the group of transducer elements based on a curvature of the pipe member.

6. An ultrasonic testing system for a pipe member according to claim 3, characterized in that the array probe provides the group of transducer elements with a curvature so that they are disposed along the peripheral direction of the pipe member.

7. An ultrasonic testing system for a pipe member according to claim 1, characterized in that at least one of the transmitting unit or the receiving unit transmits an ultrasonic wave having a focusing coefficient of 5 dB or more to 50 dB or less.

8. An ultrasonic testing system for a pipe member according to claim 1, characterized in that the array probe includes an acoustical lens for focusing the transmitting beam and the receiving beam in the pipe axis direction of the pipe member, and the focal length of the acoustical lens is set shorter as it is nearer to the welded portion and longer as it is farther from the welded portion.

9. An ultrasonic testing system for a pipe member according to claim 1, characterized in that the transmitting/receiving unit comprises a plurality of array probes as well as includes a transmitting unit and a receiving unit on each array probe.

10. An ultrasonic testing system for a pipe member according to claim 1, characterized in that the transmitting unit and the receiving unit of the transmitting/receiving unit comprises different array probes.

11. An ultrasonic testing system for a pipe member according to claim 1, characterized in that:

the transmitting unit and the receiving unit of the transmitting/receiving unit comprises different array probes; and

the controller changes the deflection angles of the transmitting beams and the receiving beams from the respective array probes.

12. An ultrasonic testing system for a pipe member according to claim 1, characterized in that the controller changes the angle of incidence and the focus position of the ultrasonic wave to the pipe member in at least one of the transmitting wave or the receiving wave so that the scanning lines of the transmitting beam intersect the scanning lines of the receiving beam at a plurality of positions.

13. An ultrasonic testing technique for a pipe member, characterized in that the ultrasonic testing technique uses an ultrasonic testing system for a pipe member comprising a transmitting unit and a receiving unit composed of different groups of transducer elements on one, two, or more array probes disposed in a pipe member peripheral direction and comprises:

transmitting an ultrasonic wave to the welded surface of a welded portion in a pipe axis direction of the pipe member and to the inside surface of the pipe member by the transmitting unit so that the ultrasonic wave is incident at an angle within the range from 33.2°

to 56.8°

, respectively;

partly or entirely receiving an echo reflected in a direction within the range from −

12°

to 16°

to the mirror reflecting direction in the welded surface; and

scanning the pipe member in a thickness direction by carrying out a control to change the groups of transducer elements corresponding to the transmitting unit and the receiving unit on the array probe or to change the angle of the array probe.

14. An ultrasonic testing technique for a pipe member according to claim 13, characterized by comprising controlling the angle of incidence to the pipe member and a focus position by offsetting at least one of timing of wave transmission or timing of wave reception of the respective transducer elements in the group of transducer elements.

15. An ultrasonic testing technique for a pipe member according to claim 13, characterized by comprising keeping the angle of incidence of at least one of the ultrasonic wave on the transmitting side or the ultrasonic wave on the receiving side to the pipe member is kept to a predetermined angle.

16. An ultrasonic testing technique for a pipe member according to claim 13, characterized in that at least one of the transmitting unit or the receiving unit transmits an ultrasonic wave having a focusing coefficient of 5 dB or more to 50 dB or less.