ULTRASONIC TESTING METHOD AND EQUIPMENT THEREFOR

• US 20110113885A1
• Filed: 03/24/2009
• Published: 05/19/2011
• Est. Priority Date: 03/27/2008
• Status: Active Grant

• Current Assignee: Nippon Steel Corporation
• Original Assignee: Sumitomo Metal Industries Limited (Nippon Steel Corporation)
• Inventors: Yamano, Masaki, Ueda, Yoshio, Ikeda, Masami
• Granted Patent: US 8,413,513 B2
• Time in Patent Office: Days
• US Class Current: 73/632
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 2291/2632 flat
• CPC Class Codes: G01N 29/069 Defect imaging, localisation and sizing using, e.g. time of flight diffraction [TOFD], synthetic aperture focusing technique [SAFT], Amplituden-Laufzeit-Ortskurven [ALOK] technique
• CPC Class Codes: G01N 29/262 by electronic orientation or focusing, e.g. with phased arrays phased arrays per se G10K11/34
• CPC Class Codes: G01N 29/265 by moving the sensor relative to a stationary material

Abstract

An ultrasonic testing equipment includes a linear array ultrasonic probe in which a plurality of transducers are arranged in a direction orthogonal to the rolling direction of a test object and a signal processing unit. The signal processing unit executes following (1) to (6). (1) Generating an aperture synthetic image of testing signals of each section of the test object. (2) Generating a maximum value distribution of testing signals in the arrangement direction of transducers. (3) Calculating the width of a defect in each section based on the maximum value distribution. (4) Generating a maximum value distribution of the testing signals in the rolling direction based on the maximum value distribution of a plurality of sections of the test object. (5) Calculating the length of the defect based on the maximum value distribution of the testing signals in the rolling direction. (6) Calculating the area of the defect based on the calculated defect length and the calculated defect width of each section.

Claims

1. An ultrasonic testing method comprising the steps of:

disposing a linear array ultrasonic probe in which a plurality of transducers are arranged in a direction orthogonal to the rolling direction of a test object such that it is opposed to the test object;

moving the ultrasonic probe in the rolling direction of the test object relative to the test object; and

calculating the area of a defect existing in the test object based on testing signals output from the ultrasonic probe, wherein

the step of calculating the area of the defect includes;

a first step of performing aperture synthetic processing on testing signals output from the ultrasonic probe so as to generate an aperture synthetic image of the testing signals about each section of the test object in the direction opposed to the ultrasonic probe;

a second step of extracting a maximum value of the testing signals in the opposed direction from the aperture synthetic image so as to generate a maximum value distribution of the testing signals in the arrangement direction of the transducers;

a third step of calculating both ends in the width direction of the defect in each section of the test object, based on the maximum value distribution of the testing signals in the arrangement direction of the transducers so as to calculate the width of the defect in each section of the test object based on the calculated distance between the both ends;

a fourth step of generating a maximum value distribution of the testing signals in the rolling direction, based on the maximum value distribution of the testing signals in the arrangement direction of the transducers in a plurality of sections of the test object;

a fifth step of calculating the length of the defect based on the maximum value distribution of the testing signals in the rolling direction generated in the fourth step; and

a sixth step of calculating the area of the defect based on the length of the defect calculated in the fifth step and the width of the defect in each section calculated in the third step.

2. An ultrasonic testing equipment comprising:

a linear array ultrasonic probe disposed to be opposed to a test object and movable in the rolling direction of the test object relative to the test object, in which a plurality of transducers are arranged in a direction orthogonal to the rolling direction; and

a signal processing unit for calculating the area of a defect existing in the test object based on testing signals output from the ultrasonic probe, wherein

the signal processing unit executes;

a first step of performing aperture synthetic processing on testing signals output from the ultrasonic probe so as to generate an aperture synthetic image of the testing signals about each section of the test object in the direction opposed to the ultrasonic probe;

a second step of extracting a maximum value of the testing signals in the opposed direction from the aperture synthetic image so as to generate a maximum value distribution of the testing signals in the arrangement direction of the transducers;

a third step of calculating both ends in the width direction of the defect in each section of the test object, based on the maximum value distribution of the testing signals in the arrangement direction of the transducers so as to calculate the width of the defect in each section of the test object based on the calculated distance between the both ends;

a fourth step of generating a maximum value distribution of the testing signals in the rolling direction, based on the maximum value distribution of the testing signals in the arrangement direction of the transducers in plurality of sections of the test object;

a fifth step of calculating the length of the defect based on the maximum value distribution of the testing signals in the rolling direction generated in the fourth step; and

a sixth step of calculating the area of the defect based on the length of the defect calculated in the fifth step and the width of the defect in each section calculated in the third step.