GB/T 8651-2015Metal plates—Flaw detection method by the ultrasonic plate wave (English PDF)

1 Scope

This Standard specifies the terms, definitions, general requirements, flaw detection equipment, contrast sample, selection of plate wave mode, flaw detection method and flaw assessment of flaw detection method by the ultrasonic plate wave for metal plates.

This Standard is applicable to flaw detection by the ultrasonic plate wave for metal plates whose thickness is not more than 5 times of the surface wavelength of detected plates. However, it must be confirmed that the stimulated sound wave is plate wave, and flaw detection can be conducted under sufficient sensitivity of flaw detection.

2 Normative References

The following documents are indispensable to the application of this Standard. In terms of references with a specified date, only versions with a specified date are applicable to this Standard. The latest version (including all the modifications) of references without a specified date is also applicable to this Standard.

GB/T 9445 Non-destructive Testing - Qualification and Certification of Personnel

GB/T 12604.1 Non-destructive Testing - Terminology - Terms Used in Ultrasonic Testing

JB/T 10061 Commonly Used Specification for A-mode Ultrasonic Flaw Detector Using Pulse Echo Technique

3 Terms and Definitions

Those defined in GB/T 12604.1, and the following terms and definitions are applicable to this Standard.

4 General Requirements

4.1 Flaw detection by plate wave can be conducted with piezoelectric transducer or electromagnetic acoustic transducer. No matter which type of transducer is adopted, the sensitivity of flaw detection shall be guaranteed. The center frequency of transducer shall be consistent with the frequency of the emission and reception unit of detection equipment.

4.2 Detected plate shall manifest uniform thickness, smooth and flat surface; there shall be no liquid drops, oil stains, corrosion or other dirt.

4.3 Metallographic structure of detected plate shall not generate interference echo that might affect flaw detection during flaw detection.

4.4 The site of flaw detection shall avoid factors that might affect the stability of ultrasonic flaw detector or the reliable observation of flaw detectors, such as strong light, strong magnetic field, strong vibration, corrosive gas or severe dust, etc.

4.5 Flaw detectors shall have specialized knowledge on flaw detection by plate wave; flaw defectors shall obtain Ultrasonic Detection Qualification Certificate (Level-1 or above) in accordance with GB/T 9445. Issuers of flaw detection reports shall obtain Ultrasonic Detection Qualification Certificate (Level-2 or above).

5 Flaw Detection Equipment

5.1 The incident angle of piezoelectric probe chip shall maintain consistent, which can reduce the stimulation of unnecessary plate wave mode.

5.2 The performance of flaw detector shall comply with the requirements in JB/T 10061.

5.3 The other parts of flaw detection equipment, for example, transmission mechanism, shall guarantee the reliability and repeatability of the result of flaw detection.

6 Contrast Sample

6.1 Contrast sample shall be adopted to adjust the sensitivity of flaw detection system.

6.2 Contrast sample shall have the identical nominal thickness, identical or similar surface state, technological conditions and acoustic performance as detected plate; there shall be no internal natural macroscopic defects that might affect flaw detection.

6.3 Contrast sample shall be cut from finished plate; its long side shall be perpendicular

8 Flaw Detection Method and Flaw Assessment

9 Flaw Detection Record and Report

9.1 Flaw detection record shall at least include the following main content.

a) Texture (or steel plate number) of detected steel plate, plate material number, plate material specification, and number of flaw detection standard; […]