1 Scope
This standard specifies techniques for the manual ultrasonic testing of fusion-welded joints in metallic materials with thickness greater than or equal to 8 mm which exhibit low ultrasonic attenuation (especially that due to scatter) at object temperatures from 0℃ to 60℃. It is primarily intended for use on full penetration welds where both the welded and parent material are ferritic.
Material-dependent ultrasonic values are specified in this standard, they are based on steels having an ultrasonic sound velocity of (5920 ± 50) m/s for longitudinal waves and (3255 ± 30) m/s for transverse waves.
This standard specifies four testing levels, each corresponding to a different probability of detection of imperfections. Guidance on the selection of testing levels A, B and C is given in Annex A.
This standard specifies that the requirements of testing level D, which is intended for special applications, be in accordance with general requirements. Testing level D can only be used when defined by specification. This includes tests of metals other than ferritic steel, tests on partial penetration welds, tests with automated equipment, and tests at object temperatures outside the range 0℃ to 60℃.
This standard can be used for the assessment of indications, for acceptance purposes, by either of the following techniques:
a) assessment based primarily on length and echo amplitude;
b) assessment based on characterization and sizing of the indication by probe movement techniques.
The techniques used shall be specified.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 5616 "Non-destructive Testing - Guidelines for Application"
GB/T 9445 "Non-destructive Testing - Qualification and Certification of Personnel" (GB/T 9445-2008, ISO 9712: 2005, IDT)
GB/T 12604.1 "Terminology for Nondestructive Testing - Ultrasonic" (GB/T 12604.1-2005, ISO 5577: 2000, IDT)
GB/T 19418 "Arc-welded Joints in Steel - Guidance on Quality Levels for Imperfections" (GB/T 19418-2003, ISO 5817: 1992, IDT)
GB/T 19799.1 "Non-destructive Testing - Ultrasonic Testing - Calibration Block No.1" (GB/T 19799.1-2005, ISO 2400: 1972, IDT)
GB/T 19799.2 "Non-destructive Testing - Ultrasonic Testing - Specification for Calibration Block No.2" (GB/T 19799.2-2012, ISO 7963: 2006, IDT)
GB/T 23905 "Non-destructive Testing - Blocks for Ultrasonic Testing"
GB/T 29711 "Non-destructive Testing of Welds - Ultrasonic Testing - Characterization of Indications in Welds" (ISO 23279: 2010, IDT)
GB/T 29712 "Non-destructive Testing of Welds - Ultrasonic Testing - Acceptance Levels" (ISO 11666: 2010, MOD)
JB/T 9214 "Non-destructive Testing - Practice for Evaluating Performance Characteristics of A Scope Ultrasonic Pulse - Echo Testing Systems"
JB/T 10061 "Commonly used Specification for A-mode Ultrasonic Flaw Detector Using Pulse Echo Technique"
3 Terms, Definitions and Symbols
3.1 For the purposes of this standard, the terms and definitions given in GB/T 12604.1 apply.
3.2 For symbols, their definitions, and units, see Table 1.
Indications shall be considered to be either longitudinal or transverse, depending on the direction of their dimension with respect to the weld axis, x, in accordance with Figure 3.
Foreword I
1 Scope
2 Normative References
3 Terms, Definitions and Symbols
4 Principle
5 Information Required Prior to Testing
6 Requirements for Personnel and Equipment
7. Testing Volume
8. Scanning Zone
9. Parent Metal Testing
10. Time Base and Sensitivity Setting
11. Testing Levels
12. Testing Techniques
13. Testing Report
Annex A (Normative) Testing Levels for Various Types of Welded Joints
Annex B (Normative) Tandem Testing
The transfer and attenuation loss shall be corrected in the sensitivity setting. In addition, the sensitivity shall be compensated in case of reduction due to the side wall interferance. The sensitivity correction is set by 6dB method or measurement of the disk-shaped reflector at the edge of testing volume.Annex C (Informative) Technical Parameters of Equipment
Annex D (Normative) Calculation of Actual Refraction Angle of Curved Surface Parts
Annex E (Normative) Setting of Time Base and Sensitivity
Annex F (Normative) Transmission Correction
