NB/T 47013.10-2015Nondestructive testing of pressure equipments - Part 10: Ultrasonic time of flight diffraction technique (English PDF)

Foreword

This Standard "Nondestructive Testing of Pressure Equipments" (NB/T 47013) comprises the following 13 parts.

- Part 1. General Requirements;

- Part 2. Radiographic Testing;

- Part 3. Ultrasonic Testing;

- Part 4. Magnetic Particle Testing;

- Part 5. Penetrant Testing;

- Part 6. Eddy Current Testing;

- Part 7. Visual Testing;

- Part 8. Leak Testing;

- Part 9. Acoustic Emission Testing;

- Part 10. Ultrasonic Time of Flight Diffraction Technique;

- Part 11. Standard Practice for X-ray Digital Radioscopy;

- Part 12. Magnetic Flux Leakage Testing;

- Part 13. Pulsed Eddy Current Testing.

This Part is Part 10 of NB/T 47013. Ultrasonic Time of Flight Diffraction Technique.

This Part was drafted according to the rules given in "Directives for Standardization - Part 1. Structure and Drafting of Standards" (GB/T 1.1-2009). This Part supersedes "Nondestructive Testing of Pressure Equipments - Part10.

Ultrasonic Time of Flight Diffraction Technique" (NB/T 47013.10-2010); compared with NB/T 47013.10-2010, this Part has the following main technical changes.

- The relevant content of the chapter "Scope" was modified;

- Normative references were modified;

- Terminologies and definitions were added;

- Sequence of parts of the chapters and sections was adjusted;

- Testing standards, testing requirements and testing parameters of testing instrument and probe were specified;

- The quantity of reference blocks was reduced, and the requirements of reference blocks given in the former standard were kept;

- The test blocks for height of scanning surface dead zone and spread angle of sound beam were added;

- The use and operating requirements of simulating test block were adjusted;

- The requirements for calibration, checking, operation checking and inspection of testing equipments and apparatuses were added;

- The requirements for the technical level of TOFD testing were added, and suggestions on selection of testing methods for scanning surface dead zone, back wall dead zone and transverse flaw were provided;

- Safety requirements were added;

- The requirements of testing area were modified;

- Part of content in "selection of scanning mode" was adjusted;

- The determination method of dead zone height was added;

- The requirements of "confirmation of overall setting of testing system" were added;

- Part of content in quality classification was modified;

- The requirements of testing records were added;

- Informative Appendix A - "Testing of Workpieces with Unequal Thickness" was added;

- Informative Appendix C - "Measurement Method of the -12dB Sound Beam Spread Angle of Instrument and Probe Combination" was added;

- Informative Appendix E - "Typical TOFD Images" was added.

1 Scope

1.1 This Part of NB/T 47013 specifies the methods and quality classification requirements of ultrasonic time of flight diffraction technique (hereinafter referred to as "TOFD") adopted for pressure equipments.

1.2 This Part is applicable to such welded joints meeting the following conditions at the same time.

a) The material is low carbon steel or low alloy steel;

b) Butt joint of full-penetration structure type;

c) Nominal thickness of workpiece, t. 12mm<=t<=400mm (excluding weld reinforcement; when the base metal on both sides of weld is different, the nominal thickness of the thinner side shall be taken).

1.3 As for the stainless steel-steel clad plate, titanium-steel clad plate, aluminum-steel clad plate and nickel-steel clad plate used for such pressure equipments with the nominal thickness of base metal (of low carbon steel or low alloy steel) greater than or equal to 12mm, TOFD testing over the butt joint of base metal carried out from the side of base metal may refer to this Part; if TOFD testing over the butt joint of base metal is carried out from the side of cladding metal, it may also refer to this Part, but the area where ultrasonic sound beam may pass through shall be tested with normal probe according to the requirements of NB/T 47013.3 and it shall be free from any unbonding with flat bottom hole equivalent diameter greater than or equal to phi2mm.

1.4 As for the pressure equipments with the nominal thickness of base metal (of low carbon steel or low alloy steel) greater than or equal to 12mm and with clad layer of austenitic stainless steel, nickel alloy or other materials, the TOFD testing over the butt joint of base metal carried out from the side of base metal may refer to this Part.

1.5 As for the support members and structural members relevant to pressure equipments, the TOFD testing may refer to this Part; as for metallic materials with isotropic fine grain and low acoustic attenuation, the TOFD testing may also refer to this Part, but the change of acoustic characteristics shall be considered; as for the fillet joint of insertion type connection pipe, the TOFD testing may refer to this Part when the testing conditions required in this Part are met.

1.6 When the nominal thickness of base metal on both sides of welded joint is unequal, the testing may be carried out by making reference to Appendix A.

2 Normative References

The following documents for the application of this document are essential. Any dated reference, just dated edition applies to this document. For undated references, the latest edition (including any amendments) applies to this document.

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

GB/T 27664.1 Non-destructive Testing - Characterization and Verification of Ultrasonic Test Equipment - Part 1. Instruments

GB/T 27664.2 Non-destructive Testing - Characterization and Verification of Ultrasonic Test Equipment - Part 2. Probes

NB/T 47013.1 Nondestructive Testing of Pressure Equipments-Part 1. General Requirements

NB/T 47013.2 Nondestructive Testing of Pressure Equipments-Part 2. Radiographic Testing

NB/T 47013.3 Nondestructive Testing of Pressure Equipments- Part 3. Ultrasonic Testing

NB/T 47013.4 Nondestructive Testing of Pressure Equipments-Part 4. Magnetic Particle Testing

NB/T 47013.5 Nondestructive Testing of Pressure Equipments-Part 5. Penetrant Testing

NB/T 47013.6 Nondestructive Testing of Pressure Equipments-Part 6. Eddy Current Testing

JB/T 8428 Non-destructive Testing - General Specification for Ultrasonic Test Block

JB/T 9214 Non-destructive Testing - Test Methods for Evaluating Performance Characteristics of A-scan Pulse-echo Ultrasonic Testing Systems

JB/T 10062 Testing Methods for Performance of Probes Used in Ultrasonic Flaw Detection

3 Terminologies and Definitions

For the purpose of this Part, the terminologies and definitions defined in GB/T 12604.1 and NB/T 47013.1 as well as the following ones apply.