1 Scope
1.1This 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.
1.2This 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).
1.3As 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 φ2mm.
1.4As 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
Foreword I
1 Scope
2 Normative References
3 Terminologies and Definitions
4 General Requirements
5 Selection and Setting of Testing Process Parameters
6 Testing
7 Analysis and Explanation of the Testing Data
8 Flaw Evaluation and Quality Classification
9 Testing Record and Report
Appendix A (Informative) Testing of Workpieces with Unequal Thickness
Appendix B (Normative) Requirements for Performance Indexes of TOFD Testing Instrument and Probe
Appendix C (Informative) Measurement Method of the -12 dB Sound Beam Spread Angle of Instrument and Probe Combination
Appendix D (Normative) Reference Blocks of Other Structure Types
Appendix E (Informative) Typical TOFD Images
