GB/T 8651-2015 Flaw detection method by the ultrasonic plate wave for metal plates
1 Scope
This standard specifies the terms and definitions, general requirements, flaw detection equipment, reference specimens, selection of plate wave modes, flaw detection methods, and defect evaluation for flaw detection method by the ultrasonic plate wave for metal plates.
This standard is applicable to the flaw detection by the ultrasonic plate wave for metal plates with a thickness of not greater than five times the surface wave wavelength of the plates being detected, provided that the excited acoustic waves are verified to be plate waves and that flaw detection can be carried out with sufficient sensitivity.
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 9445 Non-destructive testing - Qualification and certification of personnel
GB/T 12604.1 Non-destructive testing - Terminology - Ultrasonic testing
JB/T 10061 Commonly used specification for A-mode ultrasonic flaw detector using pulse echo technique
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 12604.1 and the following apply.
3.1
mode
relationship between the direction of particle displacement and the direction of propagation. For plate waves, the wave mode indicates how the particle displacement varies with respect to the plate center during acoustic propagation. Plate waves are classified into symmetric and antisymmetric types. The representation forms for plate waves of different types and orders: SH waves are typically represented as n0, n2, n4... (symmetric type) and n1, n3, n5... (antisymmetric type); Lamb waves are typically represented as S0, S1, S2... (symmetric type) and a0, a1, a2... (antisymmetric type)
4 General requirements
4.1 Flaw detection by ultrasonic plate wave may be performed using piezoelectric transducers or electromagnetic acoustic transducers. Regardless of the type of transducer used, the flaw detection sensitivity shall be ensured, and the center frequency of the transducer shall match the frequency of the transmitting and receiving units of the detection equipment.
4.2 The plate under detection shall be uniform in thickness, flat and smooth in surface, and shall be free of droplets, oil stains, corrosion, and other contaminants.
4.3 The metallographic structure of the plate under detection shall not produce interfering echoes that affect the flaw detection.
4.4 The flaw detection site shall be protected from strong light, high-intensity magnetic field, violent vibration, corrosive gas, heavy dust and other factors that affect the stability of ultrasonic flaw detector or reliable observation by flaw detection personnel.
4.5 The flaw detection personnel shall have specialized knowledge of plate wave flaw detection and shall obtain a qualification certificate of Level 1 or above in ultrasonic detection in accordance with GB/T 9445. Anyone issuing flaw detection reports shall obtain a qualification certificate of Level 2 or above in ultrasonic detection.
5 Flaw detection equipment
5.1 The incident angles of the piezoelectric probe crystals shall be as consistent as possible to minimize the excitation of unwanted plate wave modes.
5.2 The performance of the flaw detector shall meet the requirements of JB/T 10061.
5.3 Other parts of the flaw detection equipment, such as the transmission mechanism, shall ensure the reliability and repeatability of the flaw detection results.
6 Reference specimens
6.1 Reference specimens are used for sensitivity adjustment of the flaw detection system.
6.2 Reference specimens shall have the same nominal thickness, and the same or similar surface condition, process conditions, and acoustic properties as the plate under detection, and shall have no natural macroscopic defects that affect the flaw detection.
6.3 Reference specimens shall be cut from finished plates, with their long side perpendicular to the rolling direction, the end faces straight, and the thickness tolerance less than 2% of the plate thickness.
6.4 Reference specimens may be made by drilling or notching. The dimensions of the reference specimen may be reasonably determined based on the dimension of the plate to be inspected. For the inspection of large-sized whole steel plates, the short side of the reference specimen shall be 200mm, and the long side shall not be less than 500mm. The dimensions and shapes of the reference specimens are shown in Figure 1a), Figure 1b), Figure 1c), and Figure 1d). The through hole diameter in Figure 1a) shall meet those specified in Table 1.
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Flaw detection equipment
6 Reference specimens
7 Selection of plate wave modes
8 Flaw detection method and defect evaluation
9 Flaw detection record and report
Annex A (Informative) Lamb wave frequency equation and group velocity calculation equation under free boundary conditions
Annex B (Informative) Plate wave dispersion curves for 406 high-strength steel plate
Annex C (Informative) Plate wave dispersion curves for low carbon steel plate
Annex D (Informative) Plate wave dispersion curves for 1Cr13 material
Annex E (Informative) Plate wave dispersion curves for 1Cr18Ni9Ti material
Annex F (Informative) Plate wave dispersion curves for Cr17Ni2 material
Annex G (Informative) Plate wave dispersion curves for GH169 material
Annex H (Informative) Plate wave dispersion curves for TA2 material
Annex I (Informative) Plate wave dispersion curves for TA7 material
Annex J (Informative) Plate wave dispersion curves for TC2 material
Annex K (Informative) Plate wave dispersion curves for TC4 material
Annex L (Informative) Plate wave dispersion curves for 5A06 material
Annex M (Informative) Plate wave dispersion curves for 2A12 material
GB/T 8651-2015 Flaw detection method by the ultrasonic plate wave for metal plates
1 Scope
This standard specifies the terms and definitions, general requirements, flaw detection equipment, reference specimens, selection of plate wave modes, flaw detection methods, and defect evaluation for flaw detection method by the ultrasonic plate wave for metal plates.
This standard is applicable to the flaw detection by the ultrasonic plate wave for metal plates with a thickness of not greater than five times the surface wave wavelength of the plates being detected, provided that the excited acoustic waves are verified to be plate waves and that flaw detection can be carried out with sufficient sensitivity.
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 9445 Non-destructive testing - Qualification and certification of personnel
GB/T 12604.1 Non-destructive testing - Terminology - Ultrasonic testing
JB/T 10061 Commonly used specification for A-mode ultrasonic flaw detector using pulse echo technique
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 12604.1 and the following apply.
3.1
mode
relationship between the direction of particle displacement and the direction of propagation. For plate waves, the wave mode indicates how the particle displacement varies with respect to the plate center during acoustic propagation. Plate waves are classified into symmetric and antisymmetric types. The representation forms for plate waves of different types and orders: SH waves are typically represented as n0, n2, n4... (symmetric type) and n1, n3, n5... (antisymmetric type); Lamb waves are typically represented as S0, S1, S2... (symmetric type) and a0, a1, a2... (antisymmetric type)
4 General requirements
4.1 Flaw detection by ultrasonic plate wave may be performed using piezoelectric transducers or electromagnetic acoustic transducers. Regardless of the type of transducer used, the flaw detection sensitivity shall be ensured, and the center frequency of the transducer shall match the frequency of the transmitting and receiving units of the detection equipment.
4.2 The plate under detection shall be uniform in thickness, flat and smooth in surface, and shall be free of droplets, oil stains, corrosion, and other contaminants.
4.3 The metallographic structure of the plate under detection shall not produce interfering echoes that affect the flaw detection.
4.4 The flaw detection site shall be protected from strong light, high-intensity magnetic field, violent vibration, corrosive gas, heavy dust and other factors that affect the stability of ultrasonic flaw detector or reliable observation by flaw detection personnel.
4.5 The flaw detection personnel shall have specialized knowledge of plate wave flaw detection and shall obtain a qualification certificate of Level 1 or above in ultrasonic detection in accordance with GB/T 9445. Anyone issuing flaw detection reports shall obtain a qualification certificate of Level 2 or above in ultrasonic detection.
5 Flaw detection equipment
5.1 The incident angles of the piezoelectric probe crystals shall be as consistent as possible to minimize the excitation of unwanted plate wave modes.
5.2 The performance of the flaw detector shall meet the requirements of JB/T 10061.
5.3 Other parts of the flaw detection equipment, such as the transmission mechanism, shall ensure the reliability and repeatability of the flaw detection results.
6 Reference specimens
6.1 Reference specimens are used for sensitivity adjustment of the flaw detection system.
6.2 Reference specimens shall have the same nominal thickness, and the same or similar surface condition, process conditions, and acoustic properties as the plate under detection, and shall have no natural macroscopic defects that affect the flaw detection.
6.3 Reference specimens shall be cut from finished plates, with their long side perpendicular to the rolling direction, the end faces straight, and the thickness tolerance less than 2% of the plate thickness.
6.4 Reference specimens may be made by drilling or notching. The dimensions of the reference specimen may be reasonably determined based on the dimension of the plate to be inspected. For the inspection of large-sized whole steel plates, the short side of the reference specimen shall be 200mm, and the long side shall not be less than 500mm. The dimensions and shapes of the reference specimens are shown in Figure 1a), Figure 1b), Figure 1c), and Figure 1d). The through hole diameter in Figure 1a) shall meet those specified in Table 1.
Contents of GB/T 8651-2015
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Flaw detection equipment
6 Reference specimens
7 Selection of plate wave modes
8 Flaw detection method and defect evaluation
9 Flaw detection record and report
Annex A (Informative) Lamb wave frequency equation and group velocity calculation equation under free boundary conditions
Annex B (Informative) Plate wave dispersion curves for 406 high-strength steel plate
Annex C (Informative) Plate wave dispersion curves for low carbon steel plate
Annex D (Informative) Plate wave dispersion curves for 1Cr13 material
Annex E (Informative) Plate wave dispersion curves for 1Cr18Ni9Ti material
Annex F (Informative) Plate wave dispersion curves for Cr17Ni2 material
Annex G (Informative) Plate wave dispersion curves for GH169 material
Annex H (Informative) Plate wave dispersion curves for TA2 material
Annex I (Informative) Plate wave dispersion curves for TA7 material
Annex J (Informative) Plate wave dispersion curves for TC2 material
Annex K (Informative) Plate wave dispersion curves for TC4 material
Annex L (Informative) Plate wave dispersion curves for 5A06 material
Annex M (Informative) Plate wave dispersion curves for 2A12 material
