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GB/T 34370.12-2024Nondestructive testing of amusement equipments - Part 12: Phase-array ultrasonic testing methods for bolts (English PDF)

游乐设施无损检测第12部分：螺栓相控阵超声检测

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Issued by

SAMR; SAC

Level / Type

National · Recommended

Issue date

August 23, 2024

Implementation date

December 1, 2024

Scope

GB/T 34370.12-2024 is the English-translated version of 游乐设施无损检测第12部分：螺栓相控阵超声检测.

GB/T 34370.12-2024 is Part 12 of the Chinese series on non-destructive testing of amusement equipment, and gives the phased array ultrasonic method for bolts. Amusement rides are special equipment in China, inspected on a fixed cycle, and a fatigue crack in a structural bolt is one of the few failures that can drop a car full of people; the bolt cannot usually be removed, so the crack has to be found through the head, in place. Phased array makes that practical by steering the beam down the shank and imaging the reflectors. The standard describes the testing principle, the safety and personnel requirements, the equipment - the instrument, the probes, the combined system performance, the reference blocks and the couplant - and the testing and evaluation of crack indications. It applies to steel bolts of 10 to 100 mm outside diameter and up to 1000 mm long, and took effect on 1 December 2024.

Document preview — GB/T 34370.12-2024

National Standard of the People's Republic of China

ICS: 97.200.40
Classification: Y 57

Issued by: State Administration for Market Regulation; Standardization Administration of the PRC

3 Introduction...5
1 Scope...7
2 Normative References...7
3 Terms and Definitions...8
4 Principle of Testing...8
5 Safety Requirements...9
6 Personnel Requirements...9
7 Testing Equipment and Instruments...10
7.1 Basic requirements...10
7.2 Testing instruments...10
7.3 Probe...10
7.4 System combination performance of ultrasonic testing instrument and probe...11
7.5 Test blocks...12
7.6 Coupling agent...12
8 Testing and Evaluation...12
8.1 General testing process...12
8.2 Test process card...13
8.3 Preparation before testing...13
8.4 Implementation of testing...14
8.5 Evaluation...14
9 Test Records and Reports...15
9.1 Test records...15

1 Scope

This Document describes the phase-array ultrasonic testing and result evaluation method for crack defects in bolts of amusement facilities. This Document is applicable to the in-situ ultrasonic testing of steel bolts with an outer diameter of no less than 10 mm and no more than 100 mm and a length of no more than 1 000 mm for amusement facilities. The phase-array ultrasonic testing of steel bolts and shafts (pins) for amusement facilities, cableways and other mechanical equipment shall be implemented as a reference.

2 Normative References

The provisions in following documents become the essential provisions of this Document through reference in this Document. For the dated documents, only the versions with the dates indicated are applicable to this Document; for the undated documents, only the latest version (including all the amendments) is applicable to this Document.

GB/T 12604.1 Non-destructive testing - Terminology - Terms used in ultrasonic testing

GB/T 20306 Amusement devices terminology

GB/T 34370.1 Nondestructive testing of amusement equipment - Part 1: General requirement

GB/T 34370.5 Nondestructive testing of amusement equipment - Part 5: Ultrasonic testing

GB/T 41114 Non-destructive testing - Ultrasonic testing - Specification for a calibration block for phased array testing (PAUT)

GB/T 42399.1 Non-destructive testing instruments - Characterization and verification of ultrasonic phased array equipment - Part 1: Instruments

GB/T 42399.2 Non-destructive testing instruments - Characterization and verification of ultrasonic phased array equipment - Part 2: Probes

GB/T 42399.3 Non-destructive testing instruments - Characterization and verification of ultrasonic phased array equipment - Part 3: Combined system

3 Terms and Definitions

For the purposes of this Document, the terms and definitions given in GB/T 12604.1, GB/T 20306, GB/T 34370.1, GB/T 34370.5 and the following terms and definitions apply.

3.1 Circumferential planar array A plurality of wafers on the same plane are arranged circumferentially to form a single-layer annular planar array probe.

3.2 Circumferential scan The scanning method that the aperture center of the excitation sound beam steps around the center of the probe; and the sound beam is dynamically focused on the sound beam of the corresponding cylindrical busbar.

3.3 Cylindrically B-scan view The sound field image formed on the circular section parallel to the sound beam and perpendicular to the scanning surface of the cylindrical workpiece under test is displayed in a color or grayscale manner to represent the amplitude of the ultrasonic signal.

3.4 Circumferential C-scan view The sound field image formed on the cross section parallel to the bolt scanning surface is displayed in color or grayscale to represent the amplitude of the ultrasonic signal within the preset time window.

4 Principle of Testing

According to the set delay law, some array elements of the circumferential planar array probe are excited. The synthetic sound beam has the functions of radial small-angle deflection, circumferential focusing and continuous scanning of the sound beam. The ultrasonic signal received by each array element is then processed in a circumferential scanning manner according to the same delay law or dynamic focusing, and the discontinuous information inside the bolt is displayed by A-scan, cylindrical B-scan or circumferential C-scan, as shown in Figure 1.

7.1 Basic requirements

7.1.1 Ultrasonic testing equipment shall at least include probe, phase-array ultrasonic detector, standard test block, comparison test block, coupling agent. If there are rust stains or raised lettering on the tested surface, grinding tools shall be prepared.

7.1.2 The probe, phase-array ultrasonic detector, standard test block, and comparison test block in the ultrasonic testing equipment shall have a product quality certificate or qualified certification documents.

7.1.3 The calibration, verification, periodic verification, and inspection of ultrasonic testing equipment and instruments shall be carried out in accordance with the requirements of GB/T 34370.1 and GB/T 34370.5.

7.2 Testing instruments In addition to meeting the requirements of GB/T 42399.1, ultrasonic detectors shall also meet the following requirements:

a) The measured value of the transmitted pulse repetition frequency of the phase-array ultrasonic detector shall not exceed 10% from the nominal value; the measured value of the transmitted pulse voltage shall not exceed 20% from the nominal value; the measured value of the transmitted pulse width shall not exceed 10% from the nominal value; and the transmit pulse rise time shall be less than

0.25 times the nominal frequency cycle time of the highest probe that may be used;

b) The operating frequency of the phase-array ultrasonic detector shall be measured at -3 dB and include at least a range of

0.5 MHz to 15 MHz; and the error between the measured value and the nominal value of the upper and lower limits of each frequency band shall not exceed 10%;

c) The phase-array ultrasonic detector shall have no less than 16/64 receiving excitation channels and shall have a circumferential scanning function;

d) The gain range is 0 dB to 80 dB; and the minimum adjustment step is no greater than

0.5 dB;

e) The scanned image has A-scan view, cylindrically B-scan view, and circumferential C- scan view functions.

7.3 Probe In addition to meeting the requirements of GB/T 42399.2, the phase-array probe shall also meet the following requirements.

a) The ultrasonic phase-array detection probe shall be a circumferential planar array probe, and shall also include a linear array probe.

7.4 System combination performance of ultrasonic testing instrument and probe

7.4.1 In addition to meeting the requirements of GB/T 42399.3, the system combination performance of ultrasonic testing instrument and probe shall also meet the following requirements:

a) Vertical linearity: deviation is no greater than 5%;

b) Horizontal linearity: deviation is no greater than 1%;

c) Sensitivity margin: at the maximum detection sound range, when detecting a 1 mm artificial groove, the sensitivity margin is no less than 10 dB;

d) The probe frequency matches the instrument bandwidth, and the error is no greater than 10%;

e) Longitudinal resolution: when using a 5 MHz probe, it is no greater than 2 mm.

7.4.2 The system combination performance of the testing instrument and probe shall be measured in the following situations:

a) Newly purchased ultrasonic testing instruments and (or) probes;

b) After the testing instrument and probe have been repaired or the main components have been replaced; By manually adjusting the time gain compensation (TCG) curve, the echo height of the artificial groove at different sound paths on the bolt comparison block is adjusted to 80% of the screen height as the reference sensitivity; and then the gain 6 dB again as the detection sensitivity.

8.3.5 Use of coupling agent The coupling agent used during the test shall be the same as that used to measure the distance wave amplitude curve.

8 Testing and Evaluation...

8.3 Preparation before testing...

8.3.6 Probe position

8.3.6.1 The probe position shall be selected according to the structural form of the bolt according to the following requirements.

a) For bolts without center holes, when the length is less than or equal to the effective detection length, scanning shall be performed from one end; when the length is greater than the effective detection length, scanning shall be performed from both ends.

b) For bolts with center holes, scan from both ends, respectively.

8.3.6.2 For the tested area of the workpiece that can be covered by the probe sound field, a circumferential planar linear array probe shall be used and placed in the center for testing.

8.3.6.3 When the probe sound field cannot cover the tested area of the workpiece at one time, a linear array probe shall be used to manually scan circumferentially around the center of the bolt.

8.3.7 Sensitivity compensation Sensitivity compensation shall be performed in accordance with the requirements of GB/T 34370.5.

8.3.8 Surface treatment of bolts The test surface shall be treated to be free of rust and stains; and the raised engraving reinforcement shall be polished to

0.2 mm.

8.4 Implementation of testing The test shall be carried out when the equipment is stopped; and the test environment temperature shall be 5°C ~ 40°C. Scan the workpiece according to the requirements of 8.3.6, and record the test results after the coupling is stable.

8.5 Evaluation

8.5.1 Determination of defect indication length The defect indication length shall be determined by the half-wave height method (-6 dB method). Place the probe to find the strongest reflected wave of the defect; adjust the wave height to 80% of the screen height; move the cursor in the circumferential direction; and mark when the wave height drops to 40% of the screen height. Move the cursor in the opposite direction to the same position where the wave height drops to 40% of the screen height and mark it. The distance between the two marks is the defect indication length.

8.5.2 Defect evaluation If the maximum reflected wave amplitude is no less than the reference sensitivity and the indicated length is no less than 5 mm defect reflection wave amplitude, it shall be determined as a crack. If it is less than 5 mm, the defect nature is not determined; and it can also be further determined by disassembly or other non-destructive testing methods.

9 Test Records and Reports

9.1 Test records Test records shall record test data or information in accordance with the requirements of the test process regulations, and shall at least include the contents of the test report except the result evaluation.

9.2 Test report Ultrasonic test reports shall at least include the following contents:

a) Commissioning organization, test organization and report number;

b) Process specification version or test process card number;

c) Test execution standard;

d) Bolt name, number, material, surface condition;

e) Test equipment: instrument model and number, probe, test block, coupling agent;

f) Test process parameters: test range, scanning position (face, side, etc.), test ratio, test sensitivity, sensitivity compensation, etc.;

g) Test schematic diagram of test location, test area, and the location, size, echo amplitude, evaluation and distribution of the found defects;

h) The ultrasonic test area shall be indicated in the report; and if there are parts that cannot be detected due to geometric shape restrictions, they shall also be explained;

......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 19 pages — is available in the English PDF.

Referenced standards

Normative references

GB/T 12604.1 · GB/T 41114 · GB/T 42399.1 · GB/T 42399.2 · GB/T 42399.3

Similar standards

GB 38031-2025|GB/T 12604.1|GB/T 20306|GB/T 34370.1|GB/T 34370.5|GB/T 41114|GB/T 42399.1|GB/T 42399.2

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