This standard specifies the general provisions, test requirements, artificial standard defect specimens, working sensitivity of flaw detectors, scrapping basis, records, etc. for ultrasonic flaw detection of solid porcelain strips with a diameter greater than 50mm and straight cylindrical porcelain sleeves with a wall thickness greater than 30mm. This standard is only applicable to the longitudinal ultrasonic flaw detection of porcelain parts by contact method using A-type pulse reflection ultrasonic flaw detector. JB/T 9674-1999 Ultrasonic detection of internal defects in porcelain parts JB/T9674-1999 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T 9674-1999
Ultrasonic Detection of Internal Defects of Porcelain Parts
1999-08-06 Issued
National Bureau of Machinery Industry
2000-01-01 Implementation
JB/T9674-1999
This standard is a revision of JB/Z262-86 "Ultrasonic Detection of Internal Defects of Porcelain Parts". The format and method of writing this standard conform to GB/T1.1--1993. This standard retains the technical content of JB/Z262-86. This standard adds the requirement of "non-destructive testing personnel must have a non-destructive testing personnel technical qualification certificate issued by the relevant national competent authorities" in accordance with the provisions of GB/T5616-1985 "Guidelines for the Application of Conventional Non-destructive Testing". This standard will replace JB/Z262-86 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Standardization of Insulators. The drafting unit of this standard is Xi'an Electric Ceramics Research Institute. The main drafters of this standard are Hu Shengbo and He Zhenglin. 1
1 Scope
Mechanical Industry Standard of the People's Republic of China
Ultrasonic detection of internal defects of porcelain parts
JB/T 9674-1999
Replaces JB/Z262-86
This standard specifies the general provisions, test requirements, artificial standard defect specimens, working sensitivity of flaw detectors, basis for scrapping, records, etc. for ultrasonic flaw detection of solid porcelain strips with a diameter greater than 50mm and straight cylindrical porcelain sleeves with a wall thickness greater than 30mm. This standard is only applicable to longitudinal ultrasonic flaw detection of porcelain parts using the contact method using a type A pulse reflection ultrasonic flaw detector. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of the standard, the versions shown are all valid. All standards will be revised. All parties using this standard should explore the possibility of using the latest version of the following standards. GB772-1987
Technical conditions for high-voltage insulator porcelain
GB/T2900.8-1995 Electrical terminology insulator GB/T5616-1985 Conventional non-destructive testing application guide 3 Definitions
In addition to complying with the provisions of GB/T2900.8, the definitions of terms used in this standard shall also adopt the following definitions. Ultrasonic testing ultrasonic testing
Use the directivity and propagation law of ultrasonic waves to check the defects in the workpiece. 3.2 Operating sensitivity of defects detector The ability of ultrasonic flaw detector to detect the size of defects under certain conditions. 3.3 Longitudinal wave
Waves in which the vibration direction of the medium particles is consistent with the propagation direction of the wave. 3.4 Normal probes
Probes used for longitudinal wave flaw detection.
3.5 Horizontal linearity
The degree to which the scanning voltage of the electron beam is proportional to the time. Main sound beam
The main lobe of the ultrasonic beam formed by the strong concentration of the directional characteristics of the sound source in a certain direction. Piezoelectric plate
The electroacoustic conversion element in the probe.
3.8 Mode of sweep
The way the probe moves during flaw detection.
3.9 Range of pulse
The distance that the sound wave propagates in the workpiece.
3.10 Coupling media of pulse The medium applied to transmit the ultrasonic wave emitted from the probe to the workpiece and avoid the formation of a gap between the probe and the flaw detection surface of the workpiece (such as water, motor oil, etc.).
3.11 wave of base
The display signal of the reflected wave caused by the bottom surface of the workpiece. 3.12 wave of defect
The display signal of the reflected wave caused by the defect. 4 General provisions
JB/T9674-1999
4.1 Personnel engaged in non-destructive testing must have a technical qualification certificate for non-destructive testing personnel issued by the relevant national competent authorities. 4.2 Provisions for ultrasonic flaw detectors
Ultrasonic flaw detectors should meet the following requirements: a) The operating frequency of the instrument should include 1~5MHz: b) The nominal detection depth of the instrument should not be less than the height of the test object; c) It has an attenuator with a total attenuation of not less than 50dB and an attenuation adjustment accuracy of less than ±1dB; d) When the transmission power of the flaw detector is large and the power supply voltage changes within the range of ±10% of the nominal voltage, there should be no obvious changes in the horizontal linearity.
4.3 Provisions for probes
The probe should meet the following requirements:
a) Use a single straight probe and select the probe frequency within the range of 1 to 5MHz as required, with 1.25MHz or 2.5MHz recommended. The diameter of the probe wafer can be selected as required:
b) The vertical deflection angle of the ultrasonic main sound beam emitted by the probe should not exceed 2°. 4.4 Provisions for test products
The parallelism of the two end faces of the porcelain piece and the straightness of the main axis should comply with the provisions of GB772. The detection surface should be smooth and its roughness should not exceed 10μm.
4.5 Provisions for coupling agent
Good acoustic coupling agent, such as water, engine oil, etc., should be used, and the coupling agent must be kept clean. 5 Test requirements
5.1 The test should not be carried out in places with high-frequency electromagnetic fields, strong vibrations and corrosive gases. 5.2 Use artificial standard defects to determine the working sensitivity of the flaw detector. Before starting the flaw detection, it is necessary to recalibrate the working sensitivity of the flaw detector with an artificial standard defect sample.
5.3 In order to ensure that no defects are missed, the scanning speed should not be too fast. This standard recommends two scanning methods, continuous for porcelain sleeves and intermittent for solid porcelain parts. The probe should generally be no less than 5mm away from the inner and outer arcs of the porcelain part. 5.4 For porcelain parts with a height greater than 800mm, detection should be carried out on both end faces respectively. 6 Artificial standard defect samples
6.1 Requirements for artificial standard defect samples
There shall be no natural defects that affect detection, the chaotic reflection signal on the fluorescent screen is weak, and the waveform is clear and discernible. 6.2 Preparation of artificial standard defect samples
The preparation of artificial standard defect samples is to saw a cut of a specified depth at the lower end away from the detection surface. The vertical distance between the cut and the lower end is not less than 30mm. The recommended saw cut depth is shown in Table 1.7 Working sensitivity of flaw detector
The working sensitivity of flaw detector is calibrated by artificial standard defect samples. 2
JB/T9674-1999
Place the probe on the end face of the test piece away from the artificial defect, adjust the instrument sensitivity control knob so that the height of the first artificial defect wave is 50% of the full amplitude of the fluorescent screen. The sensitivity at this time is defined as the working sensitivity of the flaw detector. When the sound path of the test piece is different from that of the artificial standard defect sample, the working sensitivity of the flaw detector that has been calibrated on the standard sample needs to be further increased or attenuated by AS (dB) to calibrate the working sensitivity of the flaw detector. AS is recommended to be calculated as follows: AS=40 lg
Where: △S is the gain or attenuation value required to compensate for the change of defect wave caused by different sound paths, dB; SA is the maximum sound path of the test piece, mm;
Xr is the maximum sound path of the artificial defect sample, mm. When the porcelain of the test piece is different from that of the artificial standard defect sample, the working sensitivity of the flaw detector calibrated on the standard sample needs to be increased or attenuated by the transmission difference △T (dB) to calibrate the working sensitivity of the flaw detector. △T can be obtained by the following actual measurement method: Place the probe on the standard sample, adjust the instrument to display at least two bottom waves, and make the height of the first bottom wave 80% of the full amplitude of the fluorescent screen, then mark the bottom wave values ​​displayed on the fluorescent screen and connect them into a curve. Finally, place the probe on the test piece, and the gain or attenuation decibel value required to make the height of the bottom wave of the test piece and the curve coincide with those of the standard sample is △T. Table 1 Arch height of saw cut of porcelain parts
Total height of test specimen
8 Basis for rejection
Solid porcelain parts
8.1 When any of the following phenomena occurs under the working sensitivity of the calibrated flaw detector, the parts shall be rejected. a) No bottom wave;
b) The bottom wave is obviously delayed;
c) When there is a bottom wave and a defect wave; the defect wave affects the height of the bottom wave, and when the probe is used to detect flaws at both end faces, the sum of the sound paths of the defect from the upper and lower end faces is equal to or substantially equal to the total sound path of the porcelain parts; d) When there is no defect wave, but the amplitude of the bottom wave is lower than 50% of the full amplitude of the fluorescent screen: solid porcelain parts shall be rejected; for porcelain sleeves, other methods may be used for verification according to the specific situation before making a judgment. 8.2 If the user has special requirements, the boundary can be ensured according to the agreement between the supply and demand parties. 9 Detection records Www.bzxZ.net
Detection records generally include the following:
a) Detection personnel and date;
b) Product specifications, models and numbers;
c) Instrument model and instrument knobs (coarse adjustment, gain, output, suppression, compensation, attenuation) readings; d) Probe frequency, type and size;
e) Detection method and coupling agent;
f) Artificial standard defect specimen;
g) Waveform,
h) Detection surface roughness;
i) Conclusion.
People's Republic of China
Mechanical Industry Standard
Ultrasonic detection of internal defects of ceramic parts
JB/T96741999
Published by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Format 880×1230
Print Sheet X/X
Edition X, XX, 19XX
Number of words xXX,XXX
Printing X, XX, 19XX
Printing 1-XXX
Price XXX.XX Yuan
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