JB/T 5441-1991 Ultrasonic flaw detection of compressor cast steel parts
Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB5441-91
Ultrasonic flaw detection of compressor cast steel parts
Published on July 22, 1991
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Implemented on July 1, 1992
Mechanical Industry Standard of the People's Republic of China
Ultrasonic flaw detection of compressor cast steel parts
1 Subject content and scope of application
JB5441-91
This standard specifies the flaw detection method and defect grade classification using A-type pulse reflection ultrasonic flaw detector. This standard applies to ultrasonic flaw detection of compressor cast steel parts (hereinafter referred to as workpieces) and other similar parts. This standard does not apply to ultrasonic flaw detection of coarse-grained steel castings such as austenitic stainless steel. 2 Reference standards
GB7233
ZBY230
Ultrasonic flaw detection method and quality rating method for steel castingsGeneral technical conditions for type A pulse reflection ultrasonic flaw detectorZBJ04001Test method for working performance of type A pulse reflection ultrasonic flaw detection systemJB3111
3 Terminology
3.1 Planar defects
Terminology of non-destructive testing
When a defect is detected by the method specified in this standard, if only its two-dimensional dimensions can be measured, it is called a planar defect. 3.2 Non-planar defects
When a defect is detected by the method specified in this standard, if its three-dimensional dimensions can be measured, it is called a non-planar defect. 3.3Other terms in this standard conform to the provisions of JB3111 and GB7233. 4 Flaw detectors
Flaw detectors for cast steel parts of compressors shall be conducted by persons who have certain basic knowledge and experience in flaw detection of castings and have obtained qualification certificates recognized by relevant departments after examination.
5 Flaw detectors
5.1 Flaw detectors
5.1.1 A type pulse reflection ultrasonic flaw detector shall be used, and its frequency range shall be between 1 and 5 MHz. 5.1.2 The instrument shall display linearly within at least 75% of the full scale, and the vertical linear error shall not be greater than 5%. 5.1.3 The instrument's horizontal linearity, resolution, and attenuator accuracy shall all comply with the relevant provisions of ZBY230. 5.2 Probes
5.2.1 The chip diameter of the longitudinal wave straight probe shall be between 10 and 30 mm, the operating frequency shall be 1 to 5 MHz, and the frequency error shall be ±10%. 5.2.2 The chip area of the shear wave oblique probe should be between 100 and 400 mm, and the K value is generally 1 to 3. 5.2.3 The acoustic insulation between the chips of the longitudinal wave dual crystal straight probe must be good. 5.3 Performance of the instrument system
The sensitivity margin and resolution of the instrument system should be tested in accordance with the relevant provisions of ZBJ04001. 5.3.1 At the operating frequency, the sensitivity margin of the longitudinal wave straight probe shall not be less than 30dF, and the sensitivity margin of the shear wave oblique probe shall be in accordance with the provisions of Appendix A (Approved by the Ministry of Machinery and Electronics Industry on July 22, 1991 and implemented on July 1, 1992) A1.2.
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5.3.2 At the operating frequency, the resolution of the longitudinal wave straight probe shall not be less than 20dB, and the resolution of the shear wave oblique probe shall not be less than 15dB. 5.4 Test Blocks
The standard test blocks are made of cast carbon steel or low alloy steel. Their sound transmittance shall be the same or similar to that of the cast steel parts to be inspected. Defects greater than or equal to the equivalent of a flat bottom hole of 2 mm are not allowed. Forged steel test blocks may also be used as a substitute through sound transmission compensation. 5.4.1 Standard test blocks for longitudinal wave straight probes 5.4.1.1 When the workpiece detection distance is greater than or equal to 1.6 times the near field area, a longitudinal wave straight probe shall be used. 5.4.1.2 The shape and size of the standard test blocks for longitudinal wave straight probe flaw detection shall be in accordance with Figure 1 and Table 1. 84
Standard test blocks for longitudinal wave twin crystal straight probes 5.4.2
When the workpiece detection distance is less than 1.6 times the near field area, a longitudinal wave twin crystal straight probe shall be used. The shape and size of the standard test block used for longitudinal wave dual crystal straight probe flaw detection shall be in accordance with Figure 2 and Table 2. 5.4.2.2
Detection distance L
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The shape and size of the standard test block used for transverse wave oblique probe flaw detection shall be in accordance with the provisions of A1.3 in Appendix A and Figure A1. mm
When the flaw detection surface is a curved surface, a comparison test block with the same or close radius of curvature as the workpiece (0.7 to 1.1 times) shall be used to determine the sound energy loss caused by the different curvatures. Its shape and size shall be in accordance with Figure 3 and Table 1. R is 0.7 to 1.1 times the radius of curvature of the workpiece
5.5 Coupling agent
Coupling agents with good sound transmission performance and no damage to the workpiece, such as engine oil, glycerin, grease, etc., can be used. 6 Inspection timing and preparation
6.1 In principle, inspection should be carried out after the final heat treatment. If the shape of the casting after heat treatment is not suitable for ultrasonic inspection, it can also be arranged before heat treatment, but after heat treatment, it should still be inspected as completely as possible. 6.2 Castings should be inspected ultrasonically only after the appearance inspection is qualified, and all materials that affect ultrasonic inspection should be removed. 6.3 The surface roughness value of the inspection surface should be R3.2um. 7 Inspection method
The main inspection methods for ultrasonic inspection of workpieces are longitudinal wave straight probe and longitudinal wave dual crystal straight probe. If it is impossible to use longitudinal wave inspection alone for effective inspection due to the limitation of workpiece shape and defect direction, the transverse wave inspection method specified in Appendix A can be used after consultation and agreement between the supply and demand parties. 7.1 Detection direction
7.1.1 In principle, it should be carried out from two mutually perpendicular directions on the detection surface, and the entire volume of the workpiece should be scanned as much as possible. 7.1.2 The detection direction of the main workpiece is shown in Figure 4. High-pressure cylinder body and high-pressure cylinder head
7.2 Scanning
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d Connecting rod
7.2.1 The entire detection surface of the workpiece should be scanned comprehensively and continuously, and the overlapping part of two adjacent scans is about 15% of the diameter of the probe wafer.
7.2.2 During scanning, the moving speed of the probe shall not exceed 150mm/s. JD544191
7.2.3 Areas that cannot be scanned due to the geometric shape of the workpiece should be noted in the flaw detection report. 7.3 Determination of sound transmission
Couple the longitudinal wave straight probe with the defect-free part of the workpiece that is parallel to the detection surface and the bottom surface, adjust the instrument so that the amplitude of the first bottom echo reaches 50% of the full scale, record the attenuator reading at this time, and then adjust the attenuator so that the amplitude of the second bottom echo reaches 50% of the full scale. The difference between the two attenuator readings is the sound transmission of the measurement point. The measurement points shall not be less than three, and the average value shall be used to represent the acoustic permeability of the area.
7.4 Determination of flaw detection sensitivity
7.4.1 Adjustment of the flaw detection sensitivity of the longitudinal wave straight probe First, compare the workpiece with a standard test block whose detection distance is equal to or closest to the thickness of the workpiece, and calculate the acoustic permeability compensation value and the surface roughness compensation value. Then test on the test block so that the echo amplitude of the Φ4mm flat-bottom hole reaches 10% to 20% of the full scale. Without changing the parameters of the instrument, test a series of test blocks with a smaller detection distance one by one, measure the highest point of the flat-bottom hole echo, draw it on the fluorescent screen, connect these points, and you can establish a distance-amplitude curve. You can also use the A, V, G calculation method or the A, V, G curve plate to determine the distance-amplitude curve. 7.4.2 Adjustment of the flaw detection sensitivity of the longitudinal wave dual crystal probe Test a group of Φ4mm flat-bottom holes with different detection distances, adjust the attenuator, and make the highest echo amplitude reach 80% of the full scale without changing the parameters of the instrument. Test the flat-bottom holes with different detection distances one by one, draw the highest point of their echo amplitude on the fluorescent screen, and connect these points to establish a distance-amplitude curve. 7.4.3 Compensation
7.4.3.1 Surface roughness compensation: During flaw detection and defect quantification, the energy consumption caused by surface roughness should be compensated. 7.4.3.2 Acoustic permeability compensation: During detection and defect quantification, the acoustic permeability compensation should be made for the errors in flaw detection sensitivity and defect equivalent caused by acoustic permeability.
7.4.3.3 Curved surface compensation: For workpieces with curved detection surfaces, a comparison test block with a curvature radius that is the same or close to that of the workpiece (0.71.1 times) should be used for correction, otherwise appropriate curved surface compensation should be made. 7.4.4 The detection sensitivity shall not be lower than the equivalent of a 4mm flat-bottom hole at the maximum detection distance. 7.5 Review of flaw detection sensitivity
During flaw detection, the flaw detection sensitivity should be checked, and if the flaw detection sensitivity is found to have changed, it should be readjusted. When the gain level decreases by more than 2dB, the workpieces inspected since the last calibration shall be re-tested; when the gain level increases by more than 2dB, all recorded defects shall be re-equalized.
8. Defect Detection
8.1 Recorded Defects
8.1.7 Defects with reflected echo amplitude equal to or higher than the distance-amplitude curve. 8.1.2 Defects that cause the first bottom echo of the workpiece to disappear under the detection sensitivity. 8.1.3 Planar defects appear and are judged as hazardous defects by the flaw detector. 8.2 Determination of defect size
8.2.1 When the defect echo amplitude is equal to or higher than the distance-amplitude curve, the range of the defect is drawn on the detection surface using the 6dB method. Its size in the thickness direction of the workpiece can be determined by the upper and lower boundaries of the defect determined by detection in different directions. 8.2.2 For any defect that causes the bottom echo to disappear due to the existence of a defect, its edge should be measured from the center of the probe when the bottom reflection wave just disappears on the detection surface to the center of the probe when the bottom reflection wave appears. The depth of the defect is determined by the peak position on the leftmost side of a group of continuous defect echoes. 8.2.3 When the distance between two defects is less than the diameter of the larger defect, the two defects can be converted into one defect, and the defect area is measured according to actual measurement. 8.2.4 The area of a single defect is calculated as the product of the maximum size of the defect and its maximum size in the vertical direction. 8.2.5 For defects in question, other effective methods may also be used for verification. 9 Defect grade classification
9.1 Cracks and shrinkage cavities are not allowed in the inspection area. 5
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The size of the defect in the thickness direction of the workpiece shall not be greater than 1/8 of the wall thickness. The cross-sectional area where the defect is located refers to the minimum cross-sectional area of the defect detected; for hollow shaft workpieces, the cross-sectional area should be calculated as a solid shaft. The single defect grade classification of the workpiece is specified in Table 3; the area defect grade classification is specified in Table 4. Table 3
Equivalent diameter of defect
Flaw detection report
The flaw detection report should include the following contents:
Defects exceeding the amplitude reference line
The defect area is less than or equal to 5% of the cross-sectional area where the defect is located4
Defects of disappearing bottom wave
The defect area is less than or equal to 10% of the cross-sectional area where the defect is locatedThe defect area is less than or equal to 15% of the cross-sectional area where the defect is locatedThe defect area is less than or equal to 20% of the cross-sectional area where the defect is locatedThe defect area is less than or equal to 25% of the cross-sectional area where the defect is locatedThe defect area is greater than 25% of the cross-sectional area where the defect is locatedUnit who entrusts the flaw detection, the flaw detection report number, and the date of issuance; the name, number, material grade, heat treatment status, surface roughness of the flaw detection surface, sound transmittance, and workpiece size sketch of the steel casting; the model of the ultrasonic detector, the model of the probe, the flaw detection frequency, the coupling agent, and the flaw detection sensitivity; on the sketch, mark the inspection area. If there are areas that cannot be inspected due to geometric limitations, they must also be indicated on the sketch; defect type, size and location;
defect grade and flaw detection conclusion;
signatures of the flaw detector and auditor. Qualification number, grade, name and flaw detection date of the flaw detector. A1
Testing equipment
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Appendix A
Shear wave test
(Supplement)
A1.1 The performance of the instrument and probe shall comply with the requirements of Articles 5.1, 5.2 and 5.3. A1.2 The combined sensitivity margin of the instrument and probe shall not be less than 10dB when the maximum detection sound range of the workpiece is reached. The shape and size of the calibration test block shall be in accordance with Figure A1 and Table A1A1.3
Nominal thickness of material
>25~50
>50~100
>100~150
>150~200
Preparation of distance-amplitude curve
Thickness of calibration test block T
Using the basic calibration test block shown in Figure A1, an oblique probe is used to detect the transverse holes of the test block with depth positions of T/4, T/2, and 3T/4, and each amplitude point is marked on the fluorescent screen. Connecting these points will obtain the distance-amplitude curve. A3 Scanning
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Shear wave oblique probe flaw detection should be scanned at least in two directions perpendicular to each other on the flaw detection surface. While scanning, the probe should be continuously deflected, and the deflection angle should not be less than 15°.
Defect record
Record defects where the echo amplitude exceeds the distance-amplitude curve. A4.1
A4.2Hazardous defects that the flaw detector considers necessary to record. A5Acceptance criteria
Acceptance criteria shall be agreed upon by both the supplier and the buyer.
A6Flaw detection report
Flaw detection reports shall comply with the provisions of Chapter 10 of this standard. Additional notes:
This standard was proposed by the National Technical Committee for Compressor Standardization. This standard was drafted by the Hefei General Machinery Research Institute of the Ministry of Machinery and Electronics Industry. The main drafter of this standard was Yuan Gerong.
People's Republic of China
Mechanical Industry Standard
Ultrasonic Flaw Detection of Cast Steel Parts of Compressor
JB544191www.bzxz.net
Published and distributed by the Mechanical Standardization Research Institute of the Ministry of Machinery and Electronics Industry (PO Box 8144, Beijing
Copyright reserved
Postal Code 100081)
No Reproduction
Printed in Qinghe County Printing Factory, Hebei Province
Format 880×1230
First Edition in October 1991
Sheet 3/4
Number of Words 16000
First Printing in October 1991
Number of Prints 00.001-1000 Price 1.20 Yuan
No. 02553
Nominal material thickness
>25~50
>50~100
>100~150
>150~200
Preparation of distance-amplitude curve
Thickness of calibration test block T
Use the basic calibration test block shown in Figure A1, use an oblique probe, and probe the horizontal holes of the test block with depth positions of T/4, T/2, and 3T/4, and mark each amplitude point on the fluorescent screen, and connect these points to get the distance-amplitude curve. A3 Scanning
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Shear wave oblique probe flaw detection should be scanned at least in two directions perpendicular to each other on the flaw detection surface. While scanning, the probe should be continuously deflected, and the deflection angle should not be less than 15°.
Defect recording
Record defects whose echo amplitude exceeds the distance-amplitude curve. A4.1
A4.2 Hazardous defects that the flaw detector considers necessary to record. A5 Acceptance criteria
Acceptance criteria shall be agreed upon by both the supplier and the buyer.
A6 Flaw detection report
Flaw detection reports shall comply with the provisions of Chapter 10 of this standard. Additional notes:
This standard was proposed by the National Technical Committee for Compressor Standardization. This standard was drafted by the Hefei General Machinery Research Institute of the Ministry of Machinery and Electronics Industry. The main drafter of this standard was Yuan Gerong.
People's Republic of China
Mechanical Industry Standard
Ultrasonic Flaw Detection of Cast Steel Parts of Compressor
JB544191
Published and distributed by the Mechanical Standardization Research Institute of the Ministry of Machinery and Electronics Industry (PO Box 8144, Beijing
Copyright reserved
Postal Code 100081)
No Reproduction
Printed by Qinghe County Printing Factory, Hebei Province
Format 880×1230
First Edition in October 1991
Sheet 3/4
Word Count 16000
First Printing in October 1991
Print Quantity 00.001-1000 Price 1.20 Yuan
No. 02553
Nominal material thickness
>25~50
>50~100
>100~150
>150~200
Preparation of distance-amplitude curve
Thickness of calibration test block T
Use the basic calibration test block shown in Figure A1, use an oblique probe, and probe the horizontal holes of the test block with depth positions of T/4, T/2, and 3T/4, and mark each amplitude point on the fluorescent screen, and connect these points to get the distance-amplitude curve. A3 Scanning
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Shear wave oblique probe flaw detection should be scanned at least in two directions perpendicular to each other on the flaw detection surface. While scanning, the probe should be continuously deflected, and the deflection angle should not be less than 15°.
Defect recording
Record defects whose echo amplitude exceeds the distance-amplitude curve. A4.1
A4.2 Hazardous defects that the flaw detector considers necessary to record. A5 Acceptance criteria
Acceptance criteria shall be agreed upon by both the supplier and the buyer.
A6 Flaw detection report
Flaw detection reports shall comply with the provisions of Chapter 10 of this standard. Additional notes:
This standard was proposed by the National Technical Committee for Compressor Standardization. This standard was drafted by the Hefei General Machinery Research Institute of the Ministry of Machinery and Electronics Industry. The main drafter of this standard was Yuan Gerong.
People's Republic of China
Mechanical Industry Standard
Ultrasonic Flaw Detection of Cast Steel Parts of Compressor
JB544191
Published and distributed by the Mechanical Standardization Research Institute of the Ministry of Machinery and Electronics Industry (PO Box 8144, Beijing
Copyright reserved
Postal Code 100081)
No Reproduction
Printed in Qinghe County Printing Factory, Hebei Province
Format 880×1230
First Edition in October 1991
Sheet 3/4
Number of Words 16000
First Printing in October 1991
Number of Prints 00.001-1000 Price 1.20 Yuan
No. 0255
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