Some standard content:
Machinery Industry Standard of the People's Republic of China
Ultrasonic inspection method of valve forgings
1 Subject content and scope of application
JB/T 6903 --- 93
This standard stipulates The flaw detection method and defect grade classification using the A-type pulse reflection ultrasonic flaw detector are explained. This standard is applicable to ultrasonic flaw detection of valve steel forgings. This standard is not applicable to ultrasonic flaw detection of austenitic steel forgings. 2 Reference standards
GB/T12604 Non-destructive testing terminology
ZBJ04001A type pulse reflection ultrasonic flaw detection system working performance test method ZBY230A type pulse reflection ultrasonic flaw detector general technical conditions 3 terms
3.1 Dense area defects
There are 3 or more defect reflection signals at the same time within the 30mm sound path range of the fluorescent screen scanning line, or on the 30mm×30mm detection surface (within the same depth range) If there are 3 or more defect reflection signals, the reflection amplitude should be greater than the reflection amplitude of a specific equivalent defect.
3.2 The amount of bottom wave reduction caused by defects BG/BF (dB) The ratio of the amplitude of the first bottom wave height BG in the defect-free intact area and the first bottom wave height BF in the defective area , represented by dB value.
3.3 Other terms should comply with the provisions of GB/T12604. 4. Flaw detection personnel
The flaw detection of valve forgings should be carried out by those who have certain basic knowledge and experience in forging flaw detection, and have obtained qualification certificates recognized by relevant departments after assessment.
5 Flaw Detection Equipment
5.1 Flaw Detector
5.1.1 adopts A-type pulse reflection ultrasonic flaw detector, and its frequency should be 1~5MHz. 5.1.2 The instrument should display linearly within at least 75% of the full scale, and the vertical linearity error shall not be greater than 5%. 5.1.3 The instrument’s horizontal linearity, resolution, attenuator accuracy and other indicators should comply with the relevant regulations of ZBY230. 5.2 Probe
5.2.1 The element diameter of the longitudinal wave straight probe should be between 10~30mm, the operating frequency should be 1~~5MHz, and the error should not exceed ±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 elements of the longitudinal wave double crystal straight probe must be good. 5.3 Performance of the instrument system
The Ministry of Machinery Industry of the People's Republic of China approved 664 on 1993-07-13
1994-07-01 implementation
JB/T6903-93
Instrument The sensitivity margin and resolution of the system should be tested according to the relevant regulations of ZBJ040Q1. 5.3.1 Within the operating frequency range, the sensitivity margin of longitudinal wave straight probes shall not be less than 30dB, and the sensitivity margin of shear wave oblique probes shall be in accordance with Article A1.2 in Appendix A (Supplement). 5.3.2 Within the operating frequency range, the resolution of longitudinal wave straight probes shall not be less than 20dB, and the resolution of shear wave oblique probes shall not be less than 15dB. || tt | Defects.
5.4.1 Standard test blocks used for longitudinal wave straight probes 5.4.1.1 When the detection distance of small pieces is greater than or equal to 45mm, longitudinal wave straight probes should be used 5.4.1.2 Standard test blocks for longitudinal wave straight probe flaw detection should use CS1 and CS2 Test block. If it is difficult to purchase, you can also process it yourself. The shape and size are as shown in Figure 1 and Table 1.
D
L
D (diameter)
56
50
5.4.2 Standard test used for longitudinal wave double element straight probe piece. Figure 1 | | tt | | Table 1 | | tt | | 100 | | tt | | 60 | | tt | 2
D
150
80
b
All
A
10. 05A
m | 250
Female
25×8
Middle
112
H3
4
0i5 6||tt| |Figure 2
665
Sequence
2
3
4
6
8
9
No.
42
JB/T 6903 · 93
Table 2
$3
Detection
Test| |tt||distance
5
10
15
20
25
30
35||tt ||40
45
off
*4
96
m
5.4.3 Standard test used for shear wave oblique probe flaw detection The shape and size of the block are as specified in Appendix A (Supplement) A1.3 and Figure A1. 5.4.4 When the flaw detection surface is a curved surface, a comparison test block roughly equivalent to the curvature radius R of the workpiece (0.9~1.5 times) should be used for measurement. Its shape and size are as shown in Figure 3,
5.5 Coupling Agent| |tt||Coupling agents such as engine oil, glycerin, and grease that have good sound transmission properties and do not damage the workpiece should be used. All
Figure 3
6 Flaw detection timing and preparation work
3.2,
6.1 Flaw detection should generally be performed after the final heat treatment. If the shape of the workpiece after heat treatment is not suitable for ultrasonic flaw detection, the flaw detection can also be arranged before heat treatment, but it should still be inspected as completely as possible after heat treatment. 6.2 Ultrasonic flaw detection can only be carried out after the workpiece has passed the visual inspection. All oil stains and other attachments that affect ultrasonic flaw detection should be removed. 6.3 The surface roughness Ra of the flaw detection surface is 6.3μm. Flaw detection method
The ultrasonic flaw detection method of the workpiece is mainly longitudinal wave straight probe and longitudinal wave double element straight probe. If longitudinal wave flaw detection alone cannot be used for effective detection due to restrictions on the shape of the workpiece and the direction of the defect, transverse wave flaw detection specified in Appendix A (Supplement) can be used with the agreement of both parties. 7.1 Detection direction
7.1.1 Generally, the detection is carried out in 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 An example of the detection direction of valve forgings is shown in Figure 4. 666
Valve cover
93
IB/T 6903—
Closed body
C
Figure 4
Valve Block
h
667
7.2 Scanning
JB/T 6903- 93
7.2.1 The entire detection surface of the workpiece should be comprehensively and continuously scanned check. The overlap between two adjacent scans is approximately 15% of the diameter of the probe element.
7.2.2 During scanning, the moving speed of the probe shall not exceed 150mm/s. 7.2.3 Areas that cannot be scanned due to the complex geometry of the workpiece should be noted in the flaw detection report 7.3 Determination of the attenuation coefficient of the workpiece material
7.3.1 Select three detection surfaces in the defect-free and intact area of ??the workpiece Parallel to the bottom surface and a representative part, adjust the instrument so that the echo amplitude (B,) of the second bottom surface is 50% of the full scale, and record the reading of the attenuator at this time; then adjust the attenuator so that the echo amplitude (B,) of the second bottom surface The echo amplitude (B,) is 50% of the full scale. The difference between the two attenuator readings is the dB difference of (B, B2>. 7.3.2 The calculation formula of the attenuation coefficient is:
(3,
In the formula: α-——attenuation coefficient, dB/m;
B:B..-the difference between the readings of the two attenuators.dB; T—the detection sound path of the workpiece, m | |7.4.1 Determination of flaw detection sensitivity of longitudinal wave straight probe When the thickness of the detected part is greater than 3 times the near field area of ??the probe, bottom wave (adopting A, V, G calculation method) is generally used to determine the flaw detection sensitivity due to limitations of the geometry. , if the bottom wave cannot be obtained or the detection thickness is greater than 45mm and less than 3 times the near field area, the test block method can be directly used to determine the flaw detection sensitivity
7.4.2. Determination of flaw detection sensitivity of longitudinal wave double crystal straight probe. Select test blocks with flat-bottomed holes of different diameters as needed, and test a set of flat-bottomed holes (at least 6) with different detection distances. Adjust the attenuator so that the highest echo amplitude reaches 80% of full scale. Without changing the parameters of the instrument, measure the highest points of echoes from other flat-bottomed holes and calibrate them on the fluorescent screen; connecting these points is the distance-amplitude curve of the longitudinal-wave dual-element straight probe corresponding to different flat-bottomed holes. 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 Material attenuation compensation
During flaw detection and defect quantification, attenuation compensation should be made for changes in flaw detection sensitivity and defect equivalent caused by material attenuation. 7.4.3.3 Curved surface compensation
For work where the detection surface is a curved surface, a reference test block with the same curvature as or close to the workpiece (0.9 to 1.5 times) can be used. Otherwise, the sound energy loss caused by different curvatures should be compensated.
7.4.4 The flaw detection sensitivity is generally not lower than the equivalent of a Φ2mm flat-bottomed hole at the maximum detection distance of the workpiece. 7.5 Review of flaw detection sensitivity bzxZ.net
The flaw detection sensitivity should be checked during flaw detection, and it should be readjusted if it is found that the flaw detection sensitivity has changed. When the gain level decreases by more than 2d3, the workpieces inspected since the last calibration should be re-detected; when the gain level increases by more than 2dB, all recorded defects should be re-quantified.
8 Defect records
8.1 Determination of defect equivalent
8.1.1 Use A, V, G calculation method to determine equivalent. For those located in the near field area where the above method cannot be used to determine the defect equivalent, a dual-element straight probe can be used, and test blocks with flat-bottomed holes of different diameters can be used to determine the defect equivalent through a comparison method. 668
JB/T6903--93
8.1.2 The boundaries of defect-intensive areas and single large defects can be determined using the half-wave height method. 8.1.3 If the material attenuation coefficient exceeds 4dB/m when calculating the defect equivalent, it should be corrected. 8.2 Defect record
8.2.1 Record the location and amplitude of a single defect with an equivalent flat-bottomed hole diameter exceeding Φ4mm, 8.2.2 Record the defect-intensive area with an equivalent flat-bottomed hole diameter exceeding 3mm and the location and distribution of its largest defect. Defect density The area of ??the area is a square of 30 mm × 30 mm as the minimum measurement unit. 8.2.3 Record the area and value of the bottom echo reduction caused by defects. 8.2.4 Record the material attenuation coefficient.
8.2.5 However, defects that do not fall into the above situations, but which the inspection personnel can determine whether they are hazardous, should also be recorded. Defect grade classification
9
The grade classification of a single defect is specified in Table 3. 9.1 | | tt | | Table 3 | The classification is specified in Table 4. etc.
Level
Defect intensive area
Percentage of total flaw detection area
0
6
Table 4
>0~5
9.3 The level classification of back wave reduction caused by defects shall be as specified in Table 5. Table 5
etc
level
back wave reduction amount
BG/BF
8
2
>8 ~14
8
>5~10
3
>1420
9.4 The grades in Table 3, Table 4 and Table 5 are used in evaluating the quality of workpieces should be used separately as independent levels. 9.5 Defects judged to be dangerous by inspection personnel should be rated as level 4. 10 Acceptance level
8
>10
·20
mm
dB
Defect level 4 unqualified, user and design Personnel can also select a higher level as the qualification level for valve forgings as needed. Valve forgings after welding repairs should be inspected with emphasis on the welding repair location and heat-affected zone. The inspection methods and defect grade classification are still in accordance with the provisions of this standard.
Flaw detection report
11
The flaw detection report should include the following contents:
11.1 The unit entrusted with the flaw detection, the flaw detection report number, and the issuance period. The name, serial number, material grade, heat treatment status, and surface roughness of the flaw detection surface of the forged steel parts. 11.2
11.3 Model of flaw detector, probe model, flaw detection frequency, coupling agent, flaw detection sensitivity and scanning method. 11.4 Mark the detection area on the sketch. If there are parts that cannot be detected due to geometric restrictions, they must also be marked on the sketch. 11.5 Type, size and location of defects. 11.6 Defect grade and flaw detection conclusion.
Signatures of the flaw detector and auditor, qualification certificate number, grade and date of the flaw detector. 11.7
669
A1 testing equipment
93
JB/T6903
Appendix A
Transverse wave inspection
(Supplementary Parts)
The performance of A1.1 instruments and probes shall comply with the provisions of Articles 5.1, 5.2 and 5.3. A1.2 The combined sensitivity margin of the instrument and probe shall not exceed the maximum detection sound path of the workpiece being detected. Less than 10cB. A1.3 The shape and size of the calibration test block are shown in Figure A1 and Table A1. 40
Nominal thickness of material
25
>25～50
>50～100
>100~～150
>150 ~200
A2
Production of distance-amplitude curve
100
Figure Al
Table A1
Thickness of test block!
25
50
100
150
200
40
ApertureΦ
2.5| |tt||3.0
5. 0)
6.0
8.0
mn
Use the basic calibration test block shown in Figure A1, using the oblique The probe probes the transverse holes at the depth positions of T/4, T/2, and 3T/4 in the test block. Find the positions of the maximum reflected wave points and mark them on the fluorescent screen. Connect these points to get the distance-amplitude curve. , A3 scanning
The oblique probe must scan at least two directions perpendicular to each other on the flaw detection surface. The probe should be continuously deflected during scanning, and the deflection angle must not be less than 15°.
A4
Defect record
JB/T6903--93
Record defects whose echo amplitude exceeds the distance-amplitude curve and determine their geometric size and position A4. 1
A4.2
Hazardous defects that the inspection personnel deem necessary to record. A5 Acceptance Standards
The acceptance standards should be agreed upon by both parties.
Flaw detection report
A6
The flaw detection report shall be in accordance with the provisions of Chapter 11 of this standard. Additional notes:
This standard is proposed by the National Valve Standardization Technical Committee. This standard is under the jurisdiction of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by Hefei General Machinery Research Institute and Kaifeng High Pressure Valve Factory. The main drafters of this standard are Yuan Rong and Wu Yongguang. 671
5 Review of flaw detection sensitivity
The flaw detection sensitivity should be checked during flaw detection, and it should be readjusted if it is found that the flaw detection sensitivity has changed. When the gain level decreases by more than 2d3, the workpieces inspected since the last calibration should be re-detected; when the gain level increases by more than 2dB, all recorded defects should be re-quantified.
8 Defect records
8.1 Determination of defect equivalent
8.1.1 Use A, V, G calculation method to determine equivalent. If the defect equivalent cannot be determined by the above method in the near field area, a dual-crystal straight probe can be used, and test blocks with flat-bottomed holes of different diameters can be used to determine the defect equivalent through a comparison method. 668
JB/T6903--93
8.1.2 The boundaries of defect-intensive areas and single large defects can be determined using the half-wave height method. 8.1.3 If the material attenuation coefficient exceeds 4dB/m when calculating the defect equivalent, it should be corrected. 8.2 Defect record
8.2.1 Record the location and amplitude of a single defect with an equivalent flat-bottomed hole diameter exceeding Φ4mm, 8.2.2 Record the defect-intensive area with an equivalent flat-bottomed hole diameter exceeding 3mm and the location and distribution of its largest defect. Defect density The area of ??the area is a square of 30 mm × 30 mm as the minimum measurement unit. 8.2.3 Record the area and value of the bottom echo reduction caused by defects. 8.2.4 Record the material attenuation coefficient.
8.2.5 However, defects that do not fall into the above situations, but which the inspection personnel can determine whether they are hazardous, should also be recorded. Defect grade classification
9
The grade classification of a single defect is specified in Table 3. 9.1
Table 3
etc
level
equivalent defect diameter
9.2
4
level of defect intensive area The classification is specified in Table 4. etc.
Level
Defect intensive area
Percentage of total flaw detection area
0
6
Table 4
>0~5
9.3 The level classification of back wave reduction caused by defects shall be as specified in Table 5. Table 5
etc
level
back wave reduction amount
BG/BF
8
2
>8 ~14
8
>5~10
3
>1420
9.4 The grades in Table 3, Table 4 and Table 5 are used in evaluating the quality of workpieces should be used separately as independent levels. 9.5 Defects judged to be dangerous by inspection personnel should be rated as level 4. 10 Acceptance level
8
>10
·20
mm
dB
Defect level 4 unqualified, user and design Personnel can also select a higher level as the qualification level for valve forgings as needed. Valve forgings after welding repairs should be inspected with emphasis on the welding repair location and heat-affected zone. The inspection methods and defect grade classification are still in accordance with the provisions of this standard.
Flaw detection report
11
The flaw detection report should include the following contents:
11.1 The unit entrusted with the flaw detection, the flaw detection report number, and the issuance period. The name, serial number, material grade, heat treatment status, and surface roughness of the flaw detection surface of the forged steel parts. 11.2
11.3 Model of flaw detector, probe model, flaw detection frequency, coupling agent, flaw detection sensitivity and scanning method. 11.4 Mark the detection area on the sketch. If there are parts that cannot be detected due to geometric restrictions, they must also be marked on the sketch. 11.5 Type, size and location of defects. 11.6 Defect grade and flaw detection conclusion.
Signatures of the flaw detector and auditor, qualification certificate number, grade and date of the flaw detector. 11.7
669
A1 testing equipment
93
JB/T6903
Appendix A
Transverse wave inspection
(Supplementary Parts)
The performance of A1.1 instruments and probes shall comply with the provisions of Articles 5.1, 5.2 and 5.3. A1.2 The combined sensitivity margin of the instrument and probe shall not exceed the maximum detection sound path of the workpiece being detected. Less than 10cB. A1.3 The shape and size of the calibration test block are shown in Figure A1 and Table A1. 40
Nominal thickness of material
25
>25～50
>50～100
>100~～150
>150 ~200
A2
Production of distance-amplitude curve
100
Figure Al
Table A1
Thickness of test block!
25
50
100
150
200
40
ApertureΦ
2.5| |tt||3.0
5. 0)
6.0
8.0
mn
Use the basic calibration test block shown in Figure A1, using the oblique The probe probes the transverse holes at the depth positions of T/4, T/2, and 3T/4 in the test block, finds out the positions of the maximum reflected wave points and marks them on the fluorescent screen. By connecting these points, the distance-amplitude curve is obtained. , A3 scanning
The oblique probe must scan at least two directions perpendicular to each other on the flaw detection surface. The probe should be continuously deflected during scanning, and the deflection angle must not be less than 15°.
A4
Defect record
JB/T6903--93
Record defects whose echo amplitude exceeds the distance-amplitude curve and determine their geometric size and position A4. 1
A4.2
Hazardous defects that the inspection personnel deem necessary to record. A5 Acceptance Standards
The acceptance standards should be agreed upon by both parties.
Flaw detection report
A6
The flaw detection report shall be in accordance with the provisions of Chapter 11 of this standard. Additional notes:
This standard is proposed by the National Valve Standardization Technical Committee. This standard is under the jurisdiction of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by Hefei General Machinery Research Institute and Kaifeng High Pressure Valve Factory. The main drafters of this standard are Yuan Rong and Wu Yongguang. 671
5 Review of flaw detection sensitivity
The flaw detection sensitivity should be checked during flaw detection, and it should be readjusted if it is found that the flaw detection sensitivity has changed. When the gain level decreases by more than 2d3, the workpieces inspected since the last calibration should be re-detected; when the gain level increases by more than 2dB, all recorded defects should be re-quantified.
8 Defect records
8.1 Determination of defect equivalent
8.1.1 Use A, V, G calculation method to determine equivalent. If the defect equivalent cannot be determined by the above method in the near field area, a dual-crystal straight probe can be used, and test blocks with flat-bottomed holes of different diameters can be used to determine the defect equivalent through the comparison method. 668
JB/T6903--93
8.1.2 The boundaries of defect-intensive areas and single large defects can be determined using the half-wave height method. 8.1.3 If the material attenuation coefficient exceeds 4dB/m when calculating the defect equivalent, it should be corrected. 8.2 Defect record
8.2.1 Record the location and amplitude of a single defect with an equivalent flat-bottomed hole diameter exceeding Φ4mm, 8.2.2 Record the defect-intensive area with an equivalent flat-bottomed hole diameter exceeding 3mm and the location and distribution of its largest defect. Defect density The area of ??the area is a square of 30 mm × 30 mm as the minimum measurement unit. 8.2.3 Record the area and value of the bottom echo reduction caused by defects. 8.2.4 Record the material attenuation coefficient.
8.2.5 However, defects that do not fall into the above situations, but which the inspection personnel can determine whether they are hazardous, should also be recorded. Defect grade classification
9
The grade classification of a single defect is specified in Table 3. 9.1
Table 3
etc
level
equivalent defect diameter
9.2
4
level of defect intensive area The classification is specified in Table 4. etc.
Level
Defect intensive area
Percentage of total flaw detection area
0
6
Table 4
>0~5
9.3 The level classification of back wave reduction caused by defects shall be as specified in Table 5. Table 5
etc
level
back wave reduction amount
BG/BF
8
2
>8 ~14
8
>5~10
3
>1420
9.4 The grades in Table 3, Table 4 and Table 5 are used in evaluating the quality of workpieces should be used separately as independent levels. 9.5 Defects judged to be dangerous by inspection personnel should be rated as level 4. 10 Acceptance level
8
>10
·20
mm
dB
Defect level 4 unqualified, user and design Personnel can also select a higher level as the qualification level for valve forgings as needed. Valve forgings after welding repairs should be inspected with emphasis on the welding repair location and heat-affected zone. The inspection methods and defect grade classification are still in accordance with the provisions of this standard.
Flaw detection report
11
The flaw detection report should include the following contents:
11.1 The unit entrusted with flaw detection, flaw detection report number, and issuance period. The name, serial number, material grade, heat treatment status, and surface roughness of the flaw detection surface of the forged steel parts. 11.2
11.3 Model of flaw detector, probe model, flaw detection frequency, coupling agent, flaw detection sensitivity and scanning method. 11.4 Mark the detection area on the sketch. If there are parts that cannot be detected due to geometric restrictions, they must also be marked on the sketch. 11.5 Type, size and location of defects. 11.6 Defect grade and flaw detection conclusion.
Signatures of the flaw detector and auditor, qualification certificate number, grade and date of the flaw detector. 11.7
669
A1 testing equipment
93
JB/T6903
Appendix A
Transverse wave inspection
(Supplementary Parts)
The performance of A1.1 instruments and probes shall comply with the provisions of Articles 5.1, 5.2 and 5.3. A1.2 The combined sensitivity margin of the instrument and probe shall not exceed the maximum detection sound path of the workpiece being detected. Less than 10cB. A1.3 The shape and size of the calibration test block are shown in Figure A1 and Table A1. 40
Nominal thickness of material
25
>25～50
>50～100
>100~～150
>150 ~200
A2
Production of distance-amplitude curve
100
Figure Al
Table A1
Thickness of test block!
25
50
100
150
200
40
ApertureΦ
2.5| |tt||3.0
5. 0)
6.0
8.0
mn
Use the basic calibration test block shown in Figure A1, using the oblique The probe probes the transverse holes at the depth positions of T/4, T/2, and 3T/4 in the test block. Find the positions of the maximum reflected wave points and mark them on the fluorescent screen. Connect these points to get the distance-amplitude curve. , A3 scanning
The oblique probe must scan at least two directions perpendicular to each other on the flaw detection surface. The probe should be continuously deflected during scanning, and the deflection angle must not be less than 15°.
A4
Defect record
JB/T6903--93
Record defects whose echo amplitude exceeds the distance-amplitude curve and determine their geometric size and position A4. 1
A4.2
Hazardous defects that the inspection personnel deem necessary to record. A5 Acceptance Standards
The acceptance standards should be agreed upon by both parties.
Flaw detection report
A6
The flaw detection report shall be in accordance with the provisions of Chapter 11 of this standard. Additional notes:
This standard is proposed by the National Valve Standardization Technical Committee. This standard is under the jurisdiction of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by Hefei General Machinery Research Institute and Kaifeng High Pressure Valve Factory. The main drafters of this standard are Yuan Rong and Wu Yongguang. 671
5 Defects determined by the flaw detector to be dangerous should be rated as level 4. 10 Acceptance level
8
>10
·20
mm
dB
Flaw level 4 is unqualified. Users and designers can also select a higher level as the qualified level of valve forgings as needed. After welding, the weld repair position and heat affected zone of the valve forgings should be inspected in detail. The inspection method and defect level classification shall still be carried out in accordance with the provisions of this standard.
Flaw detection report
11
Flaw detection report should include the following contents:
11.1 The unit that commissioned the flaw detection, the flaw detection report number, and the issuance period. The name, number, material grade, heat treatment status, and surface roughness of the flaw detection surface of the forged steel. 11.2
11.3 The model of the flaw detector, the model of the probe, the flaw detection frequency, the coupling agent, the flaw detection sensitivity, and the scanning method. 11.4 Mark the inspection area on the sketch. If there are any parts that cannot be inspected due to any shape restrictions, they must also be marked on the sketch. 11.5 Type, size and location of defects. 11.6 Defect grade and flaw detection conclusion.
Signature of the flaw detector and the reviewer, the flaw detector's qualification certificate number, grade and date. 11.7
669
A1 Inspection equipment
93
JB/T6903
Appendix A
Shear wave inspection
(Supplement)
A1.1 The performance of the instrument and probe shall comply with the provisions 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 10cB at the maximum detection sound range of the workpiece to be inspected. A1.3 The shape and size of the calibration test block are shown in Figure A1 and Table A1. 40
Nominal thickness of material
25
>25 ~50
>50~100
>100~~150
>150~200
A2
Preparation of distance-amplitude curve
100
Figure Al
Table A1
Test block thickness!
25
50
100
150
200
40
Aperture Φ
2.5
3.0
5. 0)
6.0
8.0
mn
Use the basic calibration test block shown in Figure A1, use the oblique probe to detect the horizontal holes of the test block with depth positions of T/4, T/2, and 3T/4, respectively, find the positions of each maximum reflection wave bat point and mark them on the fluorescent screen, connect these points to get its distance-amplitude curve, A3 scanning
The oblique probe should be scanned in at least two directions perpendicular to each other on the flaw detection surface. During the scanning, the probe should be deflected continuously, and the deflection angle shall not be less than 15°.
A4
Defect record
JB/T6903--93
Record defects whose echo amplitude exceeds the distance-amplitude curve and determine their geometric size and positionA4.1
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.
Flaw detection report
A6
Flaw detection report shall comply with the provisions of Chapter 11 of this standard. Additional notes:
This standard was proposed by the National Technical Committee for Valve Standardization. This standard is under the jurisdiction of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Hefei General Machinery Research Institute and Kaifeng High-Pressure Valve Factory. The main drafters of this standard are Yuan Rong and Wu Yongguang. 671
5. Defects judged to be dangerous by the inspection personnel shall be rated as Level 4. 10 Acceptance level
8
>10
·20
mm
dB
Defect level 4 unqualified, user and design Personnel can also select a higher level as the qualification level for valve forgings as needed. Valve forgings after welding repairs should be inspected with emphasis on the welding repair location and heat-affected zone. The inspection methods and defect grade classification are still in accordance with the provisions of this standard.
Flaw detection report
11
The flaw detection report should include the following contents:
11.1 The unit entrusted with the flaw detection, the flaw detection report number, and the issuance period. The name, serial number, material grade, heat treatment status, and surface roughness of the flaw detection surface of the forged steel parts. 11.2
11.3 Model of flaw detector, probe model, flaw detection frequency, coupling agent, flaw detection sensitivity and scanning method. 11.4 Mark the detection area on the sketch. If there are parts that cannot be detected due to geometric restrictions, they must also be marked on the sketch. 11.5 Type, size and location of defects. 11.6 Defect grade and flaw detection conclusion.
Signatures of the flaw detector and auditor, qualification certificate number, grade and date of the flaw detector. 11.7
669
A1 testing equipment
93
JB/T6903
Appendix A
Transverse wave inspection
(Supplementary Parts)
The performance of A1.1 instruments and probes shall comply with the provisions of Articles 5.1, 5.2 and 5.3. A1.2 The combined sensitivity margin of the instrument and probe shall not exceed the maximum detection sound path of the workpiece being detected. Less than 10cB. A1.3 The shape and size of the calibration test block are shown in Figure A1 and Table A1. 40
Nominal thickness of material
25
>25～50
>50～100
>100~～150
>150 ~200
A2
Production of distance-amplitude curve
100
Figure Al
Table A1
Thickness of test block!
25
50
100
150
200
40
ApertureΦ
2.5| |tt||3.0
5. 0)
6.0
8.0
mn
Use the basic calibration test block shown in Figure A1, using the oblique The probe probes the transverse holes at the depth positions of T/4, T/2, and 3T/4 in the test block, finds out the positions of the maximum reflected wave points and marks them on the fluorescent screen. By connecting these points, the distance-amplitude curve is obtained. , A3 scanning
The oblique probe must scan at least two directions perpendicular to each other on the flaw detection surface. The probe should be continuously deflected during scanning, and the deflection angle must not be less than 15°.
A4
Defect record
JB/T6903--93
Record defects whose echo amplitude exceeds the distance-amplitude curve and determine their geometric size and position A4. 1
A4.2
Hazardous defects that the inspection personnel deem necessary to record. A5 Acceptance Standards
The acceptance standards should be agreed upon by both parties.
Flaw detection report
A6
The flaw detection report shall be in accordance with the provisions of Chapter 11 of this standard. Additional notes:
This standard is proposed by the National Valve Standardization Technical Committee. This standard is under the jurisdiction of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by Hefei General Machinery Research Institute and Kaifeng High Pressure Valve Factory. The main drafters of this standard are Yuan Rong and Wu Yongguang. 671
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