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The Code of Erection and Acceptance for Electric Power Construction Ultrasonic Inspection Section for Butt Welds of pipes
DL/T5048—95
Editor: Construction Coordination Department of the Ministry of Electric Power Industry Approved by: Ministry of Electric Power Industry of the People's Republic of China
According to the requirements of the Ministry of Electric Power Industry's Document No. 7 of Construction Quality (1994), the Ministry's Electric Power Construction Research Institute organized relevant experts within the department to form a code revision group to revise the "Technical Code for Construction and Acceptance for Electric Power Construction (Ultrasonic Inspection Section for Butt Welds of pipes)" SDJ67—83.
The revised code retains the provisions of the original code that have been effectively implemented in long-term practice. The flaw detection process and quality standards of ultrasonic flaw detection of small-diameter pipe welded joints have been tried out in the power system for one year in the form of guidelines. After extensively listening to the opinions of relevant domestic units and referring to relevant foreign standards, the revised provisions emphasize operability and accuracy and are included in the specification as an independent chapter. This specification shall be implemented from April 1, 1996. From the date of entry into force, this specification will replace SDJ67-83 at the same time. Appendix A, Appendix B, Appendix C, Appendix D, Appendix E, Appendix F, Appendix G, Appendix H and Appendix J of this specification are all standard appendices. Appendix K is a prompt appendix. This specification is proposed and managed by the Electric Power Construction Research Institute of the Ministry of Electric Power Industry.
The drafting units of this specification are: Electric Power Construction Research Institute of the Ministry of Electric Power Industry, Wuhan University of Hydraulic and Electric Power, Jiangsu Electric Power Construction Company No. 1, Anhui Electric Power Construction Company No. 1, Hubei Electric Power Construction Company.
The main drafters of this specification are: Chen Ping, Mao Senxiang, Xu Yacheng Shi Rucai, Wang Huanming, Li Qijie.
1 Scope
This specification specifies the general methods for inspecting defects in welded joints, determining the location, size, equivalent and defect evaluation of defects, and the classification method of flaw detection results.
This specification is applicable to the ultrasonic flaw detection of single-sided welded and double-sided formed welded joints of steel pressure pipes with a wall thickness of 4 to 120 mm and a nominal diameter greater than or equal to 32 mm when manufacturing, installing and repairing equipment in power systems.
This specification is not applicable to the ultrasonic flaw detection of welded joints of cast steel and austenitic stainless steel, as well as the flaw detection of friction welded joints of small-diameter pipes with a wall thickness of 4 to 14 mm and a nominal diameter of 32 to 89 mm.
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 valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards.
ZBJ04001-84A pulse reflection ultrasonic flaw detection system T working performance test method
ZBY230-84A pulse reflection ultrasonic flaw detector general technical conditions
ZBY231-84
Ultrasonic flaw detection probe performance test method
4 No. 1 standard test block technology for ultrasonic flaw detection
ZBY232-84
GB11345---89
and classification of flaw detection results
Manual ultrasonic flaw detection method for steel welds
2 Technical specifications for construction and acceptance of electric power construction
DL5007--92
(Welding of thermal power plants)
3 Flaw detection personnel
3.1 Qualification
Flaw detection personnel must obtain a qualification certificate issued by the Qualification Assessment Committee for Nondestructive Testing Personnel in the Electric Power Industry, and the flaw detection report must be issued by ultrasonic flaw detection personnel of level II or above. 3.2 Non-standard flaw detection
Flaw detection personnel shall conduct flaw detection in accordance with the requirements of this specification. If flaw detection methods other than those specified in the specification are used, they shall be approved by the relevant departments in advance and indicated in the report.
3.3 Safety
Ultrasonic flaw detection must comply with on-site safety regulations and other relevant regulations.
3.4 ​​Flaw Detection Conditions
When the flaw detection conditions do not meet the process requirements of this specification or do not meet the safe working conditions, the flaw detector has the right to stop working and continue flaw detection after the conditions are improved and meet the requirements. 4 Flaw Detector and Probe
4.1 Flaw Detector
4.1.1 The performance indicators and test methods of the flaw detector shall comply with the corresponding provisions of ZBY230 "General Technical Requirements for Type A Pulse Reflection Ultrasonic Flaw Detectors" and ZBJ04001 "Test Methods for Working Performance of Type A Pulse Reflection Ultrasonic Flaw Detection Systems". Its operating frequency is 1 ~ 5MHz,
4.1.2 Combined sensitivity of the instrument and the oblique probe: At the maximum sound range of the weld to be detected, the effective flaw detection sensitivity margin shall not be less than 6dB. 4.1.3 Combined resolution: It should be able to separate the reflected signals of the two holes $50 and $44 on the standard test block in Appendix A. When the reflected amplitudes of the two holes are the same, the difference between the peak and the trough should not be less than 6dB. 4.2 Probe
4.2.1 The performance of the probe must be measured in accordance with ZBY231 "Test Methods for Performance of Ultrasonic Flaw Detection Probes".
4.2.2 Requirements for the horizontal deviation angle of the sound beam of the oblique probe: Place the probe on the standard test block to detect the edge. When the reflected amplitude is the largest, the angle between the center line of the probe and the edge to be measured should be within the range of 90°±2°.
4.2.3 The main sound beam of the oblique probe in the vertical direction: There should be no obvious double peaks or multiple peaks.
4.2.4 The allowable deviation of the center frequency of the probe is ±0.5MHz. 5 Test Blocks
5.1 Standard Test Blocks
The shapes and dimensions of standard test blocks are shown in Appendix A. The technical requirements for test block manufacturing shall comply with the provisions of ZBY232 "Technical Conditions for No. 1 Standard Test Blocks for Ultrasonic Flaw Detection". This test block is mainly used for the determination of the performance of flaw detectors, probes and systems.
5.2 Comparison Test Blocks
5.2.1 The shapes and dimensions of comparison test blocks are shown in Appendix B. 5.2.2 Comparison test blocks are made of steel that is the same as or has similar acoustic properties to the pipe being inspected. When the detection surface and side of the test block are inspected with a straight probe at a frequency of 2.5MHz or above, there shall be no defect echo greater than 1/4 of the height of the reflection echo amplitude of the $2 flat bottom hole at 20mm from the detection surface.
5.2.3 The shapes and dimensions of the sawtooth groove comparison test block are shown in Appendix C. This test block is made of the pipe being inspected and is used for comparative determination of defects at the root of welded joints.
5.2.4When the radius of curvature of the flaw detection surface R≤W2/4 (W is the probe width), a comparison test block with the same curvature as the flaw detection surface should be used. The arrangement of the reflector can be determined with reference to the comparison test block, and the test block width should meet the following requirements:
where b is the test block width, mm;
A is the wavelength, mm;
A sound path, mm;
D is the effective diameter of the sound source, mm.
5.2.5In order to check the sensitivity and scanning linearity during on-site flaw detection, the portable test block shown in Appendix D can be used. 5.2.6Other types of test blocks can be used under the condition that the sensitivity requirements are met, but they should be approved by the relevant departments in advance and indicated in the report.
6 Process requirements
6.1 Preparation before flaw detection
Before flaw detection, the name, material, specification, welding process, heat treatment, groove type (the length of the inner groove on one side is not less than 0.6), and the calibration of the center position of the welded joint should be understood. Note: It is the pipe wall thickness, the same below.
6.2 Welded joints
6.2.1 The surface quality and external dimensions of the welded joint must be inspected and qualified.
6.2.2 Spatter, rust, oxides and oil stains should be removed from both sides of the welded joint, and the surface should be polished smooth. The polishing width should be at least the moving range of the probe (see Figure 7.2.2 and Figure 7.2.3). 6.2.3 The base material on both sides of the welded joint should measure the wall thickness of the pipe before flaw detection, at least one point every 90°. 6.2.4 Welded joints that require heat treatment after welding should be flaw detected after heat treatment.
6.3 Coupling agent
The coupling agent should have good wetting ability and sound transmission performance, and be non-toxic, non-corrosive and easy to remove. Commonly used coupling agents are engine oil, glycerin and paste.
6.4 Flaw detection contact surface
The working surface of the probe should be in close contact with the outer surface of the pipeline and should be ground if necessary. The incident point and refraction angle of the probe should be re-measured after grinding.
7.1 Probe selection and scanning speed adjustment
7.1.1 When ultrasonically testing pipeline welded joints, the refraction angle of the oblique probe should be selected based on the principle that the center line of the direct wave sound beam can scan at least 2/5 of the thickness of the welded joint (refer to Table 7.1.1). When detecting root defects, it is not appropriate to use a probe with a refraction angle of about 60°. Selection of oblique probe refraction angle
Pipe wall thickness
14 ~46
>46 ~100
>100 ~ 120
Probe refraction angle
60~45; 45 and 60, 45 and 70 are used together
60 and 45 are used together
7.1.2 The probe frequency is generally 2.5MHz. When the pipe wall thickness is thin, it is easy to use a SMHz probe.
7.1.3 When inspecting pipeline welding joints, the scanning speed can be adjusted on the standard test block or the comparison test block. 7.1.4 The scanning speed ratio is determined according to the workpiece thickness and the selected probe angle.
7.2 Inspection position and probe movement range
7.2.1 It is generally required to inspect from both sides of the welding joint. When the weld joint can only be inspected from one side due to conditions, two or more approved probes with different refraction angles should be used for inspection and the inspection report should be noted.
7.2.2 When the direct wave and primary reflection wave method are used for inspection, the probe movement area should be greater than 1.25p (see Figure 7.2.2). 1.25 years
Figure 7.2.2 Probe movement area during inspection of general pipeline welded joints
p=2ttgβ
Where p span, mm;
Pipe wall thickness, mm;
β--refraction angle,.
7.2.3 When the pipe wall is thick (wall thickness greater than 50mm), direct wave inspection is used, but a probe with a large refraction angle is required for inspection (see Table 7.1.1). The probe movement area should be greater than 0.75p (see [Figure 7.2.3).
Figure 7.2.3 Thick-walled pipe welded joint
Probe moving area during flaw detection
7.2.4 If transverse defects need to be detected, the welded joint with the excess height removed should generally be tested.
7.3 Inspection of parent material
7.3.1 The parent material area where the sound beam passes through should be inspected with a straight probe to determine whether there is delamination or other types of defects that affect the interpretation of the oblique flaw detection results. This inspection is only recorded and does not belong to the acceptance inspection of the parent material. The key points of the inspection are as follows:
1 Method: Contact pulse reflection method, using a straight probe with a frequency of 2~5MHz and a chip diameter of 10~25mm; Sensitivity: Adjust the secondary bottom wave of the defect-free area to the full scale of the fluorescent screen;
Record: Any part where the defect signal exceeds 20% of the full scale of the fluorescent screen should be marked on the work surface and recorded.
7.3.2 When detecting thinner pipes or near-surface defects, if the single crystal probe cannot achieve the required near-surface resolution, a dual crystal probe can be used.
7.4 Scanning method
-Generally, the basic scanning method is to move the probe in a rectangular shape along the weld joint. During scanning, the distance s moved by the probe each time shall not exceed the diameter of the probe wafer. While keeping the probe moving in a direction perpendicular to the center line of the weld, a small angle swing should be made according to the curvature of the pipe diameter (see Figure 7.4.1). 7.4.2 In order to determine the position, direction, and shape of the defect, observe the dynamic waveform of the defect, or distinguish between the defect signal and the false signal, the front-back, left-right, corner scanning methods can be used (see Figure 7.4.2). 7.4.3 The flaw detection speed should be less than 150mm/s. 1568
Swing about 10~15%
Figure 7.4.1 Basic scanning method of the probe
Figure 7.4.2 Other scanning methods
7.5 Drawing of distance-amplitude curve
7.5.1 In addition to being drawn by the flaw detector itself, the distance-amplitude curve should be drawn based on the data measured by the flaw detector and the probe on the comparison test block (see Appendix E). The curve consists of RL (rejection line), SL (quantification line) and EL (evaluation line). The area between EL and SL is called I zone, the area between SL and RL is called II zone, and the area above RL is called III zone, as shown in Figure 7.5.1.
Rejection line (RL)
Quantitative line (SL.)
Evaluation line (EL)
Distance, mm
Figure 7.5.1 Schematic diagram of distance-amplitude curve
7.5.2 The sensitivity of distance-amplitude curve for different pipe wall thicknesses shall be as specified in Table 7.5.2.
7.5.3 The calibration of distance-amplitude curve shall be carried out on the comparison test block with the flaw detector and probe used, and the calibration shall be not less than two points. 7.5.4 During flaw detection, due to the influence of coupling loss, material attenuation and internal and external curvature on the surface of the pipe fitting, comprehensive compensation shall be made for the flaw detection sensitivity, and the comprehensive compensation amount must be included in the distance-amplitude curve. For the measurement method of compensation, please refer to Appendix F.
7.5.5 The flaw detection sensitivity shall not be lower than the EL line, and attention shall be paid to the calibration of the flaw detection sensitivity during the flaw detection process. Pipe wall thickness
>14 ~ 46
>46 ~-120
Sensitivity of distance-amplitude curve Table 7.5.2 Evaluation line (EL) Quantification line (SL) Judgment line (RL) $3×40-
$3×40-
$3×40
$3×40~
$3×40-
3× 40dB
Note: For the sensitivity of the distance-amplitude curve when the pipe wall thickness is less than or equal to 14mm, see Table 9.3.2.
7.6 Quantification of defects
7.6.1 The defect reflection wave signal appearing between the SL line and the SL line to the RL line during the flaw detection shall be measured for the amplitude and defect indication length
7.6.2 Determination of defect amplitude: Move the probe to the position where the maximum reflection wave signal appears in the defect, and determine its area in the distance-amplitude curve according to the amplitude.
7.6.3 Determination of defect indication length:
When the defect reflection wave signal has only one high point and the sound beam width at the defect is less than the defect length, the defect indication length shall be measured by reducing the relative sensitivity by 6dB (see Figure 7.6.3-1). Maximum reflection wave
Probe moving length.mm
Defect indication length
Figure 7.6.3-1 Relative sensitivity length measurement method
During the movement of the probe, when the defect reflection wave signal fluctuates and has multiple high points, and the reflection wave radiation at the end of the defect is located at the SL line or zone II, the end point peak method is used to measure the defect indication length (that is, during the movement of the probe, the distance between the maximum values ​​of the reflection wave signals at both ends of the defect is determined as the defect indication length, see Figure 7.6.3.2).
7.7 Defect positioning
7.7.1 When the defect reflection wave signal is found during the flaw detection, the pipe wall thickness at that location should be accurately measured.
7.7.2 The defect position is indicated by the position of the maximum reflection wave signal of the defect displayed on the fluorescent screen. According to the corresponding position of the probe and the position of the reflection wave signal on the fluorescent screen, the position of the defect along the direction of the welding joint is determined; the vertical distance from the defect to the flaw detection surface and the horizontal distance from the defect to the probe shooting point and other defect position parameters. Defect indication length
Figure 7.6.3-2 End point peak length measurement method
7.7.3 One of the two values ​​of the depth and horizontal distance of the defect can be directly read from the position of the maximum reflection wave signal of the defect on the fluorescent screen, and the other value can be obtained by calculation method, curve method, drawing method or defect positioning ruler.
7.7.4 When the initial inspection finds a defect that is not allowed to exist, the refraction angle and flaw detection sensitivity of the probe must be checked, and the flaw detection must be evaluated after the flaw detector is readjusted.
7.8 Defect evaluation
7.8.1 If the maximum reflection wave signal is located in the defect sub-area, its indication length is less than 10mm, it shall be calculated as 5mm.
7.8.2 When the distance between two adjacent defects is less than 8mm, the sum of the indication lengths of the two defects shall be taken as the indication length of a single defect. 7.8.3 Comparative determination of root incomplete penetration: When root defects are found during flaw detection and confirmed as incomplete penetration through comprehensive analysis, use an oblique probe with a refraction angle of 45°50° and a frequency of 5MHz, and adjust the reflected wave amplitude of the 1.5mm deep through groove on the sawtooth groove comparison test block in Appendix C to 50% of the full scale of the fluorescent screen as the contrast sensitivity for comparative determination.
7.8.4 The nature of the defect can be determined by changing the probe angle or scanning method according to the characteristics and location of the defect reflection wave signal, and combining the welding process for comprehensive analysis.
8 Quality Standards
8.1 Assessment Unit
The quality of pipeline welding joints is assessed by each welding joint, and the equivalent number calculation is in accordance with the provisions of DL5007 "Technical Specifications for Construction and Acceptance of Electric Power Construction (Welding of Thermal Power Plants)". 8.2 Recording defects
When inspecting pipeline welding joints, if the reflection wave amplitude of non-crack defects reaches the EL line or I zone, it should be recorded but not used as quality assessment. The defect location record is shown in Appendix 1 and Appendix K. 8.3 Excessive defects
8.3.1 When any of the following defects exist in a welded joint, the welded joint shall be rated as Grade 1.
When the defect reflection amplitude is located on the RL line or Zone III. When the defect reflection amplitude is located on the SL line or Zone I, and the defect indication length (corrected arc length in the circumferential direction) exceeds the Grade ⅡI provisions in Table 8.3.1-1. When the cumulative indication length of the defect exceeds the Grade Ⅱ provisions in Table 8.3.1-2 after correction.
When one of the reflection wave signals of dense defects reaches above the SL line.
When the root incomplete penetration defect depth or length exceeds the Grade Ⅱ provisions in Table 8.3.1-3.
Allowable defect indication length
Quality grade
L = 1/3t, but
Table 8.3.1-1
L = 2/3t, but
the minimum can be 10. The minimum can be 12, the maximum
defect indication length L:
no more than 30
no more than 50
Note: For welded joints with unequal pipe wall thickness, the thickness of the thinner wall pipe shall be taken. Cumulative indication length of defects allowed
Table 8.3.1-2
Quality grade
Within 10t range
After correction, the sum of the cumulative indication length
is less than or equal to
Within 5t range, the sum of the cumulative indication length
is less than or equal to "
Allowable range of root incomplete penetration defects
Table 8.3.1-3
Quality grade
Contrast sensitivity
Deep 1.5mm saw
Tooth-shaped groove
Deep 1.5mm saw
Defect indication length
Less than or equal to 10% of the weld circumference
Less than or equal to
Tooth-shaped groove + 4dB 15% of the seam circumference
8.3.2 Contrast of root incomplete penetration:
When the defect reflection amplitude is greater than or equal to the contrast sensitivity reflection amplitude adjusted by the sawtooth groove test block, it should be evaluated as unqualified. When the defect reflection amplitude is less than the contrast sensitivity reflection amplitude adjusted by the sawtooth groove test block, use the end point 14dB method to measure the defect indication length L, and convert it into the length of incomplete penetration at the root according to the following formula 1, and then evaluate according to 8.3.1. 1 = L(D - 2t)/D (mm)
Where D-
Pipeline outer diameter, mmc
8.4 Dangerous defects
If the inspector can determine that the nature of the defect is a dangerous defect such as cracks or lack of fusion during the flaw detection, it is not subject to the restrictions of Article 8.3 and the welded joint should be evaluated as unqualified.
Unqualified welds should be repaired, and the repaired parts and the parts affected during the repair should be re-inspected. The re-inspection shall be carried out according to the original flaw detection conditions, and the quality assessment shall be in accordance with Articles 8.3 and 8.4.
9 Ultrasonic flaw detection of small-diameter pipe welded joints
9.1 Flaw detector, probe and system performance
9.1.1 The probe shall meet the following requirements:
The probe shall meet the requirements of small-diameter pipes with large inner and outer wall curvatures and thin pipe walls (the specifications are: wall thickness 4~14mm, outer diameter 32 ~89mm). A single crystal shear wave probe with high damping and short front should be used.
The probe chip size is generally not more than 6mm × 6mm.
The distance between the front and rear of the probe is less than or equal to 5mm, the deviation is less than or equal to 0.5mm, and the operating frequency is 5MHz. 9.1.2 The probe used should have good matching performance with the flaw detector. Under the condition of flaw detection sensitivity, the initial pulse width of the probe should be as small as possible, generally less than or equal to 2.5mm (equivalent to the depth in steel).
9.1.3 In order to improve the reliability of root defect detection results, it is recommended to use a shear wave dual crystal focusing probe or a flat chip dual tilt TR shear wave probe.
9.1.4 The selected shear wave oblique probe should meet the requirement that the direct wave can scan more than 1/4 of the wall thickness of the welded joint. The refraction angle should be determined according to the wall thickness. For flaw detection of welded joints with different wall thicknesses, refer to Table 9.1.4.
Recommended probe angle
Pipe wall thickness
>8 ~14
Probe refraction angle
9.1.5When the combined sensitivity can meet the sensitivity requirements of the secondary reflection wave method, the chip size of the probe can be 10mm×10mm or 8mm×9mm, the front distance can be 10mm, the frequency is 2.5～5MHz, and a probe with a chip size of 6mm×6mm is recommended for positioning.
9.1.6The contact surface of the probe must be in close contact with the outer surface of the pipe, and the gap between its edge and the outer surface of the pipe should not be greater than 0.1mm (as shown in Figure 9.1.6). The probe surface can be made in close contact with the outer surface of the pipe by laying fine sandpaper on the surface of the pipe and gently grinding it along the axial direction.
Figure 9.1.6 Schematic diagram of the gap between the edge of the probe contact surface and the outer surface of the pipe
9.1.7 In addition to the above requirements, the rest refer to the relevant provisions of Chapter 4. 9.2 Test block
9.2.1 Special test block: used to measure the system performance of the flaw detector and the probe and the adjustment of the scanning speed and sensitivity. Its shape and size are shown in Appendix G. According to the change of the curvature of the pipe, the test block is divided into 4 blocks, which can be selected according to the specified range of Table G when used. 9.2.2 Test block for measuring compensation amount: In the flaw detection of small-diameter pipe welding joints, the flaw detection sensitivity needs to measure the surface acoustic energy loss caused by the material attenuation and the roughness of the workpiece surface and the coupling condition, and also the acoustic energy scattering loss caused by the large internal curvature. Therefore, in the flaw detection of small-diameter pipes, the compensation amount must be measured, and the sensitivity must be corrected according to the measurement results. Refer to Appendix H for the test block for measuring the compensation amount. 9.3 Process and flaw detection requirements
9.3.1 The width of the welded joint height should meet the following requirements: 3
s≤β-210
Where β is the refraction angle of the probe,;
lo is the front edge length of the probe, mms
S Width of height, mm.
9.3.2 When flaw detection is performed on welded joints of small diameter pipes, the sensitivity of the distance-amplitude curve shall be in accordance with the provisions of Table 9.3.2.
9.3.3 The scanning sensitivity shall not be less than 2×15-18dB. 9.3.4 The sensitivity of length measurement is $2×15—18dB. Pipe wall thickness
≥4~8
Sensitivity table of distance-amplitude curve 9.3.2
Evaluation line (EL) Quantification line (SL) Scrap line (RL) $2 × 15-
$2×15-
$2×15-
9.3.5 During flaw detection, use direct wave and primary reflection wave method to perform circumferential scanning of the entire inspection area on both sides of the welded joint. 9.3.6 When using a probe with an angle of more than 70°, pay attention to identifying the interference signal of the surface wave.
9.3.7 When the surface of the pipe is relatively rough, it should be polished. 9.3.8 For the rest, refer to the relevant provisions of Chapters 6 and 7. 9.4 Quality standard
9.4.1 According to the type of defects in the welded joint, the size of the defect amplitude and the indication length of the defect, the quality of the welded joint is divided into qualified and unqualified categories.
9.4.2 If the flaw detector can determine that it is a dangerous defect such as cracks, unfused grooves, unfused layers or dense defects, it will be evaluated as unqualified.
9.4.3 If the defect reflection amplitude is greater than or equal to Φ2×15-4dB, it will be evaluated as unqualified. wwW.bzxz.Net
9.4.4 When measuring the length at a sensitivity of $2×15-18dB, if the defect indication length is greater than 10mm, it will be evaluated as unqualified. 10 Technical Files
10.1 The technical file should include technical information such as the pipeline system diagram marked with the welding joint number, groove type, flaw detection report and flaw detection record. The flaw detection report and flaw detection record form can be referred to Appendix J. 10.2 After the installation (or maintenance) of the unit is completed, the flaw detection report and flaw detection record should be compiled into a book and filed for unified storage. Appendix A Standard test block
(Standard Appendix)
The standard test block used for flaw detection of pipeline welding joints adopts CSK1B test block, and its shape and size are shown in Figure A. Appendix B Comparison test block
(Standard Appendix)
When flaw detection of pipeline welding joints, RB-3 comparison test block is adopted, and its shape and size are shown in Figure B.
Dimension tolerance is too 0.1
The verticality of each side is not more than 0.05
Figure A (SK-1B test block
Figure BRB-3 comparison test block
Note: 1. Dimension tolerance ±0.1:
2. The verticality of each side is not more than 0.1;
3. The surface roughness is not more than 6.3μm;
4. The parallelism of the standard hole processing surface is not more than 0.05. Appendix C Comparative test block for defects at the root of welded joints (Appendix to the standard)
The SDⅢ type comparative test block is used for comparative determination of defects at the root of pipe welded joints. The type is shown in Figure C. Appendix D Portable test block
(Appendix to the standard)
The portable test block used on site can be selected according to needs. For example, Figure D1 and Figure D2 are SDV type test blocks and IIW2 type test blocks, which can be selected.
Appendix E Preparation of distance amplitude curve
(Appendix to the standard)
<45°+1°
All 3.2
.5±0.
Figure C SD-l type comparative test block
Figure D-1
140°50°
SD-IV type test block
E1.1The comparative test block in Appendix B is used.
El.2When RW
, use a comparison test block with the same or similar curvature of the flaw detection surface as the pipe
flaw detection surface. E2 Drawing steps
(The distance-amplitude curve can be drawn on coordinate paper or on the instrument panel)
F2.1 Adjust the test range to the maximum detection range used for flaw detection, and adjust the time baseline scanning ratio according to the depth (horizontal or sound path method).
3540-5
Figure D-2IIW2 type test block
E2.2 Select a suitable comparison test block according to the thickness and curvature of the workpiece, select the horizontal hole on the test block with the same or similar hole depth as the flaw detection depth as the first basic hole, place the probe on the flaw detection surface of the test block so that the sound beam points to the hole, and adjust the probe position to find the highest reflection wave of the horizontal hole. E2.3 Adjust the gain or attenuator so that the reflected wave amplitude is a certain height on the scale of the fluorescent screen (60% of the full scale), and this wave amplitude is the "reference wave height".
E2.4 Adjust the attenuator, measure other horizontal holes in turn, and find the maximum reflected wave height, and record the amplitude of each reflected wave respectively. E2.5 Use the wave amplitude as the ordinate and the detection distance as the abscissa to plot the data recorded in E2.3 and E2.4 on the coordinate paper. E2.6 Connect each point into a curve and extend it to the entire detection range. Draw a horizontal line from the nearest detection point to point 0. This curve is the reference line of the distance-wave amplitude curve of the $3 horizontal hole.
F2.7 According to the sensitivity specified in the text, draw RL, SL and EL respectively under the reference line, and mark the wave partitions. E2.8 In order to facilitate the sensitivity verification of on-site flaw detection, while measuring the above data, a reference reflector on the portable test block used on site can be measured, and its reflected wave position and reflected wave amplitude can be recorded and marked on the distance-wave amplitude curve. Appendix F Compensation measurement test block
(Standard Appendix)
F1.1 Make a test block with the same material, specification and surface roughness as the pipe to be tested (see Figure F1.1).
F1.2 Drill a $3mm×40mm horizontal hole on the test block. When the pipe wall thickness is less than or equal to 25mm, drill one hole, t/2 away from the inner wall (see Figure F1.1-1); when the pipe wall thickness is greater than 25mm, drill two holes, t/4 and 3/4t away from the inner wall respectively (see Figure F1.1-2).
43×40
Figure F1.1-1 Compensation test block
2×$3×40
Figure F1.1-2 Compensation test block
Note: 1. Dimension tolerance ±0.1;
2. The verticality of each side is not greater than 0.1;
3. Surface roughness is not greater than 6.3μm;
4. The parallelism of the standard hole surface is not greater than 0.05. F2 Measurement method
F2,1 Use the instrument and probe to make a distance-amplitude curve on the RB comparison test block.
F2.2 The same instrument and probe are used to detect the Φ3mm×40mm horizontal hole on the test block under the same initial sensitivity conditions. The direct wave detects the lower hole and the primary reflected wave detects the upper hole (Figure F1.1-2). If the test block has only one hole, the same horizontal hole shall be tested (Figure F1.1-1); adjust the amplitude to the specified height, and then read the decibel number N of the attenuator.
F2.3 Find the decibel number N of the same distance on the distance-amplitude curve, and the comprehensive compensation AN is determined by the following formula: AN = N - N'(dB)
Appendix G Special test block for ultrasonic flaw detection of small-diameter pipe welding joints
(Standard Appendix)
Special test block for ultrasonic flaw detection of small-diameter pipe welding joints, as shown in Figure G. There are 4 test block sets in total, and their applicable scope is shown in Table G. The material and surface condition requirements are the same as those in Articles 5.1 and 5.2.1. Applicable scope of special test blocks
Test block number
Applicable scope
932$35
#38-441
$44.5±48
460~176
Applicable scope
Figure G Special test block for ultrasonic flaw detection of small diameter pipe welding joints Note: 1. Dimension tolerance ±0.1;
2. The verticality of each side shall not exceed 0.1;
3. Surface roughness shall not exceed 6.3μm
4. The parallelism of the standard hole processing surface shall not exceed 0.05. Appendix H Test block and compensation for ultrasonic flaw detection sensitivity of small-diameter pipe welded joints (Standard Appendix)
H! Measurement of acoustic energy loss on the outer surface of the pipe when direct wave flaw detection is used H1.1 The probe is placed on the arc surface of the test block in Figure G, and the Φ2 hole with the same or similar depth as the wall thickness of the pipe to be detected is measured. The highest reflected wave is adjusted to 80% of the full scale of the fluorescent screen and the decibel value of the attenuator is recorded.
H1.2 Under the condition of keeping the instrument probe unchanged, the probe is placed on the outer surface of the arc of the test block in Figure H, and the reflected wave of the probe sound beam at the center of the arc section with an inner surface r of 1mm on the outer surface of the arc groove is adjusted to 80% of the full scale of the fluorescent screen, and the decibel value of the attenuator is recorded.
H1.3 Compare the decibel values ​​measured by the methods described in H1.1 and H1.2. The difference is the acoustic energy loss on the outer surface of the pipe when direct wave flaw detection is used, that is, the compensation value.
H2 Measurement of acoustic energy loss on the inner and outer surfaces of pipes when using the single reflection wave method for flaw detection
H2.1 The probe is rotated on the arc surface of the test block in Figure G, and the Φ2 hole with the same or similar depth as the wall of the pipe being detected is measured. The highest reflected wave is adjusted to 80% of the full scale of the fluorescent screen and the decibel value of the attenuator is recorded.
Figure H Reference diagram for measuring compensation test block
Note: 1. The material, R, and t of the test block are the same as those of the pipe being detected; 1±o.1
2. The roughness of the flaw detection surface of the test block is the same as that of the polished pipe. H2.2 Under the condition of keeping the instrument probe unchanged, the probe is placed on the outer surface of the arc of the test block in Figure H. The inner surface of the test block is the center of the arc section of 1mm. The reflected wave of the probe sound beam on the outer surface of the arc groove is adjusted to 80% of the full scale of the fluorescent screen, and the decibel value of the attenuator is recorded.
H2.3 Compare the decibel values ​​measured by the methods described in H2.1 and H2.2. The difference is the compensation value of the sound energy loss on the inner surface of the pipe when the single reflection wave method is used for flaw detection.
Appendix" Flaw Detection Report and Flaw Detection Record Form (Standard Appendix)
Ultrasonic Flaw Detection Report of Pipeline Welding Joint
Project Name
Pipeline Name
Welding Seam Number
Welding Material
Groove Type
Welding Method
Name and Code of Welder
Heat Treatment Specification
Table J-1
Report Number:
Instrument Model
(Number)
Test Block Type
Flaw Detection Sensitivity
Evaluation and Treatment Opinion:
Reviewer Name:
Qualification:
Inspection unit: (stamp)
Weld number:
Defect location
(point)
Flaw detection strip
Probe specification
Refraction angle
Couple agent
Sensitivity compensation
Inspector name:
Qualification:
Inspection technology leader:
Form filler:
Ultrasonic flaw detection record of pipeline welding joint
Probe-weld defect
Record indication
Defect indication
Defect amplitude
$3× 40± dB
Chip size
Defect nature
Table J-22 The difference between the decibel values ​​measured by the two methods is the compensation value of the sound energy loss on the inner surface of the pipe when the single reflection wave method is used for flaw detection.
Appendix" Flaw Detection Report and Flaw Detection Record Form (Standard Appendix)
Ultrasonic Flaw Detection Report of Pipeline Welding Joint
Project Name
Pipeline Name
Welding Seam Number
Welding Material
Groove Type
Welding Method
Welder's Name and Code
Heat Treatment Specification
Table J-1
Report Number:
Instrument Model
(Number)
Test Block Type
Flaw Detection Sensitivity
Evaluation and Treatment Opinion:
Reviewer Name:
Qualification:
Inspection unit: (stamp)
Weld number:
Defect location
(point)
Flaw detection strip
Probe specification
Refraction angle
Couple agent
Sensitivity compensation
Inspector name:
Qualification:
Inspection technology leader:
Form filler:
Ultrasonic flaw detection record of pipeline welding joint
Probe-weld defect
Record indication
Defect indication
Defect amplitude
$3× 40± dB
Chip size
Defect nature
Table J-2
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