CB/T 3559-1994 Manual ultrasonic flaw detection process and quality classification of ship steel welds
Some standard content:
Shipbuilding Industry Standard of the People's Republic of China
CB/T 3559—94
Manual Ultrasonic Flaw Detection Process and Quality Classification of Ship Steel Welds
Published on February 1, 1994
Published by China State Shipbuilding Corporation
Implemented on August 1, 1994
Shipbuilding Industry Standard of the People's Republic of China
Manual Ultrasonic Flaw Detection Process and Quality Classification of Ship Steel Welds
1 Subject Content and Scope of Application
CB 1 3559—94
Service#
tReplacement of CBR21-K
CB- $178-k
This standard specifies the ultrasonic flaw detection process and weld quality classification for butt and fillet welds of ships. This standard is applicable to manual direct contact A-type pulse reflection ultrasonic flaw detection of full penetration welds of ferritic steel with a base material thickness of 6--1Gmm.
This standard is not applicable to cast and austenitic stainless steel welds, and electroslag welds without heat treatment; longitudinal welds of cylinders with an outer diameter of less than 250mm or an inner and outer diameter ratio of less than 0.8, and peripheral welds of cylinders (or pipe fittings) with an outer diameter of less than 200mm; various sizes of curved intersecting welds,||tt ||2 Reference standards
CB/13177 Specification for radiographic and ultrasonic inspection of ship steel welds ZBY344 Naming method for ultrasonic flaw detection probes ZBJ04001 Method for testing the working performance of type A pulse reflection ultrasonic flaw detection system 3 Flaw detectors
Flaw detectors must hold a qualification certificate for non-destructive testing personnel and ultrasonic testing methods approved by the ship inspection department before they can engage in the corresponding level of flaw detection work.
4 Flaw detectors, probes and system performance
4.1 Flaw detectors must be calibrated by a national statutory metrology agency before they can be used. 4. 2 The working frequency range of the probe shall be at least 1~5 MHz, the horizontal linear error shall not be less than 1%, the sublinear error shall not be less than 5%, and the dynamic range shall not be less than 26 dB. The working error of the attenuator or gain controller shall not exceed -1 dB in any 12 dB range, and the total adjustment shall not be less than 60%.
4.3 The probe shall have the marks specified in 7BY341; the horizontal axis of the sound beam shall not deviate by more than 2°, and double peaks shall not appear in the vertical direction. The measured value of the refraction angle shall not deviate from the nominal value by more than 2°, and the K value (tangent value of the refraction angle) shall not deviate by more than 0.1. The deviation value of the front distance shall not be greater than 1 m
4.4 The resolution (z value) of the probe and the oblique probe combination shall be greater than 15 dB3 when measured on the 1.5 mm×4 two holes on the CTK A1 or STB A2 test block; if measured on the 0 mm and 44 mm two holes on the CTK-1 test block, the z value shall be greater than 6 dB. 4.5 The sensitivity margin of the combination of the detector and the oblique probe should be greater than 10 dR of the measuring line (MRI.). 4.6 The horizontal linearity, combined resolution and combined sensitivity margin of the flaw detector should be checked once every month. 4.7 The front distance, refraction angle and horizontal line separation angle of the oblique probe should be checked once every week after the start of use. 4.8 The flaw detector can refer to the items specified in 4.6 and 4.7 of ZB J04 001 for retrograde risk. Approved by China State Shipbuilding Corporation on February 1, 1994, and implemented on August 1, 1994
5 Test blocks and coupling agents
CB/T 3559-94
5.1 Standard test blocks can be 1IW test blocks or other types of standard test blocks. Except for the two combined properties in 4.4 and 4.5, the remaining properties must be measured on the same standard test block. 5.2 Comparative test blocks are divided into three types: CTRB-1, CTRB2 and CTRB3 according to the thickness of the parent material of the weld to be inspected. The shape and size are shown in Appendix A (Supplement). The material should be the same as the material to be inspected or have similar acoustic properties. 5.3 After rough processing, the comparative test block shall be subjected to ultrasonic flaw detection by longitudinal wave direct contact method at a frequency greater than 2.5MHz. No defects greater than 1 equivalent are allowed.
5.4 Test holes can be added to the comparative test block as needed, but the hole layout should not interfere with the reflection of the adjacent reference hole at the corner of the test fastener. 5.5 The coupling agent should have good sound transmission performance and appropriate viscosity, and should not cause harm to the workpiece being inspected and the human body, and should be easy to clean after inspection. 5.6 The same coupling agent must be used for adjustment on the comparison test block and workpiece inspection. 6 Workpiece surface preparation
6.1 After the weld has passed the appearance inspection, whether it is a random inspection of the weld chain or a full inspection of the weld, it must be numbered and marked. 6.2 The interval time from welding to detection shall be determined in accordance with relevant requirements. 6.3 The oil stains, rust spots, and splashing oxide scale on the surface of the parent material on both sides of the weld in the detection area must be removed. The detection surface should be smooth and flat, and its width shall be determined according to formulas (1) to (5) according to the different sound path span types. 6.3.1 Full sound path (single reflection method) detection, as shown in Figure 1, the detection surface width is calculated according to formula (1) or formula (2). Wf-&
Wherein: w detection surface width.mm
---1 span;
probe back edge length mml
-parent material thickness mm:
3--angle probe refraction angle: (°).
6.3.2: Caliper (direct method) detection, as shown in Figure 2, the detection width is calculated according to formula (3) or formula (4). w&ip+a
WT'tg? +a
Wherein: w detection surface width.mmt
P-1 span,
-probe back edge length, mm;
+（2）
T-parent material thickness, mm;
βangle probe refraction angle.(°).
CB/T 3559-: 94
6.3.3 Large F full range (multiple reflection method> detection, as shown in Figure 3, the detection width is calculated according to formula (5): W1.5B+I
Where: w
Detection direction width, mm;
Weld width, mm:
L.·Probe length.mm.
7 Selection of detection frequency and probe refraction angle (or K value) 7.1 The detection frequency is selected according to Table 1. It can also be selected between 25 MHz and Table 1 according to the actual situation.
Parent material
7.2 The refracted main beam must cover the cross section of the weld to be inspected. 7.3 Butt welds are selected according to Table 2 Select,
Detection frequency
5 (or 1)
Base material thickness
>59~1:0
Detection query
Single side and double side
Single and double measurement
Grass surface effect
CB/T 3559-94
Use span
1/2 span--1 span
>1 span
172 span-1 span H
172 span mud~1 span
172 road bar
Note: 1) It is only used when the weld is wide + the front edge of the probe is long. 2) Applicable to 75 mm
Fillet welds are selected according to Table 3. The relative position of the detection surface and the probe is shown in Figure 1. 7,4
Web plate sequence T
Detection surface
Pursuit single and single side
Web plate surface single side
Panel outer single side effective side
Web plate single side single side
Panel outer single side double account
Use span
1/2 span--1 road
1/2 span~1 span
1/2 span
12 span ratio~span
12 road fold
ta）Web plate parallel
Reflection angle
70°(K3. 5:K2.0)
70°G0-(or K2. 5:
45( K1.Kl. =)*
70°:60°(or K2;K1.5)
Projection angle
(or value)
70(or K2. 5,K2.0)
7060or K2.321.5）
60\:43\or K1.5;K">
4(or K1)
a5（k1)
8Baseline adjustment
CB/T 3559
) Single side of the panel
Continued Figure 4
8.1 Use the reference hole or the semicircular test block of the same material on the comparison test block: the reflection on the arc is adjusted proportionally with the horizontal, depth or travel distance "the time base scale on the oscilloscope screen
8.2 The maximum detection distance is adjusted to at least 3/4 of the full scale of the oscilloscope screen baseline, 9 distance-amplitude curve
9.1 The distance-amplitude curve should be produced by actual measurement on the CTRB-1 or CTRB-2.CTR3 test block based on the actual detection instrument and probe, after time baseline adjustment according to the measurement distance range. bZxz.net
9.2 The original thickness of the parent material of the weld under inspection is not uniform, and the sensitivity of the distance-amplitude curve cluster is 4. Table 4
Sequence of parent material
9.3 Drawing of distance·amplitude curve cluster
ARL line
(judgment)
9.3.1 Paging of relative wave height distance coordinate method RI. line
(length measurement division line)
3-6 dh
(length measurement line)
$3-12dB
Db values of the three horizontal holes with no sound path on the CTRB test block at the same amplitude (such as oscilloscope full amplitude of 50%) are drawn on the coordinate paper, and then the curve cluster consisting of ARL., DRI. and MR1. is made according to Table 4. The schematic diagrams are shown in Figures 5 and 6. Figure 5 Schematic diagram of the self-emission of the parent material thickness umm
CB/T 3559-94
Process, mm
Figure 6 Schematic diagram of the blood line family of the parent material thickness T50mm
9.3.2 dB-panel method
Scan the 3 horizontal holes with the longest sound path on the (TRB test fast), adjust the reference echo to more than 8% of the full amplitude of the oscilloscope screen:, with this sensitivity as the benchmark, mark the amplitudes of the horizontal holes of different sound paths on the oscilloscope screen one by one, and then connect them into a test hole distance-amplitude curve (as shown in Figure?, use the attenuator on the instrument and connect 1 to make the object test AR] .DRI. MR[.At the point of Irborough, the distance amplitude curve is drawn by sliding on the two ranges
9.3.3 Amplitude surface selection
After the line is drawn by the method in 9.3.2, ARL., IRI., or MRL line is drawn on the oscilloscope screen according to Table 4 (as shown in Figure 8). If the MRL line is 20% lower than the full range of the oscilloscope screen, it is made in sections (as shown in Figure 9). Figure 8 Panel curve diagram of base material thickness T50mm
9.4 Within the acoustic system of detection, no less than three points are drawn when drawing the distance amplitude curve. 6
Figure: Schematic diagram of the curve of the sectioned lathe
10 Calibration and compensation
10.1 Calibration
CB/T3559-94
10.1.1 Detection During the process, the time baseline ratio and distance-amplitude curve shall be calibrated on the comparison test block every 4 hours, with no less than two calibration points.
10.1.2 When the time baseline drift at the calibration point exceeds the full scale + 2%, the time baseline ratio shall be recalibrated and the located defects shall be re-measured.
10.1.3 When the echo amplitude at the calibration point deviates from the original amplitude by more than 10%, it shall be recalibrated and the defects of the determined equivalents shall be re-checked. 10.2 Compensation
The transfer compensation between the comparison test block and the test piece can be measured according to the following procedures: 10.2.1 Use two probes with the same refraction angle to perform one receiving and one sending on the corresponding comparison test block (as shown in Figure 10). Adjust the secondary bottom surface reflection wave to a height H of 80% of the full scale of the oscilloscope screen (as shown in Figure 11). Indication
Figure 10 On the comparison test block, a receiving and transmitting diagram is made with a span of -1. ... Make the base material reflect wave H once or twice from the bottom surface; + is displayed on the oscilloscope screen as shown in Figure 15. CB/T 3559-94
Figure 14 Schematic diagram of the bottom reflection wave H obtained on the parent material
Shown screen
Figure 15 Schematic diagram of the bottom reflection wave H and the reflected wave II on the shown screen
Schematic diagram of the corresponding sound path point
10.2.4 Use the attenuator of the instrument to increase (or decrease) II to point P and obtain the transfer compensation dB value, as shown in Figure 15. 11 Probe scanning method
11.1 Determine the defect position, direction, shape and distinguish defect signals and false signals. Use four basic scanning methods: front and back, left and right, swing (corner) and surround (as shown in Figure [6].
's rear left scan means
's dynamic scan is used in the circular scan
11.2 To detect longitudinal defects, the front and back and left and right scans are combined into a zigzag scanning method as shown in Figure 17). The probe should move along the weld at a distance no greater than the diameter or width of the wafer, and should swing 10 to 15 degrees during movement. The moving range in the vertical welding direction should be larger than one span, which is also called dividing the moving range into two areas: half span and span (as shown in Figure 18). .iP
Change to help about, ~15\
CB/T3559-94
11.3 Detection of transverse defects should be carried out by oblique parallel scanning as shown in Figure 19. The probe is at the edge of both sides of the weld and forms an angle of 10° to 20° with the center line of the weld. It is scanned from four directions.
Continuous center line
1 - 20
11.4 Detection of comb defects in T-type fillet welds. Parallel scanning can be used. As shown in Figure 20, the probe is scanned in two directions along the weld on the panel.
Welding edge avoidance line
Lifting plate edge green line
11.5 When necessary and conditions permit, in order to detect lamellar fractures on the entire panel side of T-type corner welds, a longitudinal wave straight probe can be used to make a vertical square or horizontal square measurement along the weld on the panel as shown in Figure 21. The detection sensitivity and defect evaluation are shown in Appendix C (reference) Avoidance edge tower area
Coal male edge control line
Good welcoming support
12 Initial flaw detection
CB/T3559-94
12.1 The flaw detection sensitivity shall not be lower than the MRL line.
12.2 When the echo in the detection area exceeds the MRI line, it should be determined whether it is a defect wave based on the position, direction, scanning method, sound path and weld condition of the operating head.
12.3 Mark the area determined to be a weld defect. 13 Evaluation of flaw detection
13.1 Adjust the flaw detection sensitivity to the MR1 line and conduct further inspection on the areas marked in the initial flaw detection. 13.2 Determine the defect orientation (including direction along the weld, depth, and distance from the center of the weld section) based on the probe position of the highest echo. 13.3 Determine the area where the highest echo is located. According to the provisions of Article 13.1, move the probe left and right to measure the indicated length. 13.4 Defect indication length measurement
13.4.1 When the defect echo is located between the ARI line and the DRL line and has only one peak, it is measured by reducing the relative sensitivity by 6 dB. If there are multiple peaks, the relative sensitivity method of reducing the endpoint peak amplitude by 6 dB is used for measurement. 13.4.2 When the defect echo is located between the DRI line and the MRL line and has only one peak, it is measured by the absolute sensitivity method of reducing the peak amplitude to the MRL line. If there are multiple peaks, it is measured by the absolute sensitivity method of reducing the endpoint peak amplitude to the MRL line. 14 Detection of longitudinal welds of simplified body
Detection of longitudinal welds of simplified body is shown in Appendix B (supplement). 15 Weld quality rating
15.1 According to the wave height, indication length and distribution of defects, the weld quality is divided into V to V grades. 15.2 Defect echoes higher than the ARL line (located in the N zone) are rated as V grade, 15.3 Defect echoes lower than or equal to the MRL (located in the [>] zone are rated as V grade. 15.4 Defect echoes between the MRI line and the ARI line are rated according to the measured single defect indication length according to Table 5. Level, 5
Deep level
Single defect indication length mm
T\, minimum 8: maximum 24
T; minimum 12: 3G
Three T: minimum [R: maximum 48
T: maximum 20; maximum 60
Exceed wrinkle
The thickness of the parent material of the weld being inspected, if the thickness of the two materials of the weld is different, the thinner thickness shall prevail. —
refers to the allowable value when the base material T is less than a certain thickness. For example, for the first-grade joint, when the base material is less than 21mm, the minimum length of a single defect is allowed to be mm.
refers to the limit value when the base material is 7-1 mm thick. For example, for the second-grade joint, when the base material is greater than 72mm, the maximum length of a single defect is not allowed to be less than 24mm.
15.5 exceeds the MRI line to AR1.If the defect echo between the lines has an indication length less than 8mm, it shall be calculated as 4mm: 15.6 If the distance between adjacent defects in each direction is less than 8mm, the sum of the defects shall be used as the rating of the indication length of a single defect. 10
CR/T 3559--94
15.7 When the indication length of a single defect does not exceed the limit value in Table 5, the total length added within any GT or 150mm (whichever is smaller) of the weld length shall not exceed the limit value in Table 6.
Assessment level
Total length m
greater than N
15.8 If two defects can be partially found within any 6T or 150mm (whichever is smaller) of the weld length, the total indication length of the two defects shall be included in the total length rating.15.9 If the length of the weld to be inspected is less than 6T or 150mm (whichever is smaller), the limit values in Table 61 shall be reduced according to the product example. However, the minimum total length may be rated according to the limit value of the indication length of a single defect in Table 5.15.1 0 The inspected welds are confirmed by the inspection personnel to be hazardous defects (cracks, lack of fusion, lack of penetration) and are evaluated as V level, and are not subject to the provisions of 15.3~15. If you encounter difficulties and cannot confirm, other non-destructive testing methods can be used for comprehensive judgment. 15.11 For welds sampled in proportion, when it is confirmed that the hazardous defects are extended at the end or both ends of the inspection area (section), the inspection should be extended to the extended end, and the inspection length should be in accordance with Article 10.13 of CB/T3177. 15.12 For welds with a lower acceptance level, it shall be in accordance with Article 10 of CB/T3177. 16 Records and reports
For the inspection record format, see Appendix ID (reference). For the report format, see Appendix A (participant) of CR/I3177. 11
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