This standard specifies the basic requirements for radiographic and ultrasonic inspection of ship steel structure welds. This standard applies to the inspection of full penetration welds of ship hulls, frames, marine pressure vessels and piping systems. CB/T 3177-1994 Rules for Radiographic and Ultrasonic Inspection of Ship Steel Welds CB/T3177-1994 Standard download decompression password: www.bzxz.net

Shipbuilding Industry Standard of the People's Republic of China
CB/T 3177-94
Radiographic and Ultrasonic Inspection Rules for 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
Radiographic and Ultrasonic Inspection Rules for Ship Steel Welds
Subject Content and Scope of Application
CB/T3177-94
Classification Number: U06
Replaces CB3177-83
This standard specifies the basic requirements to be followed when implementing radiographic and ultrasonic inspections of ship steel structure welds. This standard applies to the inspection of full penetration welds of ship hulls, frames, marine pressure vessels and piping systems. Reference standards
CB/T3558 Radiographic process and quality grading of ship steel weldsCB/T3559 Manual ultrasonic flaw detection process and quality grading of ship steel welds 3 Weld acceptance levels
According to the type, structure and location of ship products, there are four acceptance levels, see the table below. Product types and weld locations
Longitudinal and circumferential seams of the shell, headers and pipes of Class 1 marine boilers and pressure vessels; butt welds of independent tanks, tanks and cabinets of dangerous chemical carriers such as liquefied natural gas and petroleum gas
Longitudinal and circumferential seams of the shell, headers and pipes of Class I marine boilers and pressure vessels; end welds of important parts of the shell within 0.6L of the swelling of the ship with a length of L>150m;
Special ship types with a length of L≤150m (such as the longitudinal structure type of the deck with large hatch opening); end welds of important parts of the shell within 0.6L of the swelling and within 0.4L of the swelling of the marine fishing ship with a length of L≥45m; all longitudinal and transverse butt welds of hoisting
Marine Class II Longitudinal and circumferential seams of pressure vessel shells and pipelines; terminal welds of the structure and non-important parts within the 0.6L expansion of the ship with a length of L>150m; terminal welds of the shell plate outside the 0.6L expansion, terminal welds of important parts of the inner shell of the 0.6L expansion of the ship with a length of L between 65 and 150m, and other butt and fillet welds specified in the classification and construction rules for steel seagoing ships: terminal welds of the inner structure and non-important parts of the marine fishing vessel with a length of L≥45m, 0.4L expansion of the ship; terminal welds of the shell plate outside 0.4L and the important parts of the inner shell of the ship with a length of L<45m, 0.4L expansion of the ship, and terminal welds of the shell plate outside 0.61. and the inner structure and non-important parts of the ship with a length of I between 65 and 150m. Shell end welds for ships with a length of L<65m;
Structures within 0.4L of the swelling part, non-important parts and shell end welds outside 0.4L of the swelling part of marine fishing vessels with a length of L<45m Note: 1) L refers to the length between two vertical lines.
2) Important parts of the shell refer to the top strake on the navigation side, this strake, strength deck, and keel plate. China State Shipbuilding Corporation approved the acceptance level on February 1, 1994
Implementation on August 1, 1994
CB/T3177—94
The inspector marks the position of each inspection area (section). If the actual length of the weld to be inspected is less than 300mm, the actual length shall be used as the inspection area (section). At the longitudinal and transverse cross welds, the inspection area (section) shall be parallel to the transverse weld. 5.2 When inspecting by ultrasonic method, the length of each inspection area (section) shall not be less than 450mm. If the actual length of the inspected weld is less than the above provisions, the actual length shall be used as the inspection area (section). 5.3 The number of inspection areas (sections) is obtained by dividing the total length of the inspected weld by 300mm. 5 Determination of inspection method
The ordering party, design department, surveyor and manufacturer shall jointly discuss and determine the inspection method used for each inspection area (section) based on the material, plate thickness, weld type and location, and weld quality record stability, and list the detailed table. 7
Non-destructive testing personnel
7.1 When inspecting by radiography, a qualification certificate for ship non-destructive testing (radiography) personnel recognized by the ship inspection department must be held. 7.2 When inspecting by ultrasonic method, a qualification certificate for ship non-destructive testing (ultrasonic testing) personnel recognized by the ship inspection department must be held. 8 Nondestructive testing equipment
Nondestructive testing equipment and instruments must be calibrated by a legal metrology agency before use. 9 Nondestructive testing process and acceptance
9.1 Radiographic method shall be in accordance with CB/T3558.
9.2 Ultrasonic method shall be in accordance with CB/T3559.
10 Repair and re-inspection of unqualified welds
10.1 Repair and re-inspection of welds of ship hulls and their components10.1.1 Welds that are below the corresponding acceptance standards shall be repaired and re-inspected. 10.1.2 If welds that have been repaired twice are still unqualified after inspection, the manufacturer shall make further technical treatment in accordance with relevant regulations. 10.1.3 When hazardous defects (cracks, lack of fusion, lack of penetration) are found at one or both ends of the inspection area (section), an additional inspection area (section) shall be added in its extension direction. If the above-mentioned hazardous defects are still found in the welds of the additional inspection area (section), the entire weld shall be repaired and re-inspected. 10.2 The repair and re-inspection of welds of marine boilers, pressure vessels and their piping systems shall be carried out in accordance with the "Steel Seagoing Ship Classification Construction Rules" or "Inland Steel Ship Construction Rules".
11 One-time inspection pass rate
If the one-time pass rate of all shell plate end welds inspected is lower than 80% of the total number of inspection areas (sections), the manufacturer shall analyze the reasons and take measures (including re-inspection of welding procedures, etc.). 12 Confirmation and review of flaw detection results
12.1 For welds that are 100% inspected by radiography and ultrasonic methods, if one of the methods is confirmed to be unqualified in the same inspection area (section), it shall be treated as unqualified.
12.2 Welds that are inspected by one method generally do not need to be reviewed by another method. 12.3 If the surveyor raises doubts about the ultrasonic flaw detection results, the surveyor shall select some welds for joint inspection with the flaw detection personnel. 13 Documents and reports
The manufacturer shall submit the following flaw detection documents and reports to the surveyor. 13.1 A detailed list of the locations of each inspection area (section) and indicate the flaw detection method. 3
CB/T3177-94
13.2 The total length of the inspected welds, the total number of inspection areas (sections), the qualified rate, the repaired locations and the number of times. 13.3 Flaw detection report and summary table.
The formats of the flaw detection report and summary table are shown in Appendix A (reference) and Appendix B (reference) respectively. Product name and number
Non-destructive testing record number
Weld number
Signature of the evaluator:
Project number
Non-destructive testing report number
Total number of detection sections
Manufacturer's quality inspection department supervisor
Surveyor's signature
Non-destructive testing methods and standards
CB/T 3177-94
Appendix AbzxZ.net
Non-destructive testing report
(reference part)
Section or part number
Acceptance level
Detection section length, mm
Date:
Non-destructive testing method
Signature of report reviewer:
Appendix B
Summary table
(reference part)
Defect status
Date:
Product name||tt| |Number of detection sections
First pass rate
Supervisor of non-destructive testing room
Evaluation results
First repair
Report number:
Evaluation results
Second repair
4 Inspection quantity
CB/T3177-94
4.1 Ocean transport ship
4.1.1 The number of radiographs (number of inspection sections) N of the strength deck and shell within 0.6L of the swelling part shall be calculated according to formula (1). The inspection of butt welds in other parts shall be agreed upon by the manufacturer and the surveyor, and generally not more than 0.1N. N=0.25(i+0.1W+0.1W,)
Where: N
Number of films;
Total number of intersections of longitudinal and transverse butt welds within the 0.6L range of the touch part; Total length of transverse butt welds within the 0.6L range of the touch part, m; Total length of longitudinal butt welds closed in sections within the 0.61 range of the swelling part, m. The inspection quantity of the butt welds of independent tanks and cabinets of liquefied natural gas and petroleum gas carriers is 100%. The inspection quantity of welds of other dangerous chemical carriers shall be determined by the "Rules for the Construction of Steel Seagoing Ships". The inspection quantity of welds of boilers, pressure vessels and pressure piping systems of all levels of ships shall be determined in accordance with the "Rules for the Construction of Steel Seagoing Ships". 4.2 The inspection basis of shell plate welds within the 0.4L area of ​​marine fishing vessels
is calculated according to formula (2). Ny=0.21
Wherein: Ny-
Weld inspection volume, m;
The total number of intersections of longitudinal and transverse butt welds in the 0.4L area of ​​the swelling part. 4.2.2 The inspection quantity of the large closed transverse butt weld is calculated according to formula (3). T=0.05W
Where: T——
Weld inspection, m
W—Total length of the large closed butt weld, m.
（1）
（3）
4.2.3 Except for Articles 4.2.1 and 4.2.2, the inspection quantity of butt welds in other parts shall be agreed upon by the manufacturer and the fishery inspection department, and shall generally not exceed 0.2~0.3Ny.
4.2.4 The inspection quantity of welds of boilers, pressure vessels and pressure piping systems of all levels of ships shall be in accordance with Article 4.1.4. 4.3 River transport ships
4.3.1 The inspection quantity of large closed transverse butt welds is: when L≥65m, it is calculated according to formula (4); when L<65m, it is calculated according to formula (5).
Na=0.05Wa
Na=0.03Wa
Where: Nd inspection quantity.m;
Wa--total length of large closure transverse butt weld, m. 4.3.2 The inspection quantity of shell transverse butt welds in the 0.4L area (except large closure welding) is calculated according to formula (6). N,=0.02W
Where: N; inspection quantity, m;
·（4）
.（5）
（6）
W--total length of shell transverse butt welds in the 0.4L area of ​​the swelling part, m. 4.3.3 Except for 4.3.1 and 4.3.2, the inspection quantity of butt welds in other parts shall be agreed upon by the manufacturer and the surveyor, and shall generally not exceed 0.2N;. 4.3.4 The hull welds (except large joint welds) of ships less than 30m in length may be exempted from inspection with the consent of the ship's experiencer. 4.3.5 The inspection quantity of welds of boilers, pressure vessels and pressure piping systems of all levels of ships shall be determined in accordance with the "Rules for the Construction of Inland Steel Ships". 5 Inspection area (section)
1 When the inspected welds are inspected by radiography, the length of each inspection area (section) is 300mm; and the weld inspection shall be carried out by the surveyor or the manufacturer. 5.1
Additional instructions:
CB/T3177
This standard was proposed by the Technical Committee of the National Technical Committee for Standardization of Marine Ships, and this standard was proposed by the Seventh Research Institute of China State Shipbuilding Corporation, the Tenth Institute of the Seventh Research Institute of China State Shipbuilding Corporation. This standard was drafted by Gu Shiyao,
Published by China Standards Press Printed by Qinhuangdao Printing Factory of China Standards Press First edition in January 1995 First printing in January 1995 Book number: 155066·2-9601
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