GB/T 3323.1-2019 PDF English
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Non-destructive testing of welds -- Radiographic testing -- Part 1: X-and gamma-ray techniques with film
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| GB/T 3323-2005 | English | 150 |
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Radiographic examination of fusion welded joints in metallic materials
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| GB/T 3323-1987 | English | 839 |
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Methods for radiographic inspection and classification of radiographs for fusion welded butt joints in steel
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PDF Preview: GB/T 3323.1-2019
GB/T 3323.1-2019: PDF in English (GBT 3323.1-2019) GB/T 3323.1-2019
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 25.160.40
J 33
Replacing GB/T 3323-2005
Non-destructive testing of welds - Radiographic
testing - Part 1: X-and gamma-ray techniques with film
(ISO 17636-1:2013, MOD)
ISSUED ON: AUGUST 30, 2019
IMPLEMENTED ON: MARCH 01, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 6
2 Normative references ... 6
3 Terms and definitions ... 7
4 Symbols and abbreviations ... 9
5 Grading of radiographic testing technology ... 9
6 General rules ... 10
7 Recommended radiographic testing technology ... 13
8 Test report ... 29
Appendix A (Normative) Minimum image quality value ... 31
Appendix B (Normative) Recommended number of exposures for 100%
radiographic testing of butt girth welds ... 34
Non-destructive testing of welds - Radiographic
testing - Part 1: X-and gamma-ray techniques with film
1 Scope
This part of GB/T 3323 specifies the radiographic testing technology for fusion
welding of metallic materials.
This part applies to radiographic testing of welded joints of plates, pipes or other
welded joints.
This part does not include the acceptance level of radiographic testing of
welded joints of metallic materials.
If the parties to the contract use testing conditions, which are lower than this
part, the quality of the testing images is very likely to drop significantly.
Note: This part meets the requirements of GB/T 19943. The detector used is film.
2 Normative references
The following documents are essential to the application of this document. For
the dated documents, only the versions with the dates indicated are applicable
to this document; for the undated documents, only the latest version (including
all the amendments) is applicable to this standard.
GB/T 9445 Non-destructive testing - Qualification and certification of NDT
personnel (GB/T 9445-2015, ISO 9712:2012, IDT)
GB/T 12604.2 Non-destructive testing - Terminology - Terms used in
radiographic testing (GB/T 12604.2-2005, ISO 5576:1997, IDT)
GB/T 19348.1 Non-destructive testing - Industrial radiographic film - Part 1:
Classification of film systems for industrial radiography (GB/T 19348.1-2014,
ISO 11699-1:2008, MOD)
GB/T 19348.2 Non-destructive testing - Industrial radiographic films - Part 2:
Control of film processing by means of reference values (GB/T 19348.2-
2003, ISO 11699-2:1998, IDT)
GB/T 19802 Non-destructive testing - Industrial radiographic illuminators -
Minimum requirements (GB/T 19802-2005, ISO 5580:1985, IDT)
GB/T 19943 Non-destructive test - Radiographic examination of metallic
materials by X-and gamma-rays - Basic rules (GB/T 19943-2005, ISO
5579:1998, IDT)
GB/T 23901.1 Non-destructive testing - Image quality of radiographs - Part
1: Determination of the image quality value using wire-type image quality
indicators (GB/T 23901.1-2019, ISO 19232-1:2013, IDT)
GB/T 23901.2 Non-destructive testing - Image quality of radiographs - Part
2: Determination of the image quality value using step/hole-type image
quality indicators (GB/T 23901.2-2019, ISO 19232-2:2013, IDT)
GB/T 23901.4 Non-destructive testing - Image quality of radiographs - Part
4: Experimental evaluation of image quality values and image quality tables
(GB/T 23901.4-2019, ISO 19232-4:2013, IDT)
GB/T 25758 (all parts) Non-destructive testing - Focus characteristics of
industrial X-ray system
EN 12679 Non-destructive testing - Radiographic testing -Determination of
the size of industrial radiographic gamma sources
3 Terms and definitions
The terms and definitions as defined in GB/T 12604.2, as well as the following
terms and definitions, apply to this document.
3.1
Nominal thickness
The nominal thickness of the base metal, which does not consider the
manufacturing deviation.
3.2
Penetrated thickness
The thickness of the material, in the direction of ray transmission, which is
determined by the nominal thickness of the material.
to technical or structural reasons (such as the type of radiation source, the
source-to-object distance, etc.), as agreed by the parties to the contract, it may
select the penetration conditions, which is specified in the grade A technology.
At this time, the loss of sensitivity can be compensated, by increasing the
minimum blackness of the negative to 3.0 OR selecting a higher level of film
system, which has a minimum blackness of 2.6; however, the other conditions
specified in the grade B shall remain unchanged, especially the image quality
to achieve (see Table A.1 ~ Table A.12 in Appendix A). Since the sensitivity,
after compensation, is better than the grade A technology, it can be considered
that the workpiece is penetrated, according to the grade B technology. For the
penetration layout of 7.1.4 and 7.1.5, if the source-to-film distance is reduced,
according to 7.6, there is no need to perform sensitivity compensation,
according to the above method.
6 General rules
6.1 Radiation safety protection
If it is lack of proper protection measures, X or gamma rays may cause serious
harm to human health. The use of X-ray equipment or radioactive sources shall
comply with the requirements of laws and regulations on radiation protection.
When carrying out radiographic testing work, it shall strictly implement the
safety protection measures, which are stipulated by relevant laws and
regulations.
6.2 Surface treatment and testing timing
The surface of the workpiece usually does not need to be treated. However,
when the surface defect or the coating affects the detection of the defect, the
surface of the workpiece shall be polished OR the coating shall be removed.
Unless otherwise specified, radiographic testing shall be carried out after
manufacturing, such as after grinding or heat treatment.
6.3 Positioning of welds on radiographic film
When the boundary of the weld cannot be clearly displayed, on the radiographic
film, it shall place the positioning marks of high-density materials, on both sides
of the weld.
6.4 Marking of radiographic film
For each penetration segments of the tested workpiece, it shall place the
identification mark, which is composed of letters, numbers, symbols, such as:
product number, weld number, repair mark, penetration date, etc., to represent
the information of the workpiece and location to which the tested image belongs.
The marked image shall be located outside the effective evaluation area;
meanwhile it shall ensure that each segment is clearly and correctly marked.
6.5 Marking of workpiece
The surface of the workpiece should be permanently marked, to ensure the
accurate positioning of each film (for example: zero point, direction, marking,
size, etc.).
If the nature of the material or the conditions of use do not allow permanent
marking on the surface of the workpiece, it can be recorded, by means of
penetration diagrams or photographs.
6.6 Film overlap
When more than two films are used, to detect the penetration area, each film
shall have a certain overlap area, to ensure that the entire tested area is
penetrated. The high-density lap mark shall be placed on the surface of the
workpiece in the lap area, meanwhile it can be displayed on each radiographic
film.
6.7 Minimum image quality value
The minimum image quality requirements for radiographic testing of metal
material welds are as shown in Table A.1 ~ Table A.12. The image quality
requirements, for radiographic testing of other materials, shall be determined
by the parties to the contract, in accordance with the provisions of GB/T 23901.4.
When Ir192 or Se75 is used for testing, if the image quality value cannot meet
the requirements of Table A.1 ~ Table A.12, the following requirements can be
implemented, as agreed by the parties to the contract:
Double-wall double-shadow penetration technology, grade A and grade B (w =
2t):
- Use Ir192, 10 mm < w ≤ 25 mm, which allows image quality value minus 1;
- Use Se75, 5 mm < w ≤ 12 mm, which allows image quality value minus 1.
Single-wall single-shadow and double-wall single-shadow penetration
technology, grade A:
- Use Ir192, 10 mm < w ≤ 24 mm, which allows image quality value minus 2;
- Use Ir192, 24 mm < w ≤ 30 mm, which allows image quality value minus 1;
- Use Se75, 5 mm < w ≤ 24 mm, which allows image quality value minus 1.
When the image quality indicator is placed on the side of the film, the type "F"
shall be placed, close to the image quality indicator. Meanwhile, it shall be
indicated in the test report.
If relevant measures are taken to ensure that, the same penetration part of the
tested workpiece or area is ray detected, by the same penetration parameters
and penetration technology, meanwhile there is no difference in the contrast
sensitivity of the obtained images, it is not necessary to determine the contrast
sensitivity of each image. For the determination of specific image's contrast
sensitivity, the requirements should be negotiated by the parties to the contract.
For pipe butt welds, which have an outer diameter greater than or equal to 200
mm, when using the ray source center method for circumferential penetration,
it should place at least three image quality indicators, at equal intervals, in the
circumferential direction.
6.9 Evaluation of image quality
The observation conditions of the film shall meet the requirements of GB/T
19802.
By observing the image of the image quality indicator on the film, determine the
number of the thinnest identifiable wire diameter OR the number of the smallest
aperture, as the image quality value. For the wire type image quality indicator,
if there is at least 10 mm of wire length, which is continuously and clearly visible,
in the uniform blackness area, the wire is considered to be identifiable. For the
stepped hole type image quality indicator, if there are two holes having the same
diameter on the step, then both holes shall be identifiable; and the step is
considered identifiable.
In the radiographic testing report, it shall indicate the type and model of the
image quality indicator used AND the achieved image quality value.
6.10 Personnel qualifications
The personnel who carry out radiographic testing, according to this part, shall
be qualified and certified, in accordance with GB/T 9445 OR agreed by the
parties to the contract; obtain the qualification level certificate of the relevant
industrial category of radiographic testing. The employer or its agent shall
provide professional training and authorization for them.
7 Recommended radiographic testing technology
7.1 Penetration method
7.1.1 General
Under normal circumstances, the weld's radiographic testing technology shall
be implemented, in accordance with the provisions of Figure 1 ~ Figure 19.
The film shall be placed as close to the tested workpiece as possible.
If De is greater than 100 mm, OR t is greater than 8 mm, OR the pipe butt girth
weld which has a width of greater than De/4, it should not use the double-wall
double-shadow elliptical penetration technique of Figure 11. When the double-
wall double-shadow ellipse penetration is used, if t/De is less than 0.12, it will
be penetrated twice at a 90° interval; if the conditions are not met, it will be
penetrated three times at a 120° or 60° interval. The maximum distance
between the elliptical images shall be approximately one weld width.
For pipe butt girth weld, which has an outer diameter De less than or equal to
100 mm, if it is difficult to use the double-wall double-shadow ellipse penetration,
it may use the vertical penetration technology (see Figure 12), to penetrate 3
times, at 120° or 60° intervals, according to 7.1.7.
When using the penetration layout of Figure 11, Figure 13, Figure 14, the
incident angle of the ray beam shall be as small as possible; however, it shall
prevent the overlap of the upper and lower weld images. Under the premise of
meeting 7.6, when using the penetration layout of Figure 13, f shall be as small
as possible. The image quality indicator and type "F" shall be placed close to
the film.
Due to the difference in the geometry of the workpiece or the thickness of the
material, through negotiation by the parties to the contract, it may use other
penetration technologies. One of the methods is given in 7.1.9. For workpieces,
which have uniform cross-sectional thickness, the multi-film method shall not
be used, to reduce the exposure time. In addition, the same material can be
used for thickness compensation.
Note: See Appendix B, for the number of exposures, which is required for 100%
penetration of butt girth welds.
7.1.2 Single-wall penetration method
The ray source is on one side of the tested workpiece; the film is on the other
side, as shown in Figure 1.
The darkroom processing of the film is carried out, in accordance with the
conditions recommended by the film and chemical manufacturers, to obtain the
performance of the selected film system. Particular attention shall be paid to
temperature, development time, developing time. Film processing shall be
checked regularly, according to GB/T 19348.2. The radiographic film should not
be falsely displayed, on the radiographic negative, due to defects in the film's
manufacturing, processing, exposure or darkroom processing.
7.10 Film evaluation conditions
The evaluation of the negative shall be carried out in a dimly lit room. The
brightness of the image viewer shall be adjustable. The light screen should have
a shading plate, to block the non-evaluation area. The film viewer shall meet
the requirements of GB/T 19802.
8 Test report
After the radiographic testing, it shall record the test results and related test
parameters in detail; fill the test report, so that the test results can be inquired,
under any circumstances.
The test report shall contain at least the following information:
a) Testing organization;
b) The name of the workpiece;
c) Material;
d) Heat treatment status;
e) The groove form of the weld;
f) Nominal thickness;
g) Welding method;
h) Testing standards, including acceptance requirements;
i) Radiographic testing technology and grade, including image quality
indicators and required image quality values;
j) Penetration layout;
k) Marking;
l) Layout picture;
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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