GOST R ISO 10893-6-2016
GOST R ISO 10893−6-2016 seamless steel Tubes and welded. Part 6. Radiographic testing of welds for detection of defects
GOST R ISO 10893−6-2016
NATIONAL STANDARD OF THE RUSSIAN FEDERATION
Seamless steel tubes and welded
Part 6
Radiographic testing of welds for detection of defects
Seamless and welded steel tubes. Part 6. Weld seam radiographic testing for the detection of imperfections
OKS 23.040.10
77.040.20
77.140.75
Date of introduction 2016−11−01
Preface
1 PREPARED by the Technical Committee for standardization TC 357 «Steel and cast iron pipes and cylinders», non-state educational institution of additional professional education, Scientific-training center «testing and diagnostics» (RTC «testing and diagnostics») and Open joint stock company «Russian scientific research Institute of pipe industry» (JSC «RosNITI») on the basis of their own translation into the Russian language the English language version of the standard specified in paragraph 4
2 SUBMITTED by the Technical Committee for standardization TC 357 «Steel and cast iron pipes and cylinders»
3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology of April 1, 2016 N 236-St
4 this standard is identical to international standard ISO 10893−6:2011* «non-destructive testing of steel tubes. Part 6. Radiographic testing of the weld of welded steel tubes for detection of defects» («Non-destructive testing of steel tubes — Part 6: Radiographic testing of the weld seam of welded steel tubes for the detection of imperfections», IDT).
An international standard developed by ISO Technical Committee ISO/TC 17 «Steel», Subcommittee SC 19 «Technical delivery conditions for pipes working under pressure».
The name of this standard changed with respect to names specified international standard to link with the names adopted in the current national set of standards.
In applying this standard it is recommended to use instead of the referenced international standards corresponding national standards of the Russian Federation, details of which are given in Appendix YES
5 INTRODUCED FOR THE FIRST TIME
Application rules of this standard are established in GOST R 1.0−2012 (section 8). Information about the changes to this standard is published in the annual (as of January 1 of the current year) reference index «National standards», and the text changes and amendments — in monthly information index «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in the monthly index «National standards».
Introduction
In the complex of ISO 10893 under the name «non-destructive testing of steel tubes» includes:
— part 1. Automatic electromagnetic inspection of steel seamless and welded tubes (except tubes produced by arc welding under flux) for verification of the tightness;
— part 2. Automatic inspection eddy current seamless and welded steel pipes (excluding pipes obtained by arc welding under flux) for detection of defects;
— part 3. Automatic control method of magnetic flux leakage around the entire circumference of seamless and welded pipes made of ferromagnetic steel (except tubes produced by arc welding under flux) for the detection of longitudinal and/or transverse defects;
— part 4. The control method of penetrating liquids seamless and welded steel tubes for the detection of surface defects;
— part 5. Control method of magnetic particles seamless and welded pipes made of ferromagnetic steel for detecting surface defects;
— part 6. Radiographic testing of the weld of welded steel tubes for detection of defects;
— part 7. Digital radiographic testing of the weld of welded steel tubes for detection of defects;
— part 8. Automatic ultrasonic testing of seamless and welded steel tubes for the detection of laminations;
— part 9. Automatic ultrasonic testing for the detection of laminations in the strip/sheet metal used to manufacture welded steel pipes;
— part 10. Automatic ultrasonic testing along the whole circumference of seamless and welded steel pipes (excluding pipes obtained by arc welding under flux) for the detection of longitudinal and/or transverse defects;
— part 11. Automatic ultrasonic testing of the weld of welded steel tubes for the detection of longitudinal and/or transverse defects;
— part 12. Automatic ultrasonic control of thickness around the circumference of seamless and welded steel pipes (excluding pipes obtained by arc welding under flux).
1 Scope
This standard specifies requirements for x-ray testing x-rays with film longitudinal or spiral weld steel pipe, automatic arc fusion welding, for detection of defects.
This standard can be applied for control of closed hollow profiles.
Note — a Possible alternative is the application of digital radiographic inspection in accordance with ISO 10893−7.
2 Normative references
For the application of this standard requires the following referenced documents are*. For undated references, use the latest edition of the referenced document, including all changes:
ISO 5576 nondestructive testing. Industrial radiology using x-rays and gamma rays. Dictionary. (ISO 5576 Non-destructive testing — Industrial X-ray and gamma-ray radiology — Vocabulary)
ISO 5579 non-destructive Control. Radiographic testing of metallic materials using x-rays and gamma rays. Basic rules. (ISO 5579 Non-destructive testing — Radiographic testing of metallic materials using film and X — or gamma rays — Basic rules)
ISO 9712 nondestructive testing. Qualification and certification of personnel (ISO 9712 Non-destructive testing — Qualification and certification of NDT personnel)
ISO 10893−7 non-destructive testing of steel tubes. Part 7. Digital radiographic testing of the weld of welded steel tubes for the detection of defects. (ISO 10893−7 Non-destructive testing of steel tubes — Part 7: Digital radiographic testing of the weld seam of welded steel tubes for the detection of imperfections)
ISO 11484 steel Products. The system of training for the employer personnel for non-destructive testing* (ISO 11484 Steel products — Employer''s qualification system for nondestructive testing (NDT) personnel)
ISO 11699−1 non-destructive Control. X-ray films for industrial radiography. Part 1. Classification of film systems for industrial radiography. (ISO 11699−1 Non-destructive testing — Industrial radiographic film — Part 1: Classification of film systems for industrial radiography)
ISO 17636 non-destructive Control of the welded joints. Radiographic testing of welded joints obtained fusion. (ISO 17636 Non-destructive testing of welds — Radiographic testing of fusion-welded joints)
__________________ISO 17636 replaced by ISO 17636−1 «testing of welded joints non-destructive. Radiographic control. Part 1. Methods of x-ray and gamma radiation using the film».
ISO 19232−1 nondestructive testing. Image quality in x-ray images. Part 1. Determining values of image quality using indicators of the quality of the image of wire type. (ISO 19232−1 Non-destructive testing — Image quality of radiographs — Part 1: Determination of the image quality value using wire-type image quality indicators)
ISO 19232−2 nondestructive testing. Image quality in x-ray images. Part 2. Determining values of image quality using indicators of the quality of the image type, step/hole. (ISO 19232−2 Non-destructive testing — Image quality of radiographs — Part 2: Determination of the image quality value using step/hole-type image quality indicators)
3 Terms and definitions
This standard applies the terminology of ISO 5577 and ISO 11484 and the following terms with respective definitions:
3.1 pipe (tube) Hollow long product, open at both ends, of any shape in cross section.
3.2 welded tube (welded tube): Pipe manufactured by forming a hollow profile from a flat product and welding adjacent edges together, which after welding can be further processed (hot or cold) to its final dimensions.
3.3 the manufacturer (manufacturer): Organization that manufactures products in accordance with the relevant standards and States the conformity of the delivered products with all applicable provisions of the relevant standard.
3.4 agreement (agreement): a Contractual relationship between the manufacturer and the customer at the time of enquiry and order.
4 General requirements
4.1 If the specification for the products or the agreement between the customer and the manufacturer do not stipulate otherwise, the radiographic examination should be carried out on tubes after completion of all primary technological operations of production (rolling, heat treatment, cold and hot deformation, processing size, pre-edits, etc.).
4.2 Control should be carried out only by trained operators, qualified in accordance with ISO 9712, ISO 11484 or equivalent documents related to and under the supervision of competent personnel appointed by the manufacturer (the manufacturer). In case of inspection by a third party this must be agreed between the purchaser and the manufacturer. Control by permission of the employer must be conducted in accordance with written procedure. The procedure of nondestructive testing must be coordinated by a specialist 3 level, and personally approved by the employer.
Note — the Definition of levels 1, 2 and 3 to watch in relevant international standards, e.g. ISO 9712 and ISO 11484.
4.3 Pipe must be sufficiently straight to ensure the possibility of control. The surface of the weld and adjacent base metal shall be free from foreign matter and irregularities, which can affect the correct interpretation of radiographic images.
Allowed the grinding surface to achieve acceptable surface quality.
4.4 deleting a strengthening of the weld markers (usually lead arrows) should be located in every area of the seam so that it was possible to identify its position on the radiographic image.
4.5 Symbols for identification, usually in the form of lead letters, should be placed in each area dispatches, so that image data of symbols appear on each radiograph to ensure unequivocal identification of the site.
4.6 the Surface of the pipe from the source of radiation should be provided with permanent markings to provide reference points to determine the exact situation of each radiogram. If the characteristics of the product or the anticipated operating conditions are such that the application of the marking is impossible, shall be provided other appropriate means to bind the messages to the reference system, for example, marking by means of paint or the link to the sketch with the exact location of the telegrams.
4.7 When carrying out radiography of weld seam of great length with some of the films adjacent the film should be superimposed on each other with an overlap of at least 10 mm to ensure that no section of the length of the weld is controlled.
5 control Technology
5.1 Longitudinal or spiral weld of the pipe should be controlled by method for radiographic inspection x-ray radiation using the film. Digital radiographic inspection without film is carried out according to ISO 10893−7.
5.2 In accordance with ISO 17636 shall be equipped with two-class image quality:
class a: method of radiographic inspection standard sensitivity;
class B: a method of radiographic inspection c improved sensitivity.
Note — For most products is enough use of the image quality class A. Image quality class B is a more responsible and complex products, when the image quality class A may be insufficiently sensitive to identify all discoverable defects. For image quality class B requires the use of film systems grade C4 or above (fine-grained film with lead screens), and, accordingly, they require a longer exposure time. Required class image quality must be set to the appropriate specifications for the products.
5.3 the Applied film system class must be at least C5 for image quality class A and C4 (C3 to voltage x-ray tube of less than 150 kV) for image quality class B (classes of film systems installed in ISO 5579, ISO 11699−1 and ISO 17636).
The front reinforcing metal screen for image quality class A and for image quality class B must be with a thickness of from 0.02 to 0.25 mm. Other thickness can be set for the rear intensifying screen. When using the method of two films, both the intensifying screen should be in the thickness range specified for the front intensifying screen.
5.4 Salt intensifying screens should not be applied.
5.5 Dose back-scattered, and internal scattered x-ray radiation absorbed by the film, should be minimized.
If in doubt, protection from back-scattered x-ray radiation symbol (usually a lead letter «B» with a height of 10 mm and a thickness of 1.5 mm) should be attached to the back side of the cassette or holder of the film, and then the normal way it is necessary to make a radiogram. If the telegram you receive this symbol of lower density than the surrounding background, which means that protection against back scattered radiation is insufficient and it is necessary to take additional measures of protection.
5.6 the Central axis of the beam of radiation should be directed to the center of the controlled area of the weld perpendicular to the surface of the pipe at this point.
5.7 the Length of one exposure area should be such that the difference in the illuminated thicknesses at the ends of informative site radiograms does not exceed the thickness of the illuminated in its center by more than 10% for image quality class and more than 20% for image quality class And, provided that you meet the requirements set out in 5.11 and section 8.
5.8 you Should use the method of x-raying through one wall. If this method cannot be applied on geometrical considerations, by agreement between the manufacturer and the customer allowed the use of the method of scanning through two walls.
5.9 the gap between the film and the surface of the weld must be minimal.
5.10 the Minimum value of the distance f from the radiation source to the object of control should be chosen so that the ratio of the distance to an effective focal spot size d, i.e.f/d, consistent with the values given by the following formulas:
for image quality class A:
for image quality class B:
where b is the distance between the surface of the weld from the radiation source and the sensitive surface of the film (including the gap between the film and the test object).
Note — this relationship is Graphically presented in figure 1.
Figure 1 — Nomogram for determining the minimum distance from the source to the weld f against the distance from the weld surface from the radiation source to the film b and the effective focal spot size d
_________________Effective focal spot size, d, mm.
The minimum distance from the source to the weld f for the class quality.
The minimum distance from the source to the weld f for the quality class A, mm.
The distance between the surface of the weld from the radiation source and the sensitive surface of the detector b, mm.
Figure 1 — Nomogram for determining the minimum distance from the source to the weld f against the distance from the weld surface from the radiation source to the film b and the effective focal spot size d
5.11 Conditions of exposure must be such that the optical density of radiographic images of weld metal without defects in a controlled region was not less than 2.3 for image quality class B and not less than 2.0 for image quality class A. fog Density should not exceed 0.3. Fog density is defined as the total density (emulsion and base) of a processed, unexposed film.
5.12 To maintain sufficient sensitivity of the x-ray tube voltage must not exceed the maximum values (see figure 2).
Figure 2 — Maximum voltage at the x-ray tube for units with a capacity of up to 500 kV as a function of the thickness being radiographed
X — illuminated thickness, mm; Y — voltage x-ray tube, kV
Figure 2 — Maximum voltage at the x-ray tube for units with a capacity of up to 500 kV as a function of the thickness being radiographed
