GOST R ISO 10124-99

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  ГОСТ Р ИСО 10124-99

GOST R ISO 10124−99 pressure steel Tubes seamless and welded (except pipe manufactured by arc welding under flux). Ultrasonic testing method of delamination

GOST R ISO 10124−99

Group В69

STATE STANDARD OF THE RUSSIAN FEDERATION

OF STEEL PIPE PRESSURE SEAMLESS AND WELDED (EXCEPT PIPE MANUFACTURED BY ARC WELDING UNDER FLUX)

Ultrasonic testing method of delamination

Seamless and welded (except submerged AGS-welded) steel tubes for pressure purposes. Ultrasonic testing for the detection of laminar imperfections

OKS 19.100
AXTU 0009

Date of introduction 2001−01−01

Preface

1 DEVELOPED AND SUBMITTED by the Technical Committee for standardization TC 132 «Technical diagnostics"

2 ADOPTED AND put INTO EFFECT by the Resolution of Gosstandart of Russia from December 23, 1999 No. 672-St

3 this standard is the authentic text of international standard ISO 10124−94* «steel pressure Pipe seamless and welded (except pipe manufactured by arc welding under flux). Ultrasonic testing method of fibre bundles"
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* Access to international and foreign documents referred to here and hereinafter, can be obtained by clicking on the link to the site shop.cntd.ru. — Note the manufacturer’s database.

4 INTRODUCED FOR THE FIRST TIME

5 REISSUE

Introduction

This standard applies to the ultrasonic testing method seamless and welded steel pipes (except pipes, made by arc welding under flux) for detection of laminations.

The term «lamination defect» means any defect that is located generally parallel to the surface of the pipe within the thickness of the product.

Discusses four different acceptance levels (table 1). The choice between these levels relates to the competence of the ISO Technical Committee responsible for developing the relevant standards.

1 Scope

1.1 this standard specifies requirements for the ultrasonic method of testing of seamless and welded steel pipes (excluding pipes, made by arc welding under flux) for detection of laminations in accordance with the four acceptance levels of control. Acceptance level B1 only applies to seamless tubes intended for use in critical conditions, such as parosbornoj (table 1).

Note — For welded pipe (excluding pipes made arc submerged arc welding) requirements for the ultrasonic testing for detection of laminations are defined in the international standard ISO 12094. In this case, the ultrasonic inspection is carried out on steel strips, which must be manufactured tubes.

1.2 this standard applies to pipe of an external diameter exceeding 30 mm. the Lower limit of wall thickness is not set.

Note — there may be difficulties in applying this control method to detect laminations and to classify them according to size thickness of pipe wall less than 5 mm. In such cases, coordination is required between consumer and manufacturer methods for the inspection of pipes and sizes classification of defects.

2 Normative references

The present standard features references to the following standard:

ISO 12094−94* welded steel Pipes-pressure. Ultrasonic inspection to determine delamination in strip (sheet) material, used for manufacturing welded pipes
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* International standard in VNIIKI of Gosstandart of Russia.

3 General requirements

3.1 Ultrasonic inspection regulated by this standard usually carried out on tubes after completion of all manufacturing operations.

Monitoring should be conducted by personnel certified (certificated) in accordance with a valid certification and is assigned by the manufacturer.

In the case of control by a third party this must be agreed between customer and manufacturer.

3.2 Curvature of the pipe and the condition of the surface must meet the requirements of the applicable instruments ultrasonic testing.

4 Method of control

4.1 the testing of tubes for defects stratification using acompulsory method for ultrasonic testing by sending pulses of ultrasonic oscillations in the product perpendicular to its surface.

4.2 During the test, the pipe and (or) ultrasonic transducer must move relative to each other with a step scan allows the detection of defects of delamination size, not less than given in table 1.


Table 1 — Acceptance levels and their corresponding dimensions of laminations, which are found in pipes with ultrasonic testing

Note — At both ends of the pipe can be short segments that are not subject to control. In this case, the manufacturer needs to cut them or to carry out manual ultrasonic inspection, using the appropriate acceptance levels.

4.3 the Maximum size of each of the applied ultrasonic transducer, measured parallel to the axis of the tube should not be more than 30 mm. Minimum frequency of ultrasonic probe should be 2 MHz (nominal).

4.4 Ultrasonic unit must ensure that grading of pipes (good and bad) through automatic operation at set value rejection level combined with a marking system and (or) sort.

5 Standard samples

5.1 Standard patterns defined in this standard, are the standards, suitable for calibration of nondestructive testing equipment. The sizes of artificial reflectors in these standards should not be considered as the minimum defect size detectable by the equipment.

5.2 Ultrasonic equipment is calibrated electronically using smooth tubular specimens according to standard 7.1.1 or using standard samples with flat bottomed holes, square or rectangular excavation (figure 1), carved on the inner surface of the tubular test sample, given the fact that the acceptance level B1 you can use the benchmarks only with flat bottomed holes.

Figure 1 — forms of reference holes and recesses

 — the length of the rectangular recess (the only limitation 6 mm);  — width of the rectangular recess and the diameter of the hole; the depth of the rectangular recesses and openings;  — the wall thickness of the pipe

Figure 1 — forms of reference holes and recesses

A standard sample with flat-bottomed hole is used as the primary means to establish the sensitivity of the test equipment. When using other types of standard samples the sensitivity is adjusted so that it was equivalent to the sensitivity obtained when using a sample with flat-bottomed hole.

5.3 Standard sample should have the same nominal diameter, thickness and surface finish as the tube to be controlled, as well as similar acoustic properties.

6 Sizes of artificial reflectors in the standard samples

6.1 Artificial reflectors are used in the standard samples should have the following dimensions.

6.1.1 the Width (transverse dimension) — (6+10%) mm.

6.1.2 Depth of the recesses is in the range from the nominal thickness of the pipe at maximum 10 mm.

6.2 the Size and shape of a standard sample must be tested out in the appropriate way.

7 Calibration and control of test equipment

7.1 Test equipment is calibrated in a static state with the use of electronic means in accordance with 7.1.1 or 7.1.2 according to standard samples.

By agreement between the consumer and the manufacturer of the test equipment can also be calibrated in a dynamic state, which ensures that for the selected step control and the pulse repetition frequency the equipment will detect the bundle with minimum dimensions (), listed in table 1.

7.1.1 Calibration with use of electronic means

The reference level is the level 10 dB less than the amplitude of the first backwall echo signal at the ultrasonic transducer on the smooth tubular standard sample.

Necessary, the sensitivity adjustment needs to be made before the start of production control, the manufacturer must ensure the ability of a device to detect the reference hole or notch if you set the sensitivity.

7.1.2 Calibration using standard sample

The reference level is the amplitude level of the first echo signal when the ultrasonic transducer is fixedly over the center of the reference holes or recesses.

7.2 During the production testing of tubes the speed of relative rotation and (or) displacement, and the pulse repetition frequency must be selected in order to detect stratification with a minimum size of () and circular () in accordance with table 1 based on the rejection level.

7.3 verification of the calibration should be carried out at regular intervals during the production testing of tubes of the same gauge using the selected standard sample. The frequency of calibration verification must be at least 4 h or once every 10 pipes is controlled regardless of the length control. In addition, the calibrations need to be done always when there is a change of brigade operators serving equipment, and at the beginning and end of the production cycle.

Note — In cases where production control is carried out during an entire work shift, a 4-hour period may be extended by agreement between the consumer and manufacturer.

7.4 the Equipment shall be re-calibrated after any adjustments to the system or in cases where there is a change in the mix of controlled pipes.

7.5 If after checking the calibration the calibration requirements are not satisfied even after increasing the sensitivity by 3 dB corrected for drift of the system, all pipes inspected since the previous calibration must be re-inspected after the re-calibration of equipment.

Repeated monitoring is not required even after dropping the sensitivity by more than 3 dB from the previous calibration with the appropriate recording, providing the grading of the pipes fit defective.

8 Acceptance

8.1 Any pipe, its characteristics are not exceeding the acceptance level, it is considered the last control.

8.2 Any pipe, its characteristics are exceed the acceptance level, it is considered defective or at the request of the manufacturer can be controlled again.

8.3 If the re-monitoring the acceptance level is not exceeded, the tube is considered the last control. When exceeding the rejection level, the pipe is considered defective.

8.4 For defective pipes should be taken one or more of the following measures in accordance with the requirements of the standard for products:

— questionable area you need to explore the manual method of ultrasonic inspection or by using a suitable automatic or semiautomatic system to establish the extent of phase separation. The pipe will be considered valid if the square of the separation () and the total area of the bundle do not exceed the values specified in table 2;

— questionable plot to be cut out. The manufacturer must guarantee to the consumer that all questionable areas are removed.

Otherwise, the pipe fail inspection.


Table — 2 Acceptance standards

9 test report

After the inspection, the manufacturer shall submit consumer test report which as a minimum includes the following information:

— reference to this standard;

— the date of the inspection;

— the acceptance level;

— official document about the quality of the pipe, held the control;

— the gauge tube and the batch number;

— the composition and the type of used equipment;

— description of the standard sample;

— the applied calibration method.