GOST R 53204-2008

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  ГОСТ Р 53204-2008

GOST R 53204−2008 nondestructive testing. Acoustic method of control of variable mechanical stresses. General requirements

GOST R 53204−2008
Group Т59

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Nondestructive testing

ACOUSTIC METHOD OF CONTROL OF VARIABLE MECHANICAL STRESS

General requirements

Non-destructive testing. Alternating stress evaluation by ultrasound. General requirements

OKS 77.040.10

Date of introduction 2010−01−01

Preface

The objectives and principles of standardization in the Russian Federation established by the Federal law of 27 December 2002 N 184-FZ «On technical regulation», and rules for the application of national standards of the Russian Federation — GOST R 1.0−2004"Standardization in the Russian Federation. The main provisions"

Data on standard

1 DEVELOPED by the Nizhny Novgorod branch of the Institute of mechanical engineering of the Academy of Sciences of the Russian Federation (NF IMASH) and the Autonomous nonprofit organization «Scientific-research center of control and diagnostics of technical systems» (ANO «nits KD»)

2 SUBMITTED by the Technical Committee for standardization TC 132 «Technical diagnostics"

3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology dated December 25, 2008 N 692-St

4 INTRODUCED FOR THE FIRST TIME

Information about the changes to this standard is published in the annually issued reference index «National standards», and the text changes and amendments — in monthly indexes published information «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in a monthly information index «National standards». Relevant information, notification and lyrics are also posted in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet

Introduction

To date, methods of experimental study of the stress state of structural materials based on the phenomenon of customroot almost ready for widespread use. General requirements control of mechanical stresses by the acoustic method reglamentary GOST R 52731.

The expansion of the use of provocations effect to control stresses generated in solids under the influence of variable loads, is of interest for specialists working in the area of control of mechanical stresses methods of customproperty. If the variables load can be considered quasi-static, i.e. the parameters of their changes in time are small in comparison with the frequency of the waves transmitted into the material, the phenomenon of «dynamic customproperty» can be used for estimation of variable values of stresses in the material of a technical object.

This standard will serve as methodological basis for application of the acoustoelasticity method for evaluation of variable values of stresses in the elements of structures subjected to various dynamic loads in the process of testing, commissioning and operation.

1 Scope

This standard applies to acoustic echo method for determining the range of variation of the voltage acting in the plane perpendicular to the direction of wave propagation.

The standard covers the determination of mechanical stresses varying with the frequency at least an order of magnitude lower fundamental frequency of the ultrasonic echo pulses.

This standard specifies the basic requirements to the procedure of determining the alternating voltage averaged over the material thickness and area of the ultrasonic beam, the structural elements of technical objects as by testing dynamic load, and in the process of operation.

2 Normative references

This standard uses the regulatory references to the following standards:

GOST R 52731−2007 nondestructive testing. Acoustic method of control of mechanical stresses. General requirements

GOST 12.1.001−89 System safety standards. Ultrasound. General safety requirements

GOST 12.1.004−91 System safety standards. Fire safety. General requirements

GOST 12.2.003−91 System safety standards. Equipment production. General safety requirements

GOST 12.3.002−75 System safety standards. The process of production. General safety requirements

Note — When using this standard appropriate to test the effect of reference standards in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet or published annually by the information sign «National standards» published as on January 1 of the current year and related information published monthly indexes published in the current year. If the reference standard is replaced (changed), when using this standard should be guided by replacing (amended) standard. If the reference standard is cancelled without replacement, then the situation in which the given link applies to the extent that does not affect this link.

3 Symbols and abbreviations

3.1 this standard applies the following designations:

3.2 this standard applies the following abbreviations:

OK — the object of control;

PN — voltage, variable in time;

SI — measurement means;

EAP — electro-acoustic transducer.

4 Requirements to safety of works

4.1 measurements and processing of their results allow operators with skills in the operation of equipment of ultrasonic nondestructive testing, able to use national and industry normative and technical documents on the acoustic control techniques, trained to work with used C and are certified for knowledge of safety regulations in the relevant sector of industry.

4.2 the work on defining the variables of mechanical stresses by the acoustic method, the operator should be guided by GOST 12.1.001, GOST 12.2.003,GOST 12.3.002 and rules of technical safety for operation of electrical installations, approved by Gosenergonadzor.

4.3 Work should be carried out in accordance with the safety requirements set out in the instruction manual of equipment, part of the used measuring instruments.

4.4 the methodology of acoustic measurements for a specific OK must be specify the requirements with which compliance is mandatory when working in the enterprise.

4.5 In organization of work control must be complied with fire safety requirements according to GOST 12.1.004.

5 Requirements for measuring instruments

5.1 as SI can be used installing collected from production equipment, and specialized instruments to determine the scope of PN-certified and verified in the prescribed manner.

5.2 SI should contain the set of EAP, providing radiation and reception of shear and longitudinal elastic waves.

5.3 the set SI should include a monitor that provides informative scan signal at least up to 1 NS per division horizontal scale.

5.4 C should be provided with a method of measurements and processing of their results.

6 requirements for the test object

6.1 OK in the areas of measurement should not contain discontinuities and defects.

6.2 surface Condition in the areas of measurements should provide the necessary sensitivity and stability monitoring of acoustic pulses.

6.3 Minimum thickness of material in the zone of measurement is determined by the pulse duration and the maximum attenuation of elastic waves and the condition of the reflecting surface.

6.4 If the survey is OK with curved surfaces are more preferable for measuring the surface are of the convex type.

7 preparation for the inspection

7.1 Preparation for control includes the following main stages:

— analysis of technical documents and preparation of survey map;

— preparation of areas of measurement.

7.2 the Order of analysis of technical documents and mapping surveys

7.2.1 based On the study of technical documents for the object set:

the thickness of the material is OK in the areas of measurement;

— the possibility of responsible nodes or structural elements undesirable alternating stresses affecting their performance;

— calculated and experimental information on the amplitude-frequency range of alternating loads, which the structure undergoes during tests or operation;

— tentative direction of action of the alternating voltage in each of the controlled components;

— any other information leading to the need for control of the alternating voltage;

brand material of controlled design elements.

7.2.2 On the basis of the analysis carried out in accordance with 7.2.1, and subject to the requirements of 5 map control object.

7.3 preparation of the object for acoustic measurements

7.3.1 In the areas of control must be prepared in flat areas with dimensions greater than the corresponding geometrical dimensions of the used EAP.

7.3.2 Surface prepared plots in the areas of measurement of mechanical treatment is adjusted to the degree of roughness and waviness for surveillance on the screen of the monitor device of the ultrasonic pulses detained as a material for at least 50−100 MS.

7.3.3 Area measurements number and bring in a map of acoustic control.

8 Procedure control

8.1 Selection of a test acoustic pulse

8.1.1 Installing the inverter of shear waves in the correct position for the direction of their polarization parallel to the intended direction of the action of the AC voltage.

Note — Since in this case the sensitivity of the acoustic method is the greatest, while monitoring results of the respective measurements will be essential.

8.1.2 On the screen of the monitor device, the observed pattern of echo pulses reflected from the boundaries of the structural element. Check the possibility of observation of the echo pulse, delayed in the material several tens of microseconds. The same thing is repeated for the other direction of the polarization vector of shear waves and for longitudinal waves.

Note — the Use of longitudinal waves is not required, they can be used as supplementary information to confirm the results of control by using shear waves.

8.2 Measurement of control delay of the echo pulse in the material

8.2.1 Determine the amount of delay of the control of the echo pulse relative to the first, the number of divisions of the video monitoring device or a precision delay line, according to GOST R 52731.

8.2.2 Measurement is carried out for two or, if necessary, for the three types of waves. Values , and log control.

Note — If possible, unload OK measure at 8.2 allow us to determine the constant component of the voltage in accordance with GOST R 52731.

8.3 measurement of the broadening momentum profile of the elastic wave

8.3.1 For shear waves (see 8.1.1) find on the screen of the monitor device of the first echo pulses and choose the intersection point of the fluctuation is zero, preferably in the middle of the pulse where the amplitude is maximum.

8.3.2 Maximum stretch vertical and horizontal axis of the picture on the screen so that there were one almost vertical line corresponding to the selected phase oscillations in the pulse.

8.3.3 Visually, on the divisions of the line scan video control device determines the width of the line showing the profile of the echo pulse on the screen. If the SI composition precision delay lines this operation is carried out.

8.3.4 the operations carried out for the echo pulse, delayed in the material 50−100 µs. The value is determined as the difference between the width of the line depicting the profile of the detainee echo pulse and the width of the line depicting the profile of the first echo pulse.

Note — If possible, implement the requirements 8.3.4 the sensitivity of the method should be 10−20 MPa, the values of the magnitude PN (for metals and alloys of industrial use). Otherwise, this value will be more.

8.3.5 Repeating operations 8.3.1−8.3.4 for shear waves perpendicular to the direction of the polarization vector of shear waves find .

8.3.6 Verify that the intended direction of the alternating voltage real. Assumption is correct, if the value is 2−3 times larger than the value .

Note — If the verification 8.3.6 gives the opposite result, and the direction of action of the AC voltage, most likely perpendicular. If the values and close the AC voltage, most likely acts at an angle to the selected axes. In this case, you should repeat the measurements by rotating the respective directions of polarization of the waves (more precisely determine the direction of the alternating voltage in this way is hardly possible).

8.3.7 To improve the reliability of inspection results allowed operations 8.3.1−8.3.4 for longitudinal waves. The found value must be 1.5−2 times less .

8.3.8 Dimension , and, if necessary, possibly performed several times, average measurement results of the log control.

9 Rules for processing results of measurements

9.1 the values of the magnitude PN acting within the subassembly perpendicular to the direction of propagation of the probing elastic waves, calculated by the formulas:

, (1)

, (2)

, (3)

where , , are the coefficients kostopoulou connection, material OK.

the relative broadening of the momentum profile of the elastic wave, where 1, 2, 3.

Note — , and in formulas (1) to (3) can be taken equal to their values, quantitatively determining the value of the normal custompage effect in structural materials.

9.2 Controlled size, was found according to the formulas (1) to (3) must be the same in the range of 10−20 MPa. Given that (1) primary (see note 8.3.1), the corresponding value should be the most reliable. With proper measurements of formula (2) and (3) help to verify this.

9.3 In case of impossibility of carrying out measurements, processing results by the formula (1) formula (2) and/or (3). The accuracy decreases.

9.4 value of the controlled parameter that are defined by the formulas (1) to (3), log control.

9.5 In the audit trail make the resulting value of PN scale on the subassembly defined by the formula (1) based on the data of the extra dimensions.

10 the Rules of registration of testing results

10.1 the results of the control record in the journal, the form of which is given in Appendix A.

Additional information to be logged, the order of registration and storage of the journal (or conclusion) should be set in the technical documents for the control.

10.2 If the measurements are part of the research work, the results of the measurements should be made in accordance with the General requirements and rules of registration of reports on research work.

10.3 the results of the survey should be maintained until the next control OK.

Annex a (recommended). Form of the journal determine the magnitude of the alternating voltage

Appendix A
(recommended)

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M.: STANDARTINFORM, 2009