GOST R 56665-2015

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  ГОСТ Р 56665-2015

GOST R 56665−2015 nondestructive testing. Acoustic method for determination of residual stresses in the material of the rims of railway wheels. General requirements

GOST R 56665−2015
Group Т59

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Nondestructive testing

ACOUSTIC METHOD FOR DETERMINATION OF RESIDUAL STRESSES IN THE MATERIAL OF THE RIMS OF RAILWAY WHEELS

General requirements

Non-destructive testing. Ultrasonic method for determining the residual stresses in the railway wheel rims. General requirements

OKS 77.040.10

Date of introduction 2016−07−01

Preface

1 DEVELOPED by the Open joint-stock company «Scientific-research center of control and diagnostics of technical systems» (JSC «NIC KD») of Nizhny Novgorod state technical University n.a.R.E.Alekseev (NSTU them.R.E.Alekseeva)

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 22 Oct 2015 N 1616-St

4 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 official 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 upcoming issue of the 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 (www.gost.ru)

Introduction

The rims of railway wheels belong to the most important items of rolling stock, limiting the reliability and safety of operation.
The most important contribution to the technical condition of the rims along with the quality associated with the characteristics of the structure, mechanical and thermal processing, introduce residual stresses formed during manufacture and are redistributed due to the significant impact and cyclic loads.

Knowledge of the level of residual stresses in rims at any stage of operation of the car will significantly improve the accuracy of determining its technical condition and to prevent future accidents due to fatigue failure of the wheel.

Currently the most promising non-destructive methods of determination of mechanical stresses is the method of customproperty [1], [2].

A number of authors [3], [4] have convincingly shown the possibility of experimental determination of the level of residual stresses in rims of this method.

The existing normative documents — GOST R 54093, [5], [6] — provide ultrasonic testing of residual stresses in rims of railroad wheels, but the procedure of such control is presented in them is very incomplete.

This standard was developed in order to provide methodological basis for the application of the method of acoustic strain gauges for monitoring of residual stresses in rims of train wheels both in the laboratory and in operating conditions.

1 Scope

This standard applies to the acoustic method of determination of residual stresses in rims of solid-rolled railway wheels according to GOST 10791 wheel pairs of diesel locomotives, electric locomotives, diesel trains, electric trains, freight and passenger cars and special rolling stock with a design speed of over 250 km/h.

This standard specifies the basic requirements for a procedure for the determination of residual stresses in the material of the rims of railway wheels using a bulk shear wave propagating normal to the side surface of the rim.

Established by this standard method can be applied in-lab, bench and full-scale conditions controlling the residual stresses in the material of the rims of railway wheels.

2 Normative references

This standard uses the regulatory references to the following standards:

GOST 7.32−2001 System of standards on information, librarianship and publishing. The report on research work. The structure and rules of registration

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 12.1.038−82 standards System of labor safety. Electrical safety. The maximum permissible values of the touch voltage and currents

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

GOST 12.2.013.3−2002 electric Car manual. Private security requirements and test methods, grinding, disc grinding and polishing machines with rotational movement of the working tool

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

GOST 1497−84 Metals. Test methods tensile

GOST 2768−84 Acetone. Specifications

GOST 2789−73 surface Roughness. Parameters and characteristics

GOST 10587−84epoxy-Dianova uncured. Specifications
________________
Standard operates only on the territory of the Russian Federation.


GOST 10791−2011 solid-rolled Wheels. Specifications

GOST 17299−78 ethyl Alcohol technical. Specifications

GOST 28840−90 Machine for mechanical tests of materials

GOST 30489−97* (EN 473:1992) the Qualification and certification of personnel in nondestructive testing. General requirements
________________
* 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.

GOST R 8.563−2009 State system for ensuring the uniformity of measurements. Techniques (methods) of measurements

GOST R 12.1.019−2009 System of standards of occupational safety. Electrical safety. General requirements and nomenclature of types of protection.

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

GOST R 54093−2010 Wheels of railway rolling stock. Methods of determination of residual stresses

GOST R 55043−2012 nondestructive testing. Determination of the coefficients of elastic-acoustic coupling. General requirements

GOST R 55725−2013 nondestructive testing. Piezoelectric ultrasonic transducers. General technical requirements

GOST R ISO 5725−2-2002 Accuracy (trueness and precision) of methods and measurement results. Part 2. The basic method for the determination of repeatability and reproducibility of a standard measurement method

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 in the annual information index „National standards“ published as on January 1 of the current year, and the editions of the monthly information index „National standards“ for the current year. If replaced with a reference standard, which was given an undated reference, then it is recommended to use the current version of this standard, taking into account all enabled in this version modifications. If replaced with a reference standard, which is given a dated reference, it is recommended to use the version of this standard referred to above by year of approval (acceptance). If after approval of this standard in the reference standard, which is given a dated reference, a change affecting a provision to which reference, the provision is recommended to be applied without taking into account this change. If the reference standard is cancelled without replacement, the position in which reference is made to him, recommended to be used in part not affecting this link.

3 Symbols and abbreviations

3.1 this standard applies the following conventions:

h — the width of the rim of a railway wheel, mm;

 — the speed of propagation of elastic shear waves in the material of railway wheels, m/s;

 — the level of residual stresses equal to the difference between circumferential and radial stress, MPa;

 — delay of the second pulse of the reflected transverse wave relative to the first reflected pulse when the polarization of waves in the circumferential direction in the measurement area without residual stresses with repeated measurements, NS =1…n;

 — average delay of the second pulse of the reflected transverse wave relative to the first reflected pulse when the polarization of waves in the circumferential direction in the measurement area without residual stresses, NS;

 — delay of the second pulse of the reflected transverse wave relative to the first reflected pulse when the polarization of the wave in the radial direction in the area of measurement of residual stresses in repeated measurements, NS =1… n;

 — average delay of the second pulse of the reflected transverse wave relative to the first reflected pulse when the polarization of the wave in the radial direction in the area of measurement of residual stresses, NS;

 — delay of the second pulse of the reflected transverse wave relative to the first reflected pulse when the polarization of waves in the circumferential direction in the area of measurement of residual stresses in n repeated measurements, NS =1…n;

 — average delay of the second pulse of the reflected transverse wave relative to the first reflected pulse when the polarization of waves in the circumferential direction in the area of measurement of residual stresses, NS;

 — delay of the second pulse of the reflected transverse wave relative to the first reflected pulse when the polarization of the wave in the radial direction in the area of measurement of residual stresses in repeated measurements, NS =1…n;

 — average delay of the second pulse of the reflected transverse wave relative to the first reflected pulse when the polarization of the wave in the radial direction in the area of measurement of residual stresses, NS;

acoustic anisotropy in a zone of measurement of residual stresses in nrepeated measurements, =1… n;

 — the average value of the acoustic anisotropy in the measuring area without residual stresses;

acoustic anisotropy in the area of measurement of residual stresses in nrepeated measurements, =1…n;

 — the average value of the acoustic anisotropy in the area of measurement of residual stresses;

 — absolute accuracy of measurement of time intervals of the used measuring instruments NS;

 — maximum permissible relative error of measurement of time intervals of the used measuring instruments;

the variation coefficient values ;

the variation coefficient values ;

3.2 this standard applies the following abbreviations:

LCD train wheel;

OZHK — rim of a railway wheel;

IT is the residual voltage;

PEP — piezoelectric Converter;

SI — measurement means;

Wee — ultrasonic pulse;

EAP — electro-acoustic transducer.

4 General provisions

4.1 Measuring IT in OZHK carry out a method of customroot in accordance with the General requirements of GOST R 52731.

4.2 the Method is based on the existing in the field of elastic deformations of a linear dependence of velocity of propagation of bulk elastic waves in the direction perpendicular to the plane of action of the stresses, of mechanical stresses in the circumferential and radial directions.

4.3 material OZHK stress acting in the axial direction (along the axis of the wheel), small compared to the stresses acting in the circumferential and radial directions. Therefore, the stress state considered locally flat, dependence of velocity of propagation of bulk elastic waves from the axial stress is neglected.

4.4 manufacturing Technology of forged railway wheels according to GOST 10791предполагает formation in their rims considerable compressive tangential stress, significantly higher than the radial stress. As a consequence, the stress state OZHK without significant error in each control point can be considered to be uniaxial, and the residual voltage is calculated by formulas of customroot for uniaxial stress state in accordance with GOST R 52731.

4.5 To measure the use of the shear wave, polarized in the circumferential and radial directions.

The direction of wave propagation is axial (perpendicular to the lateral surface of OZHK).

4.6 diagram of the testing of the material corresponds to the echo method of ultrasonic testing. Method of excitation of elastic vibrations — pin. The form of the radiated signal is „pulse“ with a high-frequency (ultrasonic) filling the envelope smooth and effective duration (at the level of 0.6 of max. amplitude) 2 to 4 periods of the fundamental frequency.

4.7 Radiation and reception of acoustic signals provide by using direct combined or separated-combined EAP transverse waves.

Note — as EAP can be used in probes according to GOST R 55725 or electromagnetic acoustic transducers.

4.8 the Measured voltages are averaged by volume of the ultrasonic beam, determined by the transverse dimensions of the EAP and a width of OZHK.

4.9 the coefficients of the strain gauge (provocations) connection used to calculate IT from the measured acoustic delays are characteristics of the material, determined by the modules of its linear and nonlinear elasticity. The values of these coefficients for the material OZHK must be defined with the limit of permissible relative error of ±10%. Experimental determination of the coefficients of the strain gauge (provocations) communication is carried out in accordance with the requirements of GOST R 55043 and Annex A of this standard.

4.10 Recommended in this standard method can serve as the basis for the drafting of methods of measurements GOST R 8.563.

4.11 In developing the techniques of measurements must be verified on the basis of the representative database of tested LCD.

5 safety Requirements

5.1 measurements allow personnel trained, training in a timely manner, certified in voluntary certification system to the appropriate level of qualification according to GOST 30489 according to [7], [8].

5.2 Upon verification, the operator should be guided by GOST 12.1.001, GOST 12.2.003,GOST 12.3.002 and safety regulations for electrical installations according to GOST R 12.1.019 and GOST 12.1.038.

5.3 Measurement is carried out in accordance with the safety requirements specified in the operating instructions of the equipment, part of the used SI.

5.4 Facilities for measurements shall meet the requirements of standards [9],[10].

5.5 In the organization of control IT needs to be complied with fire safety requirements according to GOST 12.1.004.

6 Requirements for measuring instruments

6.1 as SI can be used installing collected from production equipment, and specialized instruments to determine time intervals between the repeatedly reflected UI, propagating in the material OZHK, certified and verified in the prescribed manner.

6.2 SI needs to provide the measurement of the echo method using the UI with a smooth envelope.

6.3 SI needs to provide the possibility of radiation and reception of UI with an effective rate of 2.5 to 10 MHz.

6.4 In the set SI must enter direct combined or separated-combined EAP, which provides radiation and reception of pulses of transverse elastic waves propagating normal to the surface OZHK.

Note — as a direct probe of the combined shear waves can be used converters „Panametrics“ (USA).

6.5 Documentation the SI shall contain the measurement procedure and the documents that establish:

— the purpose and scope SI;

— the composition and main characteristics of the hardware and software, including error of measurement of the parameters of the UI;

— methods and means of achieving the compatibility of SI, including data, electrical, energy, software, development, and operational.

6.6 description of the functionality of SI in the operational, engineering and programme documents should reflect the specifications of the hardware and software.

6.7 Operational characteristics of the SI must conform to the requirements of the specifications and of this standard.

6.8 Requirements for software of measuring instruments

6.8.1 Software SI shall provide the possibility of selecting any of the reflected UI and search for the required sampling points of the profile of pulses.

6.8.2 Primary acoustic information for each point of measurement should always be stored on external media, protected from unauthorized access.

6.9 Ancillary devices and materials when using piezoelectric transducers

6.9.1 Grinding tool for surface preparation according to GOST 12.2.013.3.

6.9.2 Degreasing liquid (alcohol according to GOST 17299 or acetone GOST 2768 for surface preparation).

6.9.3 couplant when using probes.

7 Requirements for building control

7.1 Before installing the EAP surface OZHK cleaned of dirt, scale, rust and degreased.

7.2 the Class of surface roughness at the point of measurements using the probe is not lower thanRa 2,5 (GOST 2789).

Note — When using the probe method does not provide the required accuracy of determining IT, if the surface roughness of OZHK Ra exceeds 2.5 µm according to GOST 2789.

7.3 When using the probe the viscosity of the contact liquid at the temperature of measurement should correspond to the viscosity of the epoxy resin at a temperature of 25 °C from 12 to 25 PA·s (GOST 10587).

8 preparation for measurement

8.1 Study certificates for material LCD.

8.2 On the basis of technical documentation determine the value of h at the measurement points.

8.3 On the basis of reference data or experimentally determined value .

8.4 Choose EAP, the effective pulse frequency which is 2.5 MHz.

8.5 Identify the location of the measuring points.

8.6 the state of the surface at selected points in compliance with the conditions of measurement (see 7.1, 7.2).

8.7 is Applied, if necessary, the layer of contact liquid on the prepared surface OZHK.

8.8 Install EAP on the surface OZHK, connect them to SI.

8.9 Include SI, check its performance when displaying video device timebase of the received signals.

8.10 On the screen of monitor device without significant visible distortions should be observed first and second bottom UI.

8.11 Verify the absence on the time scan additional pulses are caused by either having to measure additional reflecting surfaces (valid for operating conditions OZHK defects — layers, inclusions, etc., detected by ultrasonic flaw detection), or improper installation of the EAP relative to the boundaries of the surface OZHK.

8.12 Calculated actual relative error of determining delays TOU transverse elastic waves according to the formula

. (1)

8.13 In the event that the following inequality is satisfied , make the decision about carrying out measurements with a reduced compared to the error or replace SI for more accurate, providing performance ratio .

Note — an Acceptable value has a value of 10.

9 the procedures for measuring and processing the results

9.1 the measurement of the initial acoustic parameters corresponding to the absence of HE in the material OZHK, carried out at the point located at the same radius with a point control IT and spaced from the tread surface at a distance of 40 mm when measuring on the side opposite to the ridge OZHK.

9.2 is Applied (if necessary) the contact liquid.

9.3 Establish EAP polarization direction in the circumferential direction.

9.4 In accordance with the user manual SI are measuring delay , for =1.

Note — generally the smallest error in the measurement of delay provides a method of signal transfer through zero [11].

9.5 EAP Rotate 90°.

9.6 Conduct latency measurements for =1.

9.7 Action 9.4−9.6 repeat time 5.

Figure 9.8 an array of values according to the formula

. (2)

9.9 the Array of values to check for outliers in accordance with GOST R ISO 5725−2.

9.10 Determine the average value of acoustic anisotropy according to the formula

. (3)

9.11 calculate the coefficient of variation of measurement results according to the formula

. (4)

9.12 Compare the value with a valid value of the relative error , which is equal to or , where

, (5)

. (6)

If you ratio

, (7)

the calculated values of the acoustic anisotropy in a zone without IT choose the resulting value , otherwise the number of dimensions increase and the steps 9.3−9.12 repeat as long as the value of the coefficient of variation reaches a value .

Note — failure to meet the coefficient of variation of no more than decide about measuring IT with a smaller precision or about the impossibility of measurement.

9.13 Measurement and processing for 9.2−9.13 performed to control IT. Determine the average value of acoustic anisotropy for a material OZHK at the control of IT.

9.14 IT is for the control points are calculated by the formula

, (8)

where strain gauge (provocations) the factor D is determined according to shot R 55043−2012 (Appendix A).

Note — In accordance with the data of [12] for the material of the domestic LCD can be considered the coefficient D is approximately equal to 1.23·10MPa.

10 Rules for registration of measurement results

10.1 the results of the measurements are fixed in the Protocol, the form of which is given in Appendix B.

10.2 If you measure IT in material OZHK are part of the research work, the results of measurements issued in accordance with the requirements of GOST 7.32.

Annex a (mandatory). The definition of strain (provocations) coefficients

Appendix A
(required)

A. 1 Strain gauge (provocations) the factor D in the formula for calculating IT (8) is determined by conducting tensile tests on flat samples according to GOST 1497.

A. 2 Grade surface roughness of samples at the point of measurements — not less than Ra 2.5 churchyard 2789.

A. 3 For sample loading use of machines for mechanical testing of materials according to GOST 28840.

A. 4 Selection of test equipment is carried out so that the sample to produce a voltage at least 0.8.

A. 5 Testing machine should provide the necessary load with an acceptable voltage deviation not more than 1 MPa during the period of time required to conduct acoustic measurements (from 30 seconds to several minutes depending on the skill of the operator and used by the SI).

A. 6 Comprise the program step of loading the sample from the initial load corresponding to the value of uniaxial tension of not more than 0.1, until a load corresponding to 0.8. It is recommended to provide at least five levels of loading for the subsequent regression analysis of test results.

A. 7 Sample with the attached EAP put into the machine for mechanical tests, achieve proper alignment and attached to it a small load to ensure reliable fixation of the specimen in the grips.

8 A. At each step of loading are measuring delays of UI of two types:

 — delay MS for shear wave, polarized along the axis of loading;

 — delay MS for shear wave, polarized perpendicular to the axis of loading.

Measurements are conducted with increasing and decreasing load. Then the specimen is removed from the car. Each loading (up-down) is carried out three times. Before the new loading EAP remove and re-install on the sample.

A. 9 Conduct regression dependency handling) , ,

where , , , , — delays UI in the material of the specimen without load.

A. 10 Customplugin coefficients , determined in the following way:

equal to the tangent of the angle of inclination to the axis of the regression line ;

equal to the tangent of the angle of inclination to the axis of the regression line ;

A. 11 Strain (provocations) the factor D is calculated by the formula

. (A. 1)

Appendix B (recommended). Form of measurement Protocol

Appendix B
(recommended)

PROTOCOL
determination of residual stresses in the rim of railway wheels

Table B. 1 the results of the measurements

Bibliography

The electronic text of the document
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M.: STANDARTINFORM, 2016