GOST R 54487-2011
GOST R 54487−2011 nondestructive testing. Determination of gas porosity of cast aluminum alloys using the acoustic method. General requirements
GOST R 54487−2011
Group Т59
NATIONAL STANDARD OF THE RUSSIAN FEDERATION
NONDESTRUCTIVE TESTING
Determination of gas porosity of cast aluminum alloys by acoustic method
GENERAL REQUIREMENTS
Non-destructive testing. Evaluation of gas porosity in aluminium casting alloys by ultrasound. General requirements
OKS 77.040.10*
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* ICS 9−2012 GOST R 54487−2011 is with ACS
— Note the manufacturer’s database.
Date of introduction 2012−12−01
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 Autonomous non-commercial 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 November 9, 2011 N 521-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
Gas porosity is one of the commonly detected types of marriage castings. A thin shell or the pores in the metal are caused by release of absorbed gases, they are in the process of solidification of the metal.
The pores are the internal volume defects. They can degrade the characteristics of metal, for example to reduce the strength, decrease the ductility, deteriorate stanoevski and other important consumer characteristics.
The currently used visual method of determination of gas porosity being quite time-consuming for testing specimens cut from ingots or castings, and are not applicable for finished products. In addition, the visual method makes no assumptions about the characteristics of pores distributed across the volume of the material.
In recent years, actively developed equipment and methods for non-destructive acoustic testing to determine the parameters of the structure and physico-mechanical characteristics of structural materials. The fact of the dependence of ultrasound attenuation coefficient from the value of porosity is properly installed and is being increasingly used in engineering practice [1, 2].
This standard is designed to provide a methodological basis for the application of the acoustic method for rapid determination of gas porosity of cast aluminum alloys, both samples and structural elements.
1 Scope
This standard applies to acoustic echo method for the determination of gas porosity of the samples and structural elements manufactured out of cast aluminum alloys (ingots or castings) and having two plane-parallel surfaces at the point of measurement.
The standard establishes the basic requirements to the procedure of determining the average thickness of material and area of the ultrasonic beam gas porosity using bulk ultrasonic waves propagating through the thickness of the sample material or subassembly. Installed standard method can be applied both in laboratory studies and in the conditions of operation of technical objects for various purposes.
2 Normative references
This standard uses the regulatory references to the following standards:
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 12.1.005−88 standards System of labor safety. General hygiene requirements for working zone air
GOST 12.1.019−2009* the System of occupational safety standards. Electrical safety. General requirements and nomenclature of types of protection
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* Probably a mistake of the original. Should read: GOST R 12.1.019−2009, here and hereafter. — Note the manufacturer’s database.
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 12.2.013−91* the System of occupational safety standards. Machines manual electric. General safety requirements and test methods
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* Probably a mistake of the original. Should read: GOST
GOST 12.3.002−75 System safety standards. The process of production. General safety requirements
GOST 32−74 Oil turbine. Specifications
GOST 1583−93 Alloys aluminum casting. Specifications
GOST 2768−84 Acetone. Specifications
GOST 2789−73 surface Roughness. Parameters and characteristics
GOST 6259−75 Reagents. Glycerin. Specifications
GOST 17299−78 ethyl Alcohol technical. Specifications
GOST 26266−90 nondestructive testing. The ultrasonic transducers. General technical 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 notation.
| — the minimum value of the nominal frequency of the transducer used, MHz; | |
| — the maximum value of the nominal frequency of the transducer used, MHz; | |
| — the number of nominal frequency of the transducer used | |
| — the nominal frequency of the used piezoelectric transducers MHz; | |
— amplitude signals at a given amplification factor and frequency | |
|
— the coefficients calculated by the formulas |
.3.2 this standard applies the following abbreviations.
GP — gas porosity;
PEP — piezoelectric Converter;
OK — the object of control;
SI — a means of measurement.
4 General provisions
4.1 Method based on the use of the relationship between the attenuation coefficient of ultrasonic waves and the linear score GP aluminum alloys.
4.2 the Effect of GP on frequency dependence of ultrasound attenuation coefficient allows the use of a relatively simple methodology of acoustic measurements, enables rapid determination of the average score of GP in the range from 1 to 5 points according to GOST 1583 with an error of not more than 1 score.
4.3 method using the manual ultrasonic pulse-echo contact testing using a combined or dual probe according to GOST 26266.
4.4 Optimal output «microburst» of high frequency (ultrasonic) filling the envelope smooth and effective duration (at the level of 0.6 of the maximum amplitude) 2−4 period of the fundamental frequency.
4.5 Determined by this method score GP foundry aluminum alloy is the volume average of the ultrasonic beam depending on the transverse dimensions of the transducer and thickness OK.
5 safety Requirements of the work
5.1 measurements and processing of their results allow operators with skills of operation of the ultrasonic control equipment that can use the standards and 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.
5.2 in the works, by definition, GP casting of aluminum alloys 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 consumers according to GOST 12.1.019 and GOST
5.3 Work is performed in accordance with the safety requirements specified in the operating instructions of the used SI.
5.4 General hygiene requirements for working zone air — according to GOST
5.5 At the organization of works on determination of GP cast aluminum alloys must be met fire safety requirements according to GOST
6 Requirements for measuring instruments
6.1 as SI apply collected from production equipment, or specialized ultrasonic devices (hereinafter the devices) are certified and verified in the prescribed manner.
6.2 Operational characteristics of the devices must conform to the technical requirements, passports and of this standard.
6.3 settings of the instrument used reference samples of GP, prepared in accordance with the requirements of GOST 1583 and having a score of porosity from 1 to 5.
6.4 When using the dual probe, the latter must satisfy the following requirements.
6.4.1 the distance between the exit points of the ultrasonic beam-emitting probe and the entry point of the host ultrasound probe must correspond to a single reflection from the inner surface OK.
6.4.2 the angles of the prisms PEP must ensure that no transformations of wave types upon reflection from the inner surface OK.
6.5 SI should contain the set of probes, providing radiation and reception of longitudinal elastic waves in the frequency range from to
. The choice of the nominal frequency of the probes produced as follows.
6.5.1 For test material experimentally selected value ,
corresponding to minimal and maximal values of ultrasound attenuation in the reference samples.
Note — Usually has a value of 0.5 to 1.25 MHz,
With 10−15 MHz.
6.5.2 the Minimum value must be equal to 5. For this purpose the frequency range from
to
is divided into octave bands, the boundaries of which should correspond to the nominal frequencies of the used probes:
Note — To reduce errors in determining the average score of GP may increase value through the use of additional nominal frequencies that are within the selected octave bands.
6.7 Auxiliary devices and materials
6.7.1 Grinding tool for surface preparation — according to GOST
6.7.2 Degreasing liquid for surface preparation — alcohol according to GOST 17299 or acetone GOST 2768.
6.7.3 couplant, which use a special fluid is quite thick and well conducting ultrasound liquid (e.g., glycerin according to GOST 6259, autoly 6, 10, 18, compressor and other related oil according to GOST 32), wetting of the contact surface is OK, and probes.
7 requirements of the test object
7.1 measuring points on the surface OK there should be no shrinkage or porosity, Central porosity.
7.2 On the surface OK should not be slag and other foreign inclusions that are visible to the naked eye.
7.3 Minimum thickness of the material is OK at the measurement points should provide the possibility of obtaining on the screen of the monitor device of the reflected signal at the minimum frequency .
7.4 Maximum material thickness OK at the measurement points should provide the possibility of obtaining on the screen of the monitor device of the reflected signal at maximum frequency .
7.5 surface Temperature OK at the measurement points must be from 0 °C to 80 °C.
7.6 Before installing the probe surface OK cleaned of dirt, scale, rust and degreased.
7.7 Class of surface roughness is OK at the point of measurement is not lower than 1,6 according to GOST 2789.
7.8 in the presence of the weld distance from the measuring point to the weld should be at least twice the thickness of the OK button in the point measurements.
8 preparation for measurement
8.1 Study certificates for the material is OK.
8.2 Determine the location of the measuring points and choose a scheme for measuring the average score of GP.
8.3 Prepare the surface OK in the selected measurement points at 7.6−7.8.
8.4 the Dimensions of the prepared surface should be three times greater than the corresponding dimensions of the contact surface probes.
8.5 put a layer of contact liquid on the prepared surface OK.
8.6 turn on the device, check its performance when displaying video device timebase of the received signals.
8.7 Check on the time scan of additional pulses caused by the presence in the measuring point of the additional reflecting surfaces (faults, layers).
9 Order of measurements
9.1 transfer device in the operating frequency , is connected to the instrument probe with a nominal frequency
and set it to the surface OK on the selected measurement point.
9.2 Using adjusting the amplitude of the probe pulse, to achieve the amplitude of the reflected signal corresponding to the value of 0.5−0.7 of the vertical screen size of the video monitoring device. The obtained value of the amplitude of the signal is taken for the value .
9.3 without changing the adjustment of the amplitude of the probe pulse, take measurements of the amplitudes of the reflected signal for all nominal frequencies
in the selected measurement point.
10 Rules for processing results of measurements
10.1 On the reference samples receive a series of the calibration curves of the dependence 
Figure 1 is a Series of calibration curves CTAR (j)(i)
Figure 1 — Series calibration curves
In the figure the numbers of the curves correspond to the points of GP reference model.
10.2 On the basis of measurement results obtained in accordance with 9.2−9.3, calculate the values of the coefficients 
10.3 Building a graph of dependencies 
Figure 2 — Dependence of K_(j)(i) applied to a series of calibration curves
Figure 2 — Dependence is 
10.4 From the calibration curves 
10.5 as the average score of GP according to GOST 1583 for the investigated OK in the measuring point taking the score corresponding to the rating curve 
11 Rules of registration of results of measurements
11.1 the Results of measurements record in the journal, the form of which is given in Appendix A.
For more information, subject to registration, processing and storage of the journal (or conclusion) should be set in the technical documents for the control.
11.2 If the definition points GP cast aluminum alloys are part of the research work, the results of measurements issued in accordance with the General requirements and rules of registration of reports on research work.
Annex a (recommended). Form of measurement Protocol
Appendix A
(recommended)
| «CLAIM» | |||||||||||||||
| Head | |||||||||||||||
| name of the organization | |||||||||||||||
| personal signature | initials, surname | ||||||||||||||
| «____"________________20_____G. | |||||||||||||||
| PROTOCOL measure the average score of gas porosity | |||||||||||||||
| [object of control (OK), controlled phase OK] | |||||||||||||||
| 1 measurement date | |||||||||||||||
| 2 organization conducting the measurement, | |||||||||||||||
| 3 the owner of the object | |||||||||||||||
| 4 Data OK: | |||||||||||||||
| — the appointment | |||||||||||||||
| — the manufacturer, the manufacturing technology OK | |||||||||||||||
| — the thickness is OK at the point of measurement | |||||||||||||||
| — surface condition | |||||||||||||||
| — for more information about OK | |||||||||||||||
| 5 Sketch of OK indicating the location of measurement points and their numbering (in the app) | |||||||||||||||
| 6 Data on material is OK: | |||||||||||||||
| — manufacturer | |||||||||||||||
| — material grade (indicating the state standard or another normative document) | |||||||||||||||
| — production technology | |||||||||||||||
7 the Number of nominal frequency of the transducer | |||||||||||||||
| 8 the Nominal frequency of the transducer, MHz | |||||||||||||||
Table 1 — Values of coefficients
| … |
| Score of gas porosity according to GOST 1583 | ||||
| The research done by the operator | ||||
| personal signature | initials, surname | |||
| Head of laboratory | ||||
| NDT | personal signature | initials, surname | ||
Bibliography
| [1] | Adler L. Ultrasonic method to determinate gas porosity in aluminium alloy costings: theory and experiment. — J. Appl. Phys., 1986, V. 59, N 2, p.336−347. |
| [2] | Burd, M. B., GITIS M. B. On possibility of control of the porosity of hot-rolled beryllium attenuation of ultrasound. — Destructive testing, 1989, N 1, pp. 81−88. |
The electronic text of the document
prepared by JSC «Code» and checked by:
the official publication of the
M.: STANDARTINFORM, 2012
