GOST R 55080-2012

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  ГОСТ Р 55080-2012

GOST R 55080−2012 Cast iron. XRF technology

GOST R 55080−2012

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

CAST iron

XRF technology

Cast iron. Method of X-ray fluorescence (XRF) analysis

OKS 77.080.10
OKP 08 0000

Date of introduction 2014−01−01

Preface

1 DEVELOPED by Closed joint stock company «Institute of standard samples"

2 SUBMITTED by the Technical Committee for standardization TC 145 «monitoring Methods of steel products"

3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology dated 14 November 2012 N 778-St

4 this standard takes into account the basic regulatory provisions of the standard ASTM E 322−96 (2004)* «Method of x-ray spectral analysis of low-alloy steels and cast irons» [ASTM E 322−96 (2004). «Standard test method for X-ray emission spectrometric analysis of low alloy steels and cast irons», NEQ]
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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.

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 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 (gost.ru)

Introduction

This standard originally developed in connection with necessity of establishment of unified requirements for the chemical analysis of cast iron x-ray fluorescence method, as well as to meet modern requirements for measurement accuracy indicators of the quality of cast iron in the Russian Federation.

1 Scope

1.1 this standard specifies x-ray fluorescence method to determine the iron mass fraction of the following elements, %:

sulfur is from 0.002 to 0.20;

phosphorus from 0.005 to 2.0;

silicon from 0.10 to 5.0;

manganese is from 0.02 to 5.0;

chromium is from 0.01 to 35.0;

Nickel from 0.01 to 25.0;

cobalt, from 0.01 to 0.5;

copper, from 0.01 to 10.0;

aluminium — from 0.002 to 0.2;

molybdenum — from 0.001 to 5.0;

vanadium of 0.001 to 1.0;

Titan — from 0.001 to 0.5;

magnesium is 0.001 to 0.10.

1.2 this standard applies to the analysis of samples of cast iron having a diameter sufficient to overlap the hole of the receiver samples (tapes, camera).

2 Normative references

This standard uses the regulatory references to the following standards:

GOST 8.315−97 State system for ensuring the uniformity of measurements. Standard samples of composition and properties of substances and materials. The main provisions of the

GOST 12.0.004−90 System of standards of occupational safety. Organization of training safety. General provisions

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

12.4.009 GOST-83 System of standards of occupational safety. Fire fighting equipment for protection of objects. Principal. The accommodation and service

GOST 6456−82 emery Cloth sanding paper. Specifications

GOST 7565−81 (ISO 377−2-89) Iron, steel and alloys. Sampling method for determination of chemical composition

GOST 18300−87 ethyl rectified technical. Specifications

GOST 21963−2002 (ISO 603−15−99, ISO 603−16−99) cutting wheels. Specifications

GOST R 8.563−2009 State system for ensuring the uniformity of measurements. Methods of measurement

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

GOST R ISO 14284−2009 Steel and cast iron. Selection and preparation of samples for the determination of chemical composition

GOST R 52361−2005 Control of the analytical object. Terms and definitions

GOST R 52781−2007 grinding and grinding. Specifications

GOST R ISO 5725−1-2002 Accuracy (trueness and precision) of methods and measurement results. Part 1. General provisions and definitions

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, then the situation in which the given link applies to the extent that does not affect this link.

3 Terms and definitions

This standard applies the terminology according to GOST R ISO 5725−1, GOST R 8.563, [1]-[7], as well as the following terms with respective definitions:

3.1 the method of measurements; MI: the Set of operations and rules, which provide the results of measurements with the set characteristics of error (uncertainty).

3.2 standard sample of the material (substances): a sample of the material (substance), one or more properties of which are mounted metrological reasonable procedures, to which was appended a document issued by the competent authority containing the values of these properties, specifying the characteristics of the errors (uncertainties) and a statement of traceability.

3.3 standard sample type-approved: a Standard sample of the material (substances) that are recognized by the Federal body of Executive power of the Russian Federation, carrying out functions in the sphere of technical regulation and Metrology.

3.4 factory standard sample: a Standard sample of the material (substances) that are recognized by management.

3.5 analytical signal: the Signal contains quantitative information about the characteristics, functionally associated with the content item, and recorded in the analysis.

3.6 calibration characteristics: Functional dependence of analytical signal from the content of the element expressed as a formula, graph or table.

3.7 characteristics of the error of the results of the analysis: limit of the interval in which the measurement error is with confidence probability of 0.95.

3.8 measure of accuracy of analysis results: the values of the characteristics of the error (uncertainty) set for any result of the analysis obtained in compliance with the requirements and rules of this method in its implementation in a particular laboratory (corresponds to expanded uncertainty with coverage factor 2).

3.9 measurement uncertainty: a Parameter associated with the result of a measurement and characterizes the dispersion of values which can be attributed to the measurand.

3.10 standard uncertainty: Uncertainty of measurement expressed as a standard deviation.

3.11 the expanded uncertainty: the Rate determined by the interval around the expectation of measurements covering a large fraction of distribution of values that could reasonably be attributed to the measured characteristic.

3.12 precision: the Degree of closeness to each other of independent results of measurements obtained in a particular regulated conditions.

3.13 repeatability (precision): Precision under conditions in which the measurement results obtained by one method with the same equipment on the same surface of the sample in the same laboratory by the same operator, and almost at the same time.

3.14 inter-laboratory precision: Precision under conditions in which the measurement results obtained by variation of all the factors shaping the variability in the application of specific techniques in the laboratory.

3.15 reproducibility: Precision under conditions in which the measurement results obtained by one method on identical test items in different laboratories.

3.16 limit of repeatability (convergence):it is Allowed acceptance probability of 0.95 is the difference between the largest and smallest of the two single measurements obtained under conditions of repeatability.

3.17 the critical range: Allowed acceptance probability of 0.95 discrepancy between the results of individual measurements, obtained in conditions of repeatability.

3.18 limit intralaboratory precision: Permitted for the acceptance probability of 0.95 discrepancy between the two measurement results obtained in terms of the intralaboratory precision.

3.19 the limit of reproducibility: Acceptable for the accepted probability of 0.95, the discrepancy between the two analysis results obtained under conditions of reproducibility.

3.20 the ratio of control: a Numeric value that is a criterion for the recognition of the monitored indicator of the quality of the measurement results relevant (or not relevant) requirements.

4 Symbols and abbreviations

4.1 this standard applies the following designations:


 — the value of the mass fraction of element, %;

 — the limit of repeatability (convergence) measurement results for two parallel definitions;

 — standard stability control calibration characteristics;

that the standards of accuracy control of measurement results;

limit intralaboratory precision;

 — the limit of reproducibility;

 — the characteristic error of the result of analysis of 0.95;

 — the uncertainty of the measurement result;

 — the expanded uncertainty of the measurement result;

enrolment rate.

4.2 this standard applies the following abbreviations:

WITH a standard sample;

GSO standard sample type-approved;

SOP — standard sample of the enterprise.

5 the essence of the method

This method is based on dependence of the intensity of the characteristic fluorescence lines of the element from its mass fraction in the sample. Excited by the primary x-ray characteristic radiation of elements in the sample is decomposed into a spectrum with subsequent measurement of analytical signal and determining the mass fraction of elements using the calibration parameters.

6 Sampling and sample preparation

Sampling and sample preparation — according to GOST 7565, GOST R ISO 14284. The surface of the sample intended for irradiation, sharpen on the plane and, if necessary, wipe it with alcohol. On the surface are not permitted shells, slag inclusions, color tint and other defects.

7 measuring instruments, auxiliary equipment and materials

When measured using the following measuring instruments and other technical means:

— multichannel and scanning x-ray spectrometers;

— Of cast iron according to GOST 8.315 with the certified value of the mass fraction of elements in accordance with section 1 with an error not greater than 0.3 (in justified cases, 0.5) value accuracy specifications of the methodology;

abrasive — cutting machines;

— grinding (rough-sanding) machines;

— screw-cutting lathes;;

— grinding and polishing machines;

— cutting discs according to GOST 21963;

— cutting wheels according to GOST 21963;

grinding grinding circles GOST R 52781;

grinding sand paper, GOST 6456;

— ethyl alcohol according to GOST 18300;

— argon-methane mixture for spectrometers using flow-proportional counters.

Allowed the use of other measuring instruments, auxiliary equipment and materials ensuring the accuracy of the analysis required by this standard.

8 Algorithm measurement

The algorithm of measurement involves preparing x-ray spectrometer to work, the selection of conditions for analysis of samples of cast iron, the construction of calibration characteristics, analysis.

9 Operation preparation for measurement

9.1 preparation of the spectrometer for measurements carried out in accordance with the maintenance manual and operation of the facility.

9.2 Initial calibration of the x-ray spectrometer is carried out experimentally in the implementation of MI with the use of SLAs, SOPS and/or production of homogeneous samples analyzed by standardized or certified methods of chemical analysis and of appropriate composition and physico-chemical properties of the analyzed material.

9.3 To obtain the calibration characteristics it is recommended to use at least three samples.

9.4 Procedure the calibration is performed in accordance with the instructions for working with the software x-ray spectrometer.

9.5 Calibration characteristics are used to determine the mass fraction of the controlled elements, either directly or with the influence of the chemical composition and physico-chemical properties of the object.

9.6 in the use of x-ray spectrometers that do not have the software, the calibration is carried out in accordance with the manual. Calibration characteristics expressed in the form of a graph, formula or table.

9.7 When working on the x-ray spectrometers are needed daily and after repairs, check the position of the calibration characteristics (drift correction). The procedure for drift correction should be regulated by the manual of the device or other documents.

9.8 introduction to the measurement results of the amendments, taking into account the influence of the chemical composition, structure and other physico-chemical parameters of the analyzed samples.

10 the stability Control calibration parameters

10.1 stability Control calibration parameters is carried out at least once per shift for upper and lower limits of the measuring range with or WITH homogeneous samples. Allowed to control only the upper (lower) limit or mid-range.

For (samples) carry out two measurements in terms of repeatability and test acceptability of the obtained measurement results in accordance with 10.2.

10.2 If the results are acceptable, calculate the arithmetic mean value of the mass fraction of the element and determine the difference between the values of the mass fraction of the element by the formula

, (1)

where the value of the mass fraction of the element in THE (sample) obtained when building calibration characteristics.

10.3 If exceed the permissible value in accordance with table A. 1 (Appendix A), measurement is repeated. If duplicate measurements exceed the permissible value, carry out the recovery of the calibration characteristics.

11 measurements, verification of acceptability of results

11.1 carry out two measurements of the mass fraction of elements in the sample under conditions of repeatability.

Note — If you come to the analysis of two or three samples, as the individual definition take the definition made on the analytical surface of one sample.

11.2 the Absolute difference obtained by 11.1 measurement results are compared with the limit of repeatability , is given in table A. 1 of Annex A.

If the absolute difference between the two measurements does not exceed the limit of repeatability ,

, (2)

the results recognize acceptable and as finally reproduced the result of taking the arithmetic mean value of two determinations.

11.3 If condition (2) is not satisfied, spend another definition and calculates the difference between the maximum and minimum results definitions. The obtained value is compared with the critical range shown in table A. 1 (Appendix A).

If the absolute difference between the results of the three measurements does not exceed the limit ,

, (3)

the results recognize acceptable and as finally reproduced the result of taking the arithmetic mean value of three measurements.

11.4 If the condition (3) is not performed, the measurement results in a series of ascending and as a final result take the value of the second lowest dimension with the subsequent identification and elimination of reasons for excessive scatter of results.

11.5 Numerical value of the result of the analysis must end with the same number of discharges, and the corresponding value characteristics error of the result of the analysis shown in table A. 1 of Annex A.

12 quality Control of measurement results

12.1 Control of correctness of analysis results

12.1.1 Control of the correctness is carried out by selective comparison of the results of spectral analysis of samples with chemical analysis results, perform standardized or certified methods. The ratio control is presented in table A. 1 (Appendix A).

12.1.2 In case of impossibility of fulfilling the requirements of 12.1.1 in full methods of chemical analysis can be performed control of the correctness of the measurement results of reproduction of the certified values of mass fractions of elements in GSO or SOP. The ratio control is presented in table A. 1 (Appendix A).

12.1.3 the Number of results in the control of accuracy must be not less than 0.3% of the total number of definitions for a controlled period.

12.1.4 measurement Accuracy is considered satisfactory if the number of mismatches results in excess of the allowable value or is not more than 5% of the number of monitored results.

12.2 Control intralaboratory precision of the measurement results

12.2.1 order to control intralaboratory precision results of measurements performed to determine the mass percentage of the elements in the previously analyzed samples, changing the influencing factors (different times, different operators, etc.).

12.2.2 the Number of repetitions should be at least 0.3% of the total number of measurements over a controlled period.

12.2.3 inter-Laboratory precision of the measurement results is considered satisfactory if the number of discrepancies between the results of primary and repeated tests, in excess of the permissible limit value intralaboratory precision Rn, are given in table A. 1 is not more than 5% of the number of monitored results.

12.3 subject to the conditions of sections 11 and 12 feature error (extended uncertainty) of measurement result shall not exceed the values given in table A. 1.

13 Making measurements

The results of the measurements draw up a Protocol, a journal entry or record in electronic media.

Together with the results of measurements represent the characteristics of error (extended uncertainty ) in the form:

, (4)

where is the result of the measurement item in the sample;

 — value characteristics error of the measurement result (an expanded uncertainty).

Note — Instead of specifying the characteristics of the error (extended uncertainty) is allowed to accompany the result with reference to this standard.


In the case where the final measurement result take the median measurement result is present without specifying the characteristics of the error.

14 Control the admissibility of the results of measurements obtained under conditions of reproducibility

The results obtained in two laboratories to recognize acceptable if the absolute difference between them does not exceed the limit of reproducibility given in table A. 1 (Appendix A).

15 the Requirements for staff qualifications

Measurements can conduct operator, skilled work on the x-ray spectrometer.

16 safety Requirements

When performing measurements it is necessary to comply with the requirements of the following documents:

— sanitary rules [7];

— sanitary rules and regulations [8];

— GOST 12.0.004 (organization for the education of working occupational safety);

— GOST R 12.1.019 (electrical safety when working with electrical installations);

— GOST 12.1.004 (fire safety requirements);

— GOST 12.4.009 (extinguishing media);

— requirements of safety instructions, operating in the laboratory.

Annex a (mandatory). The limits of repeatability, reproducibility, and standards control

Appendix A
(required)

Table A. 1

Percentage

Bibliography

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UDC 669.14:620.196.2:006:354 OKS 77.080.10 OKP 08 0000

Key words: cast iron, XRF technology, calibration characteristics, standards of accuracy
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