GOST 23328-95

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  ГОСТ 23328-95

GOST 23328−95 zinc Alloys. Methods of spectral analysis

GOST 23328−95

Group B59

INTERSTATE STANDARD

ZINC ALLOYS

Methods of spectral analysis

Zinc alloys. Methods of spectral analysis

OKS 77.120*
GST 17 2140
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* In the index «National standards» in 2007.
OKS 77.120.60. — Note the manufacturer’s database.

Date of introduction 1997−01−01

Preface

1 DEVELOPED by the Donetsk state Institute of non-ferrous metals (Danism), (MTC 107)

SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification

2 ADOPTED by the Interstate Council for standardization, Metrology and certification on April 26, 1995 (minutes N 7 MGS)

The adoption voted:

3 Decree of the Russian Federation Committee on standardization, Metrology and certification dated June 19, 1996, No. 409 of the interstate standard GOST 23328−95 introduced directly as state standard of the Russian Federation from January 1, 1997

4 REPLACE GOST 23328−78

1 SCOPE

This standard specifies atomic emission method for the determination of the content shown in table 1 elements in samples of zinc casting and anti-friction alloys.


Table 1

2 NORMATIVE REFERENCES

The present standard features references to the following standards:

GOST 8.315−91 GSI Standard samples. The main provisions, the order of development, certification, approval, registration and application*
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* Valid GOST 8.315−97, here and hereafter. — Note the manufacturer’s database.

GOST 10157−79 Argon gaseous and liquid. Specifications

GOST 24231−80 non-ferrous metals and alloys. General requirements to selection and preparation of samples for chemical analysis

GOST 25086−87 non-ferrous metals and their alloys. General requirements for methods of analysis

3 THE ESSENCE OF THE METHOD

The method is based on the excitation radiation of atoms of the sample analyzed alloy in electric discharge, the decomposition of the radiation into a spectrum, registration of the analytical signals proportional to intensity of spectral lines and subsequent determination of the values of the mass fraction using the calibration parameters.

4 EQUIPMENT AND MATERIALS

Photoelectric atomic emission spectrometers.

Argon gas of the first and higher grades — according to GOST 10157.

Cleaner for drying and purification of argon.

Air conditioners provide a constant temperature and humidity.

The lathe or other equipment for the preparation of samples for analysis.

Tungsten electrodes are in the form of bars with a diameter of 1−6 mm and coals spectral brand G3 with a diameter of 6 mm.

Standard samples (CO) — according to GOST 8.315.

Allowed to use other equipment and materials ensuring the accuracy of the analysis required by this standard.

5 PREPARING FOR ANALYSIS

5.1 General requirements — according to GOST 25086.

5.2 Selection and preparation of samples for analysis is carried out in accordance with GOST 24231 normative and technical documents regulating the requirements to the quality of casting or zinc antifriction alloys.

5.3 Analyze the surface of the samples sharpened on a lathe. Sharpened the plane of the sample should be flat, smooth, without shrink holes, pores, cracks, slag and non-metallic inclusions. Preparation of the analyzed surface is performed directly before analysis.

5.4 Preparation of spectrometer measurements carried out according to the instruction manual.

5.5 the Graduation of the spectrometer is carried out at the composition of the zinc alloys. Processing the analyzed surfaces and samples must be identical.

5.6 Calibration characteristics established taking into account the influence of the chemical composition and physico-chemical properties and a test portion, expressed in the form of the relation equation, graphs, or tables.

Allowed the use of calibration parameters, corrected, correcting the influence of the chemical composition.

For the spectrometer, interfaced with a computer, the procedure of calibration is determined by the software.

6 ANALYSIS AND PROCESSING OF RESULTS

6.1 Conditions of analysis are given in Appendix A.

6.2 the wavelengths of spectral lines and the range of values of mass fractions of elements are given in Appendix A.

6.3 allowed to use other conditions analysis and spectral lines, ensuring the accuracy of the analysis required by this standard.

6.4 sample Analysis is performed in two parallel determinations. The result for the parallel determination of taking the result of the registration of the analytical signal expressed in units of mass fraction of the element.

Allowed the execution of three parallel measurements.

6.5 the discrepancy between the results of parallel measurements of the analytical signal expressed in units of mass fraction element must not exceed the permissible confidence probability of 0.95. The permissible variance is calculated by the formula

, (1)

where or 2,77 3,31 — critical value of the ratio of the magnitude of the results of two or three parallel definitions, respectively to the average quadratic deviation at p = 0.95;

 — the relative standard deviation characterizing the convergence of the results of parallel measurements. The values given in table 2;

 — the arithmetic mean of the results of parallel measurements.


Table 2

6.6 the analysis result should be the arithmetic mean of the results of parallel measurements that meet the requirements of 6.5.

7 CONTROL OF ACCURACY OF ANALYSIS RESULTS

7.1 Control of accuracy of analysis results is carried out using the composition. The frequency control sets given the stability of the calibration parameters for each specific atomic emission spectrometer.

7.2 an Extraordinary control of accuracy of analysis results is carried out after repair, prevention of the spectrometer or changes in the terms of analysis.

7.3 Control the convergence of the results of parallel measurements of mass fractions of elements and samples is carried out in accordance with 6.5.

7.4 Control of reproducibility of results of analysis performed by defining the mass percentage of the elements in co and/or previously analyzed samples.

Discrepancies in the results of primary and repeated analysis of the same sample or must not exceed the permissible (confidence probability 0,95) calculated by the formula

, (2)

where 2,77 — critical value of the ratio of the magnitude of the two results of the analysis to their average quadratic deviation at p = 0.95;

 — the relative standard deviation characterizing the reproducibility of the results.

The values given in table 2;

 — the arithmetic mean of the results of the initial and re-analysis or certified value of the mass fraction of the element.

7.5 If the verification of the analysis results using the differences between the reproduced and certified mass fractions of the element WITH no more than 0.4.

7.6 in case of control of correctness by selectively comparing the results of atomic-emission analysis of samples from the result of the analysis of the same samples obtained on other standardized or certified methods shall satisfy the condition:

,

where  — tolerated another technique the discrepancy between the results of the analysis of the same sample.

7.7 If the discrepancy between the results of parallel measurements or the discrepancy between the results of the analysis at 7.4−7.6 exceeds the permissible value, the analysis is repeated.

If and when re-analysis of the divergence exceeds the allowable value, the results of the analysis, recognize the wrong and stop measuring to ascertain and eliminate the causes of violation of the normal course of analysis.

7.8 the results of the analysis of several samples taken from the same batch of alloy, can only be interpreted taking into account the heterogeneity of the party, errors in sampling, etc.

Annex a (recommended)

Table A. 1 — requirements analysis

Table A. 2 — Length of spectral lines and ranges of values of mass fractions of elements

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* Dimension corresponds to the original. — Note the manufacturer’s database.