GOST 26473.0-85
GOST 26473.0−85 Alloys and alloys based on vanadium. General requirements for methods of analysis (Change No. 1)
GOST 26473.0−85
Group B59
STATE STANDARD OF THE USSR
ALLOYS AND MASTER ALLOYS BASED ON VANADIUM
General requirements for methods of analysis
Vanadium base alloys and alloying elements. General requirements for methods of analysis
AXTU 1709
Valid from 01.07.86
to 01.07.91*
_______________________________
* Expiration removed
by the decree of Gosstandart of the USSR from
(IUS N 8, 1991). — Note the manufacturer’s database.
DEVELOPED by the Ministry of nonferrous metallurgy of the USSR
PERFORMERS
Yu. A. Karpov, E. G. Nembrini, V. G., Miscreants, V. V. Nedler, V. M. Mikhailov, L. G. Agapova, G. N. Andrianov, A. V. Antonov, V. D. Dozen, M. A. Desyatkova, T. I. Kirillova, L. I. Kirsanov, I. E. Korepin, V. A. Orlova, N. Rasnitsyn, N. Suvorova, N. L. Tomasev, M. W. Schmidt, L. N. Filimonov
INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
Member Of The Board Of A. P. Snurnikov
APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on standards of 25 March 1985, N 751
The Change N 1, approved and put into effect by the Decree of the USSR State Committee on management of quality and standards from
Change No. 1 made by the manufacturer of the database in the text IUS N 2, 1990
1. This standard establishes General requirements for methods of analysis of alloys and master alloys based on vanadium.
2. The selection and preparation of samples for analysis is carried out according to normative-technical documentation.
3. For the taking of test portions used analytical laboratory scales VLR-20G, technical scales VPT-1, torsion scales W 500 GOST 13718−68 or scales of similar types.
4. Sample of samples analysed and the material used for the preparation of samples comparisons and standard solutions, as well as precipitation in gravimetric methods weighed on an analytical balance with an accuracy of 0.0002 g. more
Sample indicators for the preparation of solutions or mixtures of the tracer is weighed on the analytical or torsion balance with an accuracy of at least 0.001 g.
Sample reagents for the preparation of titrated solutions and support are weighed on a technical balance with an accuracy of at least 0.01 g, and marshes — with an error of less than 0.1 g.
5. For calcination and melting the batches of samples analysed with smoothly applied laboratory muffle furnace MP-2УМ or furnaces of the same type.
6. For heating solutions used electric cooker with a sealed coil according to GOST 14919−83.
7. For the analysis used a measuring laboratory glassware not lower than 2nd accuracy class according to GOST 20292−74* (burettes, pipettes) and GOST 1770−74 (cylinders, beakers, flasks), as well as glassware (beakers, conical flasks, funnels, conical, desiccators, etc.) according to GOST 25336−82, crockery and equipment (crucibles, boats, inserts for desiccators, etc.) according to GOST 9147−80, dishes made of transparent quartz glass (crucibles, flasks, test tubes etc.) according to GOST 19908−80, as well as crucibles and cups made of platinum according to GOST 6563−75, dishes made of glassy carbon brand SU-2000.
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* On the territory of the Russian Federation there are 29169−91 GOST, GOST 29227−91−29229−91 GOST, GOST 29251−91-GOST 29253−91. — Note the manufacturer’s database.
8. For the preparation of solutions and tests used distilled water according to GOST 6709−72 and reagents qualification not lower than h. d. a., unless other qualifications.
9. The purity of the metals used for the preparation of standard solutions needs to be not less than 99.9%.
10. Allowed the use of other equipment, materials, utensils and reagents, subject to obtaining the metrological characteristics are not inferior to the specified in the standard methods of analysis.
11. In standard methods of analysis used mass (grams per cubic decimeter) and molar (mole per cubic decimeter) of solution concentration.
In the expression «diluted 1:1, 1:2, etc.» the first digits stand for the volumetric part of concentrated acid, or any solution, the second volume of the water.
12. Preparation of solutions and analysis after each addition of the reagent the solution was stirred.
13. Allowed the sequential determination of several elements from the same sample after appropriate dilution and selection alikvotnih parts.
14. The mass concentration of the standard solutions (in its definition of gravimetric method), and mass concentration of the titrant at the designated element and the ratio of the volume of the solution (titrimetric methods) set and is calculated as the average result of at least three parallel measurements. The calculation is carried out to the fourth significant digit.
15. When photometric definitions build the calibration graphs, the x-axis of which lay the mass of the detectable component in micrograms in the total fotometricheskogo solution, and on the y-axis — averaged values of the optical densities of the corresponding solutions, which find during the procedure of solution preparation for the construction of calibration curve and measurement of their optical densities at least three times.
When construction of calibration curve and analysis use the same reagents and solutions. Simultaneously with the analysis of batch samples to check the calibration graph by repeating the procedure of its construction.
The method and the conditions for constructing a calibration curve specified in the relevant standard methods of analysis.
16. When photometric definitions it is allowed to use the calibration factors, if pre-installed, for specific conditions of the analysis (this method, this apparatus and this interval of mass fraction) of the calibration graph is rectilinear over the whole range of concentrations.
For each defined element of the calibration factor () is determined by several (at least three) standard photometrically solutions. The mass of the element in its standard fotometricheskogo solution must be either equal to the mass of the element in the analyzed volume fotometricheskogo solution, or exceed it by no more than 1.2 times, or less than not more than 1.2 times.
The calibration factor () for each of the standard solution fotometricheskogo-defined component calculated by the formula
where — the mass of the detectable component in
-fact fotometriya standard solution, µg;
— optical density
-solution mass of the detectable component
.
All the obtained values of the calibration factor to find the arithmetic average
where is the number of standard photometrically solutions.
17. The conditions for obtaining the calibration parameters for x-ray fluorescence, atomic absorption and spectral methods specified in the relevant standard methods of analysis.
18. The result of the analysis taking the arithmetic mean of two parallel definitions, each of which is made of a separate hinge.
The numerical value of the result of the analysis must end with the same number of discharges, and the corresponding value of acceptable divergence.
19. The difference between the highest and lowest of results of parallel measurements and the difference between the highest and lowest two results of the analysis shall not exceed the values permitted by the differences indicated in each standard for method of determination of the corresponding element for the confidence probability of 0.95.
20. In standard methods of analysis are given (in tables) permitted discrepancies for several values of the mass fraction of the element. Allowable differences for intermediate values of the mass fraction of the element are calculated by using linear interpolation.
21. The analysis is repeated if the difference between the highest and lowest results of parallel measurements or between analyses exceeds the value permissible discrepancies.
22. The analysis accuracy control using certified reference materials where certified value of the mass fraction of each of the designated components differs from the mass fraction of the same component in the sample not more than two times, and the mass fraction of related components that affect the analysis results is not less than half the limiting mass fraction of the respective components as indicated in the relevant standards.
The result of the analysis is considered correct if the absolute value difference was found between the mass fraction of the designated component in the standard sample and the corresponding certified value, specified in the certificate on the standard sample does not exceed the allowable divergence provided by the appropriate standard methods of analysis.
Allowed to control the accuracy of the analysis of standard samples of composition and standard samples of enterprises certified in accordance with GOST 8.315−78.
In the absence of standard samples of composition, apply the following methods of control.
22.1. In the presence of (for the same values of the mass fraction of the designated component) for the two methods of analysis to control the accuracy of the results compares the results of the analysis of one (control) samples, obtained by two methods.
The results of the analysis of series of trials considered correct if one of them (control) satisfy the inequality
where — the absolute value of the difference of the results of the analysis of the audit samples obtained by the two methods;
and
— the permissible differences between results of the two tests, appropriate methods of analysis.
22.2. The accuracy of photometric, titrimetric, spectral analysis methods (GOST 26473.1−85, GOST 26473.2−85, GOST 26473.3−85, GOST 26473.4−85, GOST 26473.6−85, GOST 26473.7−85, GOST 26473.8−85, GOST 26473.9−85) control, using synthetic mixtures simulating the composition of the analyzed samples.
Prepared synthetic mixtures of the two compositions, wherein a content of the designated components: metal — based alloy (alloys) and other components, the mass fraction of which in the alloy (alloys) of at least 1%. To do this in a quartz crucible or conical flask is introduced with a pipette the required volume of a standard solution containing 1 mg/cmof the designated component. The solution was evaporated under low heat (to avoid splattering) to a volume of 0.3−0.5 cm
. Then, the solution was added the substrate and other components, the mass of which is equal to the mass of the respective metals in the analytical portion of the alloy with the maximum content of these metals, permissible normative-technical documentation reglamentary requirements for the chemical composition of the alloys of this brand (if weight more than 10 mg administered a portion of the metal with the weight of less than 10 mg — a known volume of a standard solution).
In the preparation of a synthetic mixture of the first composition is administered a volume of a standard solution defined by the component, in which the mass of this component corresponds to the mass of the designated component in the analytical portion of the alloy with a minimum content allowed by the analysis method.
In the preparation of a synthetic mixture of the second composition is administered a volume of a standard solution defined by the component, in which the mass of this component corresponds to the mass of the designated component in the analytical portion of the alloy with the maximum content allowed by the analysis method.
In the preparation of synthetic mixtures the relative error in the introduction of the designated component must be less than
is the permissible difference between results of two parallel definitions of this component in the synthetic mix;
— the arithmetic mean of two parallel definitions (result of analysis) of the designated component in the synthetic mix.
The relative error in the introduction of a detectable component (a) is calculated according to the formula.
where is the maximum error in the calibration of volumetric flasks (
0,95);
— volume of the volumetric flask, cm
;
— the maximum error of the selection of this volume (
p = 0.95);
— volume aliquote parts of a solution component is taken for the manufacture of synthetic mixture, cm
;
— the maximum error of estimate of the actual mass value
determined component (
0,95) in synthetic mixtures, taking into account the error of weighing substances in which the component is introduced in the synthetic mixture, the error of establishing the content of the designated component in the substance and the errors of estimation
due to the possible presence of the detectable component in other substances used for preparation of synthetic mixture;
— estimated weight of the designated component in the substance taken to prepare the solution of this component.
Prepared according to two synthetic mixtures of the above composition and analyze them in the appropriate way.
The results of the analysis of series of trials I think is right, if the found value of the mass fraction of the designated component in the mixture of each composition differs from the calculated value of mass fraction of not more than the value of permissible differences.
The calculated value of the mass fraction calculated as the ratio of the mass of the detectable component in the volume of standard solution injected in the preparation of synthetic mixture to the mass of analytical sample sample
m.
23. It is allowed to control the precision of analysis results for photometric, gravimetric, titrimetric, and atomic absorption spectral methods and method of variation of batches. Thus from the analyzed samples take two sample one (control) sample having a mass two times less than the specified in the relevant standard methods of analysis, and carry out all the operations of analysis, respecting the optimum conditions of analysis provided by the standard methods of analysis.
The results of the analysis of series of trials considered correct if the absolute value of the difference of both results of the control samples (computed as the arithmetic mean of two parallel definitions of hitch weight, provided the appropriate method of analysis in half) does not exceed
is the allowable discrepancy between the results of two tests to determined the mass fraction.
24. Allowed to control the correctness of the results of the analysis for photometric, gravimetric, titrimetric, and atomic absorption spectral methods and the introduction of additives. Thus from the analyzed samples choose (control) sample was found with a mass fraction of the designated component.
The found value of the mass fraction () in % calculate weight (
) grams detectable component according to the formula:
where is the mass of the analyzed sample, g.
In a quartz crucible or conical flask (depending on further analysis) was injected by pipette this volume of the standard solution defined by the component, the mass of the detectable component which satisfies the requirement 
g — additive).
The solution was evaporated carefully (to avoid splashing!) to 0.3−0.5 cm, add a portion of the sample and conduct the analysis, following the optimal conditions provided by the relevant method.
The results of the analysis of series of trials considered correct if the absolute value of the difference () found value of mass fraction of the designated component (
in %) in the sample with the additive and the estimated value of this mass fraction (
in %) does not exceed
2),
where and
— the permissible discrepancy of the results of parallel measurements for the mass fraction of the component in the sample and in the sample with the additive, respectively.
The calculated value of the mass fraction () is calculated by the formula
where — the mass of the detectable component in the control sample, g;
is the mass additive, g;
is the mass of the analyzed sample, g.
25. Check the accuracy of the analysis of a series of samples of the alloys or alloys is carried out in accordance with the requirements specified in the method, upon receipt of the analysis of the relevant samples using the same reagents, solutions, instruments, materials that are used in the analysis of samples (lots of samples).
18−25. (Changed edition, Rev. N 1).
26. Security requirements for the chemical analysis of alloys and master alloys based on vanadium — according to normative-technical documentation.
The procedure and training in operating safety — according to GOST 12.0.004−79*.
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* On the territory of the Russian Federation GOST 12.0.004−90. — Note the manufacturer’s database.
