GOST 24018.0-90
GOST 24018.0−90 heat-resistant Alloys on a Nickel basis. General requirements for methods of analysis
GOST 24018.0−90
Group B39
INTERSTATE STANDARD
ALLOYS HIGH-TEMPERATURE NICKEL-BASED
General requirements for methods of analysis
Nickel-based fire-resistant alloys.
General requirements for methods of analysis
ISS 77.120.40
AXTU 0809
Date of introduction 1992−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of metallurgy of the USSR
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from
3. REPLACE GOST 24018.0−80
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Item number |
| GOST 8.234−77 |
4 |
| GOST 8.326−89 |
5 |
| GOST 1770−74 |
4 |
| GOST 4517−87 |
6 |
| GOST 5632−72 |
1 |
| GOST 6563−75 |
4 |
| GOST 6709−72 |
6 |
| GOST 7565−81 |
2 |
| GOST 9147−80 |
4 |
| GOST 24104−88 |
3 |
| GOST 25336−82 |
4 |
| GOST 29227−91 |
4 |
| GOST 29251−91 |
4 |
5. Limitation of actions taken by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (ICS 11−95)
6. REPRINTING. August 2004
1. This standard establishes General requirements for methods of analysis of high-temperature Nickel-based alloys according to GOST 5632.
2. The selection and preparation of samples is carried out according to GOST 7565 or according to normative-technical documentation for specific products.
3. Weighing of sample the samples of metals and chemicals for preparing standard solutions is carried out on the laboratory scales General purpose according to GOST 24104* 2nd accuracy class with the largest weighing limit of 200 g with a permissible measurement error is not more than 0.0002 g or on any other scales that meets the specified requirements for their metrological characteristics. In standard methods of analysis can be provided for scales with a weighing precision batches of floodplains, their mixtures, indicators and other substances. Weighing precision of sample result in standard methods of analysis, specifying the number of decimal places.
________________
* From 1 July 2002 was put into effect GOST 24104−2001.
4. Used laboratory volumetric glassware and instruments according to the GOST 1770 (cylinders, beakers, flasks), 29251 GOST, GOST 29227 (burettes, pipettes), glassware and equipment according to GOST 25336, GOST 6563 (platinum Cup) glassware of glass-carbon brand SU-2000, dishes made of fluoroplastic. Allowed to use other measuring vessels, authorized by GOST 8.234 and satisfy his requirements for accuracy, and the use of other laboratory glassware and equipment that meets the requirements of GOST 25336, 9147 GOST, GOST 6563 and their operating conditions.
5. Use standardized means of measuring the analytical signal.
Allowed to use other measuring devices, certified according to GOST 8.326* and provide metrological characteristics, normalized in standard methods of analysis.
________________
* On the territory of the Russian Federation there are PR 50.2.009−94.
6. For the analysis used reagents qualifications OS.h. and H. h
Allowed the use of reagents other qualification providing metrological characteristics, normalized in standard methods of analysis.
Aqueous ammonia solution can be obtained by saturating distilled water with gaseous ammonia.
For the preparation of aqueous solutions of all reagents according to GOST 4517 and analysis used distilled water according to GOST 6709.
7. The purity of the metals used to prepare standard solutions for constructing calibration graphs, and preparation of artificial mixtures for control of correctness of the results of the analysis should be not less than 99.9%.
8. The concentration of solutions Express:
mass concentration g/DMg/cm
;
molar concentration — mol/DM;
molar concentration of equivalent (normality) mol/DM(n);
mass fraction, % (mass of the substance, or component, in grams referred to 100 g of substance / 100 g of solution);
volume fraction, % (volume in cubic inches, is related to 100 cmof solution);
the designated element in the alloys of expressing a mass fraction, %.
9. In terms of the «diluted 1:1, 1:2», etc. and the notation «1:1, 1:2», etc. the first digits denote the volumetric part of the dilute reagent (e.g. concentrated acids), the second volume of the solvent (e.g. water). If the standard does not indicate the concentration of the acid or aqueous ammonia solution, to a concentrated acid or concentrated ammonia solution.
10. Preparation of solutions and analysis after each addition of reagent or water (solvent) the solution was stirred.
11. The terms «room temperature», «warm» or «hot» water (or solution) means that the fluid has a temperature of respectively 15 °C to 25 °C, 40 °C to 75 °C and above 75 °C, if no other temperature of water (solution) in the standard methods of analysis.
12. When using physico-chemical methods of analysis it is necessary to choose optimal conditions of measurement of the analytical signal depending on the method used, the type of the used device, of the element and its mass fraction in the sample.
13. Calibration curve building in the system of rectangular coordinates: the abscissa shows the delay numeric value of the mass concentration, mass fraction or mass of an element in a specific volume of solution, the y — axis the value of the analytical signal, the value of the measured parameter or function from it.
Terms and method of construction of calibration curve indicated in the standard method of determining the mass fraction of the element.
Preparation of solutions for constructing the calibration curve performed simultaneously with the analysis of samples of alloy.
Allowed to apply the calibration function representing the equation of the calibration curve, and use the comparison method of the analytical signal of the sample with the analytical signal of standard solution of the element or of the solution of a standard sample, if it is stipulated in standard methods of analysis.
It is allowed to use the calibration factors, if pre-installed, for specific conditions of the analysis the calibration graph is rectilinear over the whole range of concentrations.
14. The mass concentration of the standard solutions prepared from metals or chemicals, if necessary, establish not less than three batches of the original substance or not less than three aliquote parts of a standard solution.
15. Mass fraction of the element in the sample and the standard sample determined in two parallel batches. When the divergence of parallel measurements above the permissible values regulated by the method of analysis, and differences in the assessment of the quality of the material samples is carried out in three parallel batches.
Simultaneously with the analysis under the same conditions conduct control expertise to make the relevant amendment in the result analysis.
A number of control experiments must match the number of parallel definitions in the analysis sample.
16. To control the error of the results of the analysis at least once per shift under the same conditions analyze the standard sample in two or three batches. For control choose a standard sample with a chemical composition corresponding to the requirements of standard methods of analysis.
In the absence of the standard sample and the control error of the result of the analysis carried out by the method of additions, the analysis of synthetic compounds or other methods. Monitoring the error of the result of the analysis by the method of additions is carried out by finding the mass fraction of the element in the analyzed material after adding aliquotes part of a standard solution of this component to the sample of analyte prior to analysis. The value of additives is chosen so to keep the optimum conditions of analysis provided by a particular standard methods of analysis. Carry out the determination of this element in the sample after the introduction of additives. The additive value calculated as the difference between the found values of the mass fraction of the element in the sample with the additive and without the additive.
17. The result of analysis of sample, standard sample or standard solution supplements taking the arithmetic mean of two (three) of parallel measurements taking into account an arithmetical mean of two (three) of parallel measurements in the reference experiment.
The numerical value of the result of the analysis of samples must contain the last significant digit in the same category in which it is in the appropriate value allowable discrepancies between the results of parallel measurements.
18. The absolute differences of the results of three parallel measurements (), calculated at a confidence level of 0.95 for the corresponding interval mass fraction of the element are presented in the tables on methods of analysis.
The values of permissible differences of two parallel definitions () find by multiplying the corresponding value
by a factor of 0.84. The absolute differences of the results of three or two parallel definitions should not exceed the values permitted by the differences
or
, respectively, of 0.84, and the average result of the analysis of a standard sample or a standard solution of the additive should not differ from the certified or installed in a standard solution the mass fraction of the element to a value of not more than 0.5
or 0.6
, respectively.
If the analysis results do not meet these requirements, the definition of the element in the analyzed sample and the standard sample again. If repeated results do not meet these requirements, the analysis is stopped until the detection of the causes of distortion of the results of the analysis, then the analysis is repeated.
