GOST R 50965-96
GOST R 50965−96 Aluminum and aluminum alloys. Method for the determination of hydrogen in solid metal (with Change No. 1)
GOST R 50965−96
Group B59
STATE STANDARD OF THE RUSSIAN FEDERATION
ALUMINUM AND ALUMINUM ALLOYS
Method for the determination of hydrogen in solid metal
Aluminium and aluminium alloys. Method for determination of hydrogen in solid metal
OKS 77.120.10
GST 17 3230
Date of introduction 1997−07−01
Preface
1 DEVELOPED by JSC «Russian Institute of light alloys» (JSC VILS), Technical Committee TC 297 «Materials and semi-finished products from light and special alloys"
MADE the Main Directorate of standardization and certification of raw materials of Gosstandart of Russia
2 ADOPTED AND put INTO EFFECT by the Resolution of Gosstandart of Russia from 30 October 1996 N 607
3 INTRODUCED FOR THE FIRST TIME
4 EDITION with Change No. 1 adopted in November 2003 (IUS 1−2004)
1 Scope
This standard establishes the procedure for determination of hydrogen in aluminum and aluminum alloys the method of melting in a stream of inert carrier gas (when mass fraction of hydrogen is from 0.05 to 0.45 million).
(Changed edition, Rev. N 1).
2 Normative references
The present standard features 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 1012−72 aviation Gasoline. Specifications
GOST 2603−79 Acetone. Specifications
GOST 3022−80 Hydrogen technical. Specifications
GOST 18300−87 ethyl rectified technical. Specifications
GOST 21241−89 Tweezers medical. General technical requirements and test methods
GOST 24104−2001* laboratory Scales. General technical requirements
______________
* On the territory of the Russian Federation GOST R 53228−2008, here and hereafter. — Note the manufacturer’s database.
GOST 25086−87 non-ferrous metals and their alloys. General requirements for methods of analysis
GOST 29298−92* cotton and mixed household. General specifications
______________
* On the territory of the Russian Federation GOST 29298−2005, here and hereafter. — Note the manufacturer’s database.
(Changed edition, Rev. N 1).
3 General requirements
3.1 General requirements for methods of analysis GOST 25086 with the Supplement.
3.1.1 Mass fraction of hydrogen is determined on two samples from one sample, weighted with the error not more than 0.01 g For the result of the analysis be the arithmetic mean of results of two parallel measurements.
4 the Norm of the measurement error
The measurement procedure provides the analysis with an error not exceeding the values specified in table 1.
Table 1
In millions
| Mass fraction of hydrogen |
The margin of error |
| From 0.05 to 0.09 incl. |
0,03 |
| SV. Of 0.09 «to 0.18 « |
0,04 |
| «To 0.18» and 0.27 « |
0,05 |
| «0,27» 0,45 « |
0,06 |
5 the essence of the method
The method is based on melting of the sample, placed in a graphite crucible of a high frequency furnace in a stream of inert carrier gas (nitrogen) with the subsequent registration of the mass fraction of released hydrogen in the conductometric cell — katharometer.
6 Apparatus, materials and reagents
Analyzer to determine the mass fraction of hydrogen H-mat 2020 (Germany) or RH-402 (USA), submitted to the state register of measuring instruments.
Allowed the use of other equipment of similar purpose, providing the meteorological parameters specified in this standard, and certified in accordance with [2].
Standard samples of composition of the aluminum or aluminum alloys according to GOST 8.315 with a certified mass fraction of hydrogen from 0.08 to 0.5 million.
Carrier gas: nitrogen 99.999 [1].
The hydrogen of 99.95 GOST 3022.
Helium grade a [3].
Crucibles, graphite manufacturer of the analyzer or crucibles of appropriate sizes other manufacturers of graphite grade TG-1.
Acetone according to GOST 2603.
The technical rectified ethyl alcohol according to GOST 18300.
The aviation gasoline according to GOST 1012.
Laboratory scales according to GOST 24104.
Tweezers according to GOST 21241.
Baptiste GOST 29298.
(Changed edition, Rev. N 1).
7 Sampling and preparation of samples for analysis
7.1 a Sample selected based on regulatory documents of the relevant products.
Of solid metal (ingots, ingots etc. and semi-finished products) cut out the blank for the sample width and thickness from 10x10 up to 12x12 mm and a length of from 80 to 100 mm.
A sample of the liquid metal is poured into a thick-walled copper mold, where solidification of the billet to the sample eliminates the loss of hydrogen, provided the required quality of the workpiece to the correct shape and size, without cavities and cracks.
Requirements for the quality of the interior surfaces of the mold and metal spoons, where sampled, is intended to maintain the mass fraction of hydrogen with the value characterizing the analyzed melt.
7.2 a Sample manufactured in the form of a cylinder with a diameter of (9,0±0,01) mm and height (35,0±0,1) mm for units type H-mat height (25,0±0,1) mm for device type RH-402. The shape and dimensions of samples for other similar types of equipment are defined by the profile and dimensions of the graphite crucible.
Surface samples will be turned on a lathe without using cooling liquid.
From the sample cut the sample, it is not allowed to support it with tweezers. In carrying out the operations necessary to provide that the sample fell in the glass buxu underneath it.
Then the sample is clamped in the Chuck of the machine in the plastic collet and grind the second side. As the material of the collet is allowed to use a Teflon or tarname.
7.3 Before loading into the analyzer samples stored in glass buksh filled with acetone, no more than 5−6 h. For device RH-402 permitted to store samples in buksh without acetone.
7.2, 7.3. (Changed edition, Rev. N 1).
8 preparing the analyzer
8.1 preparing the analyzer (enabling, establishment of gas flows, setting the zero level of katharometer) is carried out in accordance with technical description and manual of the specific device used (further — the instruction).
8.2 calibrating the analyzer
In accordance with the instructions carried out the graduation of the analyzer.
8.1, 8.2. (Changed edition, Rev. N 1).
8.3 the Definition of amendments the reference experiment
8.3.1 To assess the quality of the batch of graphite crucibles in accordance with the instruction, determine an amendment in the reference experiment of an empty graphite crucible PKO-1, referred to the weight of the sample, the analysis mode (section 9), the value of which should not exceed 0.02 millionof hydrogen. The specified operation is carried out not less than five crucibles of the party. In accordance with PKO-1 the specified value for this batch of crucibles is used for testing.
8.3.2 Determine the amendment of the control and experience of the graphite crucible with the sample PKO-2, for which the sample past analysis of re-melted in the analysis mode (section 9). For device H-mat value of PKO-2 shall not exceed 0,03 millionof hydrogen. The obtained value of PKO-2 is introduced into the memory of the computer. PKO-2 is set as the arithmetic mean of two parallel definitions. For device RH-402, the value of PKO-2 shall not exceed the values for a specific analyte alloy specified in the Annex to the user.
(Changed edition, Rev. N 1).
8.4 Verify calibration analyzer is carried out at least once a month by analyzing a standard sample in accordance with the manual of the device. Requirements for the standard sample — 11.3. In case of deviation of the reproduced values of the mass fraction of hydrogen FROM from the certified to conduct correction values K-factor at the certified mass fraction of hydrogen in accordance with the manual of the analyzer.
9 analysis
9.1 the Sample is removed from buxy. If buksa filled with acetone, the sample was dried on a slide warmer air at a temperature of 40−50 °C. Further analysis is carried out in accordance with the instructions in the following modes. For device H-mat:
— degassing of the graphite crucible is empty when the input voltage of the HF generator (230±5) for (60±10) s;
— cooling of the empty crucible within (60±10) s;
— removal of the surface hydrogen from the sample when the input voltage of the HF generator (140±5) In the for (30±10) s;
cooling of the crucible with the sample for (60±10) s;
— melting of the sample when the input voltage of the HF generator (220±5) V. the Time of melting of the sample detects the optical-electrical analyzer system, which automatically turns off the heating at the time of melting.
Note — During the operation of melting it is necessary to visually observe the condition of the specimen. The time from the beginning of melting to the complete melting of the sample should not be more than 5, otherwise you must turn off the heating manually.
For device RH-402 operation analysis is carried out in accordance with the instructions specific for each analyzed alloy modes specified in the Annex to the instruction, the quality of surface treatment of samples should provide the number of «surface» hydrogen not exceeding the values specified in this application.
(Changed edition, Rev. N 1).
9.2 the Sample is removed from the crucible.
9.3 Analysis of the next sample is carried out at 9.1 and 9.2.
10 processing of the results
10.1 the Results of determining the mass fraction of hydrogen calculated automatically highlighted on the screen (in millions) and print.
10.2 the Permissible variation in results at a confidence level of 0.95 does not exceed the values specified in table 2.
Table 2 — Norms of permissible differences
In millions
| Mass fraction of hydrogen | The absolute maximum discrepancy | |
for convergence |
for reproducibility, | |
| From 0.05 to 0.09 incl. | 0,03 |
0,04 |
| SV. Of 0.09 «to 0.18 « | 0,04 |
0,05 |
| «To 0.18» and 0.27 « | 0,06 |
0,07 |
| «0,27» 0,45 « | 0,08 |
0,09 |
11 Operational control precision
11.1 Control of accuracy of analysis by following the method set out in this standard, is carried out using of state standard samples (GSO) the composition of the aluminum or aluminum alloy.
11.2 Control the accuracy of the analysis carried out in the same conditions as the sample analysis of aluminum and aluminum alloys. To do this, analyze a standard sample with the use of two parallel measurements. Mass fraction of hydrogen in the standard and the analyzed sample should not differ by more than two times.
11.3 the reproduced value of the mass fraction of hydrogen in a standard specimen be the arithmetic mean of results of two parallel measurements.
The analysis considered accurate if the absolute difference between the results of parallel measurements of the mass fraction of hydrogen not in excess of the allowable absolute differences of convergence, and the difference between the reproduced and certified mass fraction of hydrogen WITH does not exceed 0,71 , where
the norm of permissible differences of reproducibility (table 2).
11.4 If the specified ratio is not satisfied, the analysis according to this method cease to identify the causes of the increased deviation.
Annex a (informative). Bibliography
APPENDIX A
(reference)
[1] THE 6−21−39−79 Nitrogen calibration (Balashikha oxygen plant — Balashikha, Moscow region).
[2] PR 50.2.009−94* State system for ensuring the uniformity of measurements. The procedure for the testing and type approval of measuring instruments
_______________
* On the territory of the Russian Federation to apply the Procedure of testing standard specimens or measurement facilities for the purposes of type approval, the Procedure for approval of type of standard samples or type of measuring instruments, the Procedure for issuing certificates on approval of type of standard samples or type of measuring instruments, establishment and changing of the validity period of these certificates and the interval between verifications of measuring instruments, Requirements to the signs of type approval for standard samples or type of measuring instruments and their application, approved by order of Minpromtorg of Russia of 30 November 2009 # 1081, here and hereafter. — Note the manufacturer’s database.
[3] TU 51−940−80 Helium gas (compressed) purified grade «A"
Appendix a (Revised edition, Edit. N 1).
