GOST 28052-97

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  ГОСТ 28052-97

GOST 28052−97 Titanium and titanium alloys. Methods for determination of oxygen

GOST 28052−97

Group B59

INTERSTATE STANDARD

TITANIUM AND TITANIUM ALLOYS

Methods for determination of oxygen

Titanium and titanium alloys. Methods of oxygen determination

ISS 120.50
AXTU 1709

Date of introduction 1999−01−01

Preface

1 DEVELOPED by all-Russian Institute of light alloys (JSC VILS), the Interstate technical Committee MTC 297 «Materials and semi-finished products made of special alloys"

INTRODUCED by Gosstandart of Russia

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 12−97, dated 21 November 1997)

The adoption voted:

The name of the state	The name of the national authority for standardization
The Republic Of Azerbaijan	Azgosstandart
The Republic Of Armenia	Armastajad
The Republic Of Belarus	Gosstandart Of Belarus
Georgia	Gosstandart
The Republic Of Kazakhstan	Gosstandart Of The Republic Of Kazakhstan
Kyrgyz Republic	Kyrgyzstandart
Russian Federation	Gosstandart Of Russia
The Republic Of Tajikistan	Tajikistandart
Turkmenistan	The main State inspection of Turkmenistan
The Republic Of Uzbekistan	Standards
Ukraine	Gosstandart Of Ukraine

3. The decision of the State Committee of the Russian Federation for standardization, Metrology and certification dated 14 April 1998 No. 119 interstate standard GOST 28052−97 introduced directly as state standard of the Russian Federation from January 1, 1999

4 REPLACE GOST 28052−89

1 SCOPE

This standard establishes the procedure for determination of oxygen in titanium and titanium alloys by neutron activation and method of reductive melting in a stream of inert carrier gas (when mass fraction of oxygen from 0.02 to 0.50%).

2 NORMATIVE REFERENCES

GOST 8.315−97 GSI. The standard samples. The main provisions, the order of development, certification, approval, registration and application

GOST 8.326−89* GSI. Metrological certification of measuring instruments
________________
* On the territory of the Russian Federation PR 50.2.009−94**here and hereinafter. — Note the manufacturer’s database.
** PR 50.2.009−94 abrogated on the basis of the order of the Ministry of industry and trade of 30.11.2009 N 1081. — Note the manufacturer’s database.

GOST 849−97* Nickel primary. Specifications
________________
* On the territory of the Russian Federation GOST 849−2008, here and hereafter. — Note the manufacturer’s database.

GOST 860−75 Tin. Specifications

GOST 1012−72 aviation Gasoline. Specifications

GOST 1435−90* Bars and rods of non-alloy tool steel. Specifications
________________
* On the territory of the Russian Federation GOST 1435−99, here and hereafter. — Note the manufacturer’s database.

GOST 1465−80 Files. Specifications

GOST 2603−79 Acetone. Specifications

GOST 2789−73 surface Roughness. Parameters and characteristics

GOST 4045−75 a Vice metalwork with a manual drive. Specifications

GOST 5556−81 Wool medical hygroscopic. Specifications

GOST 5583−78 Oxygen gas technical and medical. Specifications

GOST 9293−74 Nitrogen gaseous and liquid. Specifications

GOST 10157−79 Argon gaseous and liquid. Specifications

GOST 18300−87 ethyl rectified technical. Specifications

GOST 21171−80 Generators of neutrons. Types and basic parameters

GOST 21241−89 Tweezers medical. General technical requirements and test methods

GOST 22626−77 Generators of neutrons. General technical requirements

GOST 24104−88* laboratory Scales General purpose and model. General specifications
________________
* On the territory of the Russian Federation GOST 24104−2001, here and hereafter. — Note the manufacturer’s database.

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

GOST 25336−82 Glassware and equipment laboratory glass. The types, basic parameters and dimensions

3 GENERAL REQUIREMENTS

3.1 General requirements for methods of analysis GOST 25086 with the Supplement.

3.1.1 Mass fraction of oxygen in the analyzed alloys are determined on two samples 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.

3.2 Control of accuracy of analysis results is carried out after each calibration installation under the same conditions as the samples of titanium alloys, analyze standard samples (CO) composition of titanium or titanium alloy according to GOST 8.315 in two parallel definitions. The mass fraction of oxygen in the standard and the analyzed sample should not differ by more than two times.

For the mass fraction of oxygen in the standard sample be the arithmetic mean of results of parallel measurements.

The results of the analysis are considered accurate if the absolute value of the difference between the results of parallel measurements of oxygen not in excess of the allowable absolute differences of convergence, and the difference between the reproduced and certified mass fraction of oxygen in co does not exceed 0,71, where the norm of permissible differences of reproducibility.

4. THE METHOD OF NEUTRON ACTIVATION DETERMINATION OF OXYGEN

4.1 the essence of the method

The method is based on the use of nuclear reactions On (, ) N, occurring during the irradiation of sample with fast neutrons. Mass fraction of oxygen is determined by comparing the activity of the radionuclide nitrogen-16 in the analyzed sample with the activity of the same radionuclide in the test sample (the sample for monitoring).

4.2 Equipment, materials and reagents

The device for determination of oxygen types K-1, K-5, K-7 with a neutron generator of 14 MeV at 21171 GOST, GOST 22626, having a flow of at least 5·10with. The use of other installations of similar purpose, providing the meteorological parameters specified in this standard.

The radioactive source cesium-137 with an activity of not less than 4·10Bq (0.001 mg·EQ. radium).

Laboratory scales of the 2nd accuracy class according to GOST 24104.

Acetone according to GOST 2603.

The technical rectified ethyl alcohol according to GOST 18300.

Medical absorbent cotton wool GOST 5556.

Baptiste.

Sample checklist for monitoring (2 PCs) made of PMMA (NOn). May be used instead of polymethyl methacrylate any substance containing oxygen, with a constant and known stoichiometric composition; the mass of oxygen in the sample should be not less than 0.1 g. the sample material for monitoring should not be impurities of fluoride, boron, uranium and plutonium.

Standard samples (CO) composition of titanium or titanium alloy according to GOST 8.315 with a certified mass fraction of oxygen from 0.02 to 0.50%, for example, GSO N 3608−87 composition of titanium alloy grade ВТ16. View samples WITH (compact or noncompact) must correspond to the type of analyzed samples.

Transport containers, made from corrosion-resistant steel (for example, steel 12X18H10T according to GOST 5632) with a mass fraction of oxygen is less than 0.003%. Use transport containers made of other materials with low oxygen content, possessing sufficient mechanical strength and containing impurities of fluoride, boron, uranium and plutonium. In this case the mass fraction of oxygen , %, not to exceed the values calculated according to the formula

, (1)

where  — the minimum mass of the analyzed sample is calculated according to the formula 2, g;

 — weight of the shipping container,

4.3 security Requirements

4.3.1 Laboratory equipment for analysis must be placed in accordance with the sanitary rules of placement and operation of generators of neutrons N 673−76 approved by the Ministry of health.

4.3.2 the analysis it is necessary to observe basic sanitary work rules with radioactive substances and other sources of ionizing radiation OSP-72/87 N 4422−87 approved by the Ministry of health.

4.4 Sampling and preparation of samples for analysis

4.4.1 Samples for analysis are selected according to the normative documentation.

4.4.2 test sample is prepared:

disc diameter (36,0±0,1) mm and a height of (8,5±0,1) mm, which scroogled (radius 1 mm), — for K-1;

in the form of a cylinder with a diameter (18,0±0,1) mm, height (34,0±0,1) mm for K-5;

disc diameter (50,0±0,1) mm and a height of (15,0±0,1) mm, which scroogled (radius 1 mm), — for K-7.

The shape and dimensions of samples for other installations determined by the profile and dimensions of pneumopathy.

The value of the parameter of roughness of the processed surface should be not more than 2.5 µm according to GOST 2789.

4.4.3 non-compact samples of samples (pieces of wire, pellets, powder, etc.) analyze in their transport containers.

The mass of test sample , g, must exceed the value calculated by the formula

, (2)

where is the density of the analyzed sample, g/cm;

 — the internal volume of the shipping container, cm.

4.4.4 Before analysis, the samples (except for powder and granules) degreased with acetone, alcohol, dried in air, then weighed.

4.5 Preparation for assay

4.5.1 Preparation of units

Preparation plants and generators of neutrons to the analysis (the inclusion, adjustment, measurement of the background level) is carried out in accordance with their technical descriptions and operating instructions (further instructions).

4.5.2 Calibrating plants

The installation will graduate in operating mode measurement on two (installation types K-1, K-7) or one sample using a stationary monitor (installation type K-5).

The calibration coefficient , g·%, determined by the formula

, (3)

where  — the number of registered pulses from the sample to the monitoring or stationary monitor (to set the type To-5);

 — mass of oxygen in the sample for monitoring is located in the channel of the sample, g;

 — the number of registered pulses from a sample for monitoring is located in the channel of the sample.

Analysis of compact samples can be performed under condition 10, the noncompact — at a ratio of 2·10; otherwise, you should replace neutron tube neutron generator. The frequency of calibration is in accordance with the instructions

.

4.6 performance analysis

4.6.1 Analysis carried out in accordance with technical description and instruction.

4.6.2 For installations not equipped with system of rotation of the sample at the position of irradiation and measurement, the number of cycles of irradiation — measurement should not be less than four.

4.7 processing of the results

4.7.1 Mass fraction of oxygen in the test specimen , %, is calculated by the formula

, (4)

where is the calibration factor determined in accordance with 4.5.2, g·%;

 — the number of registered pulses from a test sample;

 — the number of registered pulses of the background in the channel portion;

 — mass of test sample, g;

 — the number of registered pulses of the background in the channel monitor.

For applications types K-1 and K-7 mass fraction of oxygen is calculated by using the arithmetic device.

4.7.2 When using transport containers should be correct for the mass fraction of oxygen in the material container and the air inside of it between the particles in the sample.

In this case, the mass fraction of oxygen in the test specimen , %, is calculated by the formula

, (5)

where  — mass fraction of oxygen calculated by the formula (4), %;

 — volume of test sample, cm;

0,03 — coefficient taking into account the fraction of oxygen in air (g/cm)·%.

Mass fraction of oxygen in the material of the shipping container determined by the preliminary analysis of empty container having openings for removing activated during irradiation of air from the internal volume.

4.7.3 Permitted discrepancies in the results with a confidence probability of 0.95 should not exceed the values given in table 1.


Table 1 — Norms of permissible differences

The mass fraction of oxygen, %					The absolute allowable difference, %
for convergence		for reproducibility
compact samples	non-compact samples	compact samples	non-compact samples
From 0.020 to 0.040 incl.					0,005	0,013	0,007	0,016
SV.	0,040	«	0,060	«	0,007	0,016	0,010	0,019
«	0,060	«	0,090	«	0,009	0,020	0,014	0,024
«	0,090	«	0,120	«	0,012	0,024	0,018	0,029
«	0,120	«	0,150	«	0,015	0,030	0,022	0,036
«	0,15	«	0,20	«	0,02	0,04	0,03	0,05
«	0,20	«	0,30	«	0,03	0,05	0,04	0,06
«	0,30	«	0,40	«	0,04	0,06	0,05	0,07
«	0,40	«	0,50	«	0,05	0,07	0,06	0,08

5 THE METHOD OF REDUCTIVE MELTING IN A CURRENT OF INERT CARRIER GAS

5.1 the essence of the method

The method is based on reaction of interaction of dissolved and bound oxygen with carbon of the graphite crucible at high temperature. The oxygen from the molten sample is released in the gas phase in the form of carbon monoxide. Carbon monoxide is supplied to the analyzer that provides quantitative analysis of the extracted gas.

5.2 the Equipment, materials and reagents

Express oxygen analyzers types RO-116 LECO company, 02A-2002 company LEYBOLD-HERAEUS, AK-7516 design NGO Chermetavtomatika and their modifications. Equipment must undergo metrological certification in accordance with GOST 8.326.

Allowed to use other equipment, providing the meteorological parameters specified in this standard.

For preparing samples for analysis and conduct analysis using the following materials and reagents.

Graphite crucibles manufacturers of analyzers or crucible marks UK-1 [1], TG-1 (in the drawing ФЭ7768003 «a») factory Elektrougli.

The brand of zeolite 5A.

A carrier gas.

Nitrogen calibration zero grade B [2].

Argon gas, the highest grade according to GOST 10157.

Nitrogen gas according to GOST 9293.

Oxygen gas according to GOST 5583.

Calibration gas mixture of carbon monoxide with nitrogen, grade B [3].

Standard samples of the composition of the titanium alloy according to GOST 8.315 with a certified mass fraction of oxygen from 0.02 to 0.50% (for example, GEO N 3608−87 the composition of the alloy titanium brand ВТ16).

Bars primary Nickel brand H1 or H2 according to GOST 849.

Bars of diameter 8 to 10 mm steel grade U8 or U12 GOST 1435.

Tin granulated stamps O1 or O2 according to GOST 860*.
______________
* List does not include the materials and reagents used in operating specific types of equipment and specified in the relevant instructions.

The needle according to GOST 1465.

Sewing manual for the GOST 4045.

The stopwatches.

Laboratory scales of the 2nd accuracy class according to GOST 24104.

Tweezers according to GOST 21241.

Desiccators with GOST 25336.

Acetone according to GOST 2603.

The technical rectified ethyl alcohol according to GOST 18300.

The aviation gasoline according to GOST 1012.

Magnesium perchlorate [4].

Baptiste*.
______________
* The use of other materials and reagents for the precision of the measurements is below the specified in this standard.

5.3 Preparation for assay

5.3.1 sample Preparation

5.3.1.1 Samples for analysis are selected according to the normative documentation on the specific products.

5.3.1.2 the surface of the sample should not have oxide films and contaminants.

Cylindrical specimens are machined on a lathe, avoiding the appearance of oxide tints (oxide films). The surface of the samples is rectangular in shape trimmed with needle files. Samples must not have cracks, burrs, pits.

5.3.1.3 Weight and dimensions of samples in accordance with the technical description of the analyzer.

5.3.1.4 Before analysis, the samples are degreased with benzene and acetone, then with alcohol, dried on a clean surface and weighed.

5.3.2 Preparation equipment

5.3.2.1 the Instrument is prepared to work in accordance with technical description and instruction manual (hereinafter manual).

5.3.2.2 Construction of calibration curve

Calibration curve in the coordinates «Temperature of the crucible, °C — voltage loads," building on the values of the melting points of pure metals in the temperature range tests of titanium alloys. Schedule build at initial startup of the equipment or the replacement of the party of crucibles.

5.3.2.3 Using the calibration curve, set the voltage load in the analysis and degassing in accordance with the temperature specified in table 2.

5.3.2.4 Preparation analyzers

For the preparation of the analyzers of the types of RO-116 and 02A-2002 using the calibration gas mixture of carbon monoxide with nitrogen in a volumetric proportion of carbon monoxide is not less than 99%. The procedure of training by the user.

The performance of the system of titration analyzers of the type AK-7516 check purge tube gazopodvodyaschey Converter, slowly exhaling the air (for breathing) and achieving the deflection of the indicator of a pH meter by 0.5 to 0.65, where the maximum value on the scale. The value obtained indicates the suitability of the solutions in the measurement cell. With a smaller deflection of the indicator solutions are replaced in accordance with the instructions.

5.3.3 In accordance with the instruction, determine an amendment in the reference experiment (SDS) and enter it in the microprocessor. The determination is carried out on the same modes of degassing and analyzing that sample, with the introduction of the compensator mass of the sample specified in the instructions.

If the value of PKO for more than 6·10% batch of crucibles and annealed at a residual pressure of not more of 6.65 PA (5·10mm Hg.St.) and a temperature of 1900−2000 °C for 4−5 h. After cooling, the crucibles with the pressure to room temperature and extraction should be stored in a desiccator or plastic bags filled with dry nitrogen.

The average value of FFP administered in a storage device of the analyzer in the reactive value with a minus sign in accordance with the instructions.

5.3.4 Calibrating analyzers

Analyzers graduate using. The procedure of calibration is in accordance with the instructions. The coefficient of graduation is introduced into the microprocessor.

Requirements for WITH — 3.2.

5.4 analysis

The procedure for determining the mass fraction of oxygen in the analyzed samples must comply with the user manual for analyzer specific type («Work»).

To determine the mass fraction of oxygen in titanium and titanium alloys are used in idle tub that is loaded directly into the crucible at the stage of its installation on the lower electrode furnace before decontamination.

Optimal working regimes, the mass of samples and composition of the «blank» baths are based on the types of analyzers used shall be as specified in table 2.


Table 2

Analyzer type	The mass of sample, g	Composition «blank» baths* (mass ratio)	Dilution (ratio)**	The temperature of analysis, °C	The time of extraction,	The degassing temperature, °C	Degassing time, with
RO-116	0,2−0,3	15:1	1:10	2200−2250	20−25	2500−2600	25−30
02A-2002, AK-7516	Of 0.05−0.10
______________ * In the numerator specified weight of Nickel or steel, the denominator is the mass of tin (relative). ** In the numerator specified mass of test sample, the denominator is the mass of «blank» baths (relative)
Note — In the preparation of «blank» bath and diluted the deviation from the above mass ratio, but not more than 15%.

5.5 processing of the results

5.5.1 Results of the determination are issued automatically displayed on the display of digital voltmeter or printed on the ribbon: for analyzers of the types of RO-116 and AK-7516 — percentage analyzers of the type 02A-2002 — in parts per million (million).

5.5.2 discrepancies in the results must not exceed the values given in table 3, at confidence probability of 0.95.


Table 3 — Norms of permissible differences

The mass fraction of oxygen, %					The absolute allowable difference, %
for convergence	for reproducibility
From 0.020 to 0.040 incl.					0,013	0,016
SV.	0,040	«	0,060	«	0,016	0,019
«	0,060	«	0,090	«	0,020	0,024
«	0,090	«	0,120	«	0,024	0,029
«	0,120	«	0,150	«	0,030	0,036
«	0,15	«	0,20	«	0,04	0,05
«	0,20	«	0,30	«	0,05	0,06
«	0,30	«	0,40	«	0,06	0,07
«	0,40	«	0,50	«	0,07	0,08

Annex a (informational).BIBLIOGRAPHY

APPENDIX A
(informational)

[1]	THAT 48−4803−90−80	Crucibles, graphite (Novocherkassk electrode plant, Novocherkassk, Rostov region)
[2]	THAT 6−21−39−79	Nitrogen calibration (Balashikha oxygen plant, Balashikha, Moscow region).
[3]	THAT 6−21−81−78	The calibration gas mixture of carbon monoxide with nitrogen (Balashikha oxygen plant, Moscow region, Balashikha, Moscow region).
[4]	THAT 6−09−3880−75	Magnesium rate (Berezniki chemical plant, Berezniki, Perm region).