GOST 9853.5-96

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  ГОСТ 9853.5-96

GOST 9853.5−96 Titan spongy. Methods for determination of oxygen

GOST 9853.5−96

Group B59

INTERSTATE STANDARD

TITANIUM SPONGE

Methods for determination of oxygen

Sponge titanium.
Methods for determination of oxygen

ISS 77.120
AXTU 1709

Date of introduction 2000−07−01

Preface

1 DEVELOPED by the Interstate technical Committee for standardization MTK 105, Ukrainian research and design Institute of titanium

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

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 9 dated April 12, 1996)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated 19 October 1999 No. 353-St inter-state standard GOST 9853.5−96 introduced directly as state standard of the Russian Federation from July 1, 2000.

4 REPLACE GOST 9853.5−79

1 Scope

This standard establishes the procedure for determination of oxygen in spongy titanium according to GOST 17746 by neutron activation (when the mass fraction of oxygen from 0.02% to 0.12%) and by the method of reductive melting in a current of inert carrier gas (when mass fraction of oxygen, from 0.005% to 0.36%).

The technique of neutron activation based on the use of nuclear reactions On(, ) N. The oxygen content is determined by comparing the activity of the sample with the activity of a control sample.

The method of reductive melting in a current of inert carrier gas based on the reductive melting of the samples under a stream of nitrogen or argon with subsequent determination of the evolved carbon dioxide by measuring the absorption in the infrared region of the spectrum.

2 Normative references

The present standard features references to the following standards:

GOST 8.315−97 State system for ensuring the uniformity of measurements. The standard samples. The main provisions, the order of development, certification, approval, registration and application

GOST 61−75 acetic Acid. Specifications

GOST 2179−75 Wire from Nickel and siliceous Nickel. Specifications

GOST 2603−79 Acetone. Specifications

GOST 2789−73 surface Roughness. Parameters and characteristics

GOST 3118−77 hydrochloric Acid. Specifications

GOST 4461−77 nitric Acid. Specifications

GOST 5556−81 Wool medical hygroscopic. Specifications

GOST 9293−74 Nitrogen gaseous and liquid. Specifications

GOST 10157−79 Argon gaseous and liquid. Specifications

GOST 17433−80 Industrial purity. Compressed air. Classes of contamination

GOST 17746−96 spongy Titanium. Specifications

GOST 18300−87 ethyl rectified technical. Specifications

GOST 20288−74 Carbon tetrachloride. Specifications

GOST 23780−96 spongy Titanium. Methods of sampling and sample preparation

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 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.

3 General requirements

3.1 General requirements for methods of analysis GOST 25086.

3.2 Selection and preparation of samples is carried out according to GOST 23780.

3.3 Mass fraction of oxygen is determined: by the method of reductive melting in a stream of inert carrier gas in two batches; using the method of neutron activation for the two measurements in one sample.

4 Neutron-activation method

4.1 measuring instruments and auxiliary devices

Setup for determination of oxygen by neutron generator of 14 MeV with a flux of at least 10on natural hair./s

Control samples of polymethylmethacrylate (CHO)or other oxygen-containing substances with a constant and known stoichiometric composition. In the material of the control sample should be absent impurities fluorine, boron, plutonium and uranium.

To reduce mechanical wear of the control sample and the transport system is allowed to place the samples in the transport containers. The geometric dimensions of the samples should correspond to the inner sizes of used shipping containers. Transport containers are made of a material with a low oxygen content. The mass fraction of oxygen , %, in the material of the shipping container shall not exceed the values calculated according to the formula

, (1)

where  — minimum mass of test sample, g;

 — weight of the shipping container,

Material of the shipping container should not contain impurities that prevent the determination of oxygen (fluorine, boron, plutonium, uranium).

The external dimensions of the transport containers must match the size of the transport system of the installation.

Scales with a weighing error of ±0.01 g according to GOST 24104.

Acetone according to GOST 2603.

Ethanol (ethyl alcohol) rectified technical GOST 18300.

Medical absorbent cotton wool GOST 5556.

Baptiste GOST 29298.

4.2 preparation for measurement

4.2.1 Preparation of samples for analysis

The sample for determining the oxygen made from the sample to determine the hardness in the form of a cylinder with geometric dimensions corresponding to the transport system. The roughness parameter of the machined surface according to GOST 2789 — not more than 2.5 µm.

The sample is weighed with an accuracy of ±0.01 g, wipe with acetone, ethanol and dried in air.

4.2.2 Preparation instrument to the analysis

Preparation instrument to the analysis carried out in accordance with the manual installer for the determination of oxygen.

4.2.3 Measure the natural background in the channels of the sample and the monitor for a time equal to the measurement time.

4.3 measurements

The analyzed sample is loaded into the transport system installation, specify the exposure time and measuring the number of cycles of irradiation-measurement and start the analysis program. After executing the analysis program to record the number of registered pulses from a test sample and a control sample or monitor .

The exposure time, dimensions, and number of cycles are determined by the characteristics of used test equipment, oxygen.

Carrying out of measurements and calibrations carried out in accordance with the technical documentation for the installation for the determination of oxygen.

4.4 Processing of measurement results

4.4.1 Mass fraction of oxygen in the sample when using dual channel setup calculated by the formula

; , (2)

where ,  — the number of registered pulses from a test sample and a control sample minus the corresponding background;

- calibration coefficient, g;

 — mass of test portion, g;

- the number of registered pulses from a sample for monitoring in the monitor net of related background;

- the number of registered pulses from a control sample for monitoring in the channel of the sample minus the corresponding background;

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

.

4.4.2 Mass fraction of oxygen in the sample when using a monitor, recording directly the neutron flux, calculated by the formula

; , (3)

where  — the number of registered pulses from the monitor minus the background.

Note — When using the monitor, recording directly the neutron flux, it is necessary to take into account the time span of the sample from the position of the irradiation position of the measurement. In this case, is the following:

, (4)

where  — time of flight;

 — natural background in the channel of the sample.

4.4.3 In the case of transport containers mass fraction of oxygen is calculated by the formula

, (5)

where ,  — mass fraction of oxygen in the material of the transport container and in air, %;

,  — the volume transport of the container and of the sample, cm;

- vehicle mass of container, g;

is the air density equal to 1.2·10g/s

m.

4.5 Permissible error of measurement

4.5.1 allowable Absolute differences of two measurements (at confidence probability of 0.95) shall not exceed the values given in table 1.


Table 1

Percentage

4.5.2 validation of the results of the analysis carried out according to standard sample of titanium metal GEO N 2024. Allowed to use other state standard samples of composition of titanium and titanium alloys with a certified mass fraction of oxygen from 0.02% to 0.12%.

Mass fraction of oxygen in the standard sample, find two definitions.

The results of the analysis are considered valid if the difference between measurements does not exceed the values given in table 1 for the certified oxygen content in the standard sample, and the average value of the result of analysis differs from the certified oxygen content in the standard sample is not more than the value of 0.71 permitted discrepancy between the results of the analysis.

4.5.3 Method is used when differences in assessing the quality of titanium sponge.

5 the Method of reductive melting in a current of inert carrier gas

5.1 measuring instruments and auxiliary devices

Oxygen analyzer RO-116 «LEKO» or similar device, equipped with a microwave pulse heating and infrared sensor.

Graphite crucibles recommended by the manufacturer of the analyzer, or similar in size and material properties.

Nickel (wire) according to GOST 2179-section 0.5−1.0 mm slices with a length of 2−5 mm. allowed the use of sheet Nickel, is cut into pieces weighing up to 0.05 g.

Nitrogen gas according to GOST 9293, input pressure swing line 0,294 MPa.

Argon gas according to GOST 10157, input pressure swing line 0,294 MPa.

Compressed air input pressure in swing line 0,294 MPa according to GOST 17433.

Tin granulated according to the current normative document.

Ethanol (ethyl alcohol) rectified technical GOST 18300.

Carbon tetrachloride according to GOST 20288.

Acetic acid according to GOST 61.

Nitric acid according to GOST 4461.

Hydrochloric acid according to GOST 3118.

Standard samples of the composition of titanium GOST 8.315.

5.2 preparation for measurement

5.2.1 Preparation of samples for analysis

Analyzing the sample produce turning test ingot obtained according to GOST 23780, in the form of a cylinder. The sample mass is not more than 0.1 g When making the samples of titanium we accept the following modes of machining: linear cutting speed of 0.69−17,80 m/min, feed of 0.015−0.10 mm/Rev. The roughness parameter of the surface of analyzed samples should not exceed 2.5 µm according to GOST 2789. Are not allowed metal cooling emulsions. Cutters and cartridge previously degreased by washing in carbon tetrachloride. Analyze the sample after the turning process, washed with ethanol, dried and stored in a desiccator or in a closed box.

5.2.2 Preparation of baths analysis

The surface of the Nickel before use, washed in ethanol and dried at room temperature. In the presence of an oxide film on the surface of the Nickel prior etching it into preheated to a temperature of 333 K of a mixture of acetic, nitric and hydrochloric acids, taken in the ratio 3:1:0,5. After etching, the Nickel washed with water, then with ethanol and dried at room temperature. The thus prepared Nickel stored in a desiccator and loaded into the analyzer with the help of forceps and spatula.

5.2.3 Preparation instrument to the analysis

Preparation for work and inclusion of the analyzer is carried out according to the instruction manual.

Set the following parameters of the process:

the degassing time is 20−30 s,

analysis time is 15−25 s,

cooling time — 20

the temperature of degassing — (2323−2573),

temperature analysis (2173−2323) K.

The other working parameters set according to the technical description of the instrument.

The working gas using nitrogen. Allowed the use of argon.

5.2.4 Preparation of a graphite crucible for analysis

For conducting the annealing crucible press twice the button «Loader Control» of the device, open the reactor and mounted on the lower current lead graphite crucible open end facing up. The operation mode switch is put to position «Manual». Press «Analyse». After completion of the degassing, press the button «Reset» and then press the «Loader Control». Tweezers removed from the bottom of the current lead orderativan crucible and placed in a clean dry closed container (storage is allowed within 2−3 days).

When working with standardized crucibles who have undergone the annealing in the factory, allowed an exception described in this section of the procedure.

5.3 procedures for measuring

5.3.1 Prior to analysis spend control experience. To do this, press the «Manual Weight», «0», «1», «Enter» artificially injected mass value corresponding to a weighed test portion (0.1 g). Press «Control Loader», a pellet of tin weighing about 0.2 g is placed in the open gateway of the furnace.

In the pre-orderativan crucible placed Nickel weighing 1 g. the Mass ratio of titanium-Nickel is 1:10. Permissible deviation from the specified ratio of no more than 15%.

Press «Control Loader» and place the Nickel crucible with the lower current lead. Set the operation mode switch in position «Automatic», then press «Analyse».

After closing the furnace, the formation and degassing of Nickel bath in the tub is automatically reset pellet tin. The value of the watch experience read on the scoreboard and pressing the «Blank» is introduced into the calculation device of the analyzer.

5.3.2 Sample standard sample prepared in accordance with 5.2.1 shall be weighed and the «Enter» key to transmit the obtained value of the mass (about 0.1 g) in the analysis device.

Press the button «Loader Control», a portion of the sample and the pellet tin with a mass of about 0.2 g is placed in the open gateway of the furnace pulse heating. Then do as described in 5.3.1.

The amount of excreted carbon dioxide measured by IR detector. The obtained value of oxygen content in the standard sample is automatically entered in the estimated device analyzer.

The oxygen content in the standard sample determined in five batches.

5.3.3 Sample the sample weighing about 0.1 g is weighed and the «Enter» key to transmit the value obtained in the calculation device of the analyzer. Then do as described in 5.3.1.

The value of the mass fraction of oxygen in the analyzed sample, expressed as a percentage, is read from the display unit.

5.4 the Processing of the measurement results

Processing of measurements made by the device automatically. The result of analysis in percent is displayed on the scoreboard.

5.5 Permissible error of measurement

5.5.1 the discrepancy between the measurement results and analysis results (at a confidence probability of 0.95) shall not exceed the values given in table 2.


Table 2

Percentage

5.5.2 accuracy Control of measurement results carried out according to standard sample in accordance with GOST 25086.

6 qualifications

To perform analysis allowed the analyst qualification not less than 4th level.