GOST R ISO 10280-2010

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  ГОСТ Р ИСО 10280-2010

GOST R ISO 10280−2010 Steel and cast iron. The determination of titanium. Spectrophotometric method with the use of diantipyrylmethane

GOST R ISO 10280−2010

Group B39

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

STEEL AND CAST IRON

The determination of titanium. Spectrophotometric method with the use of diantipyrylmethane

Steel and iron. Determination of titanium content. Diantipyrylmethane spectrophotometric method

OKS 77.080.01
AXTU 0709

Date of introduction 2012−03−01

Preface

The objectives and principles of standardization in the Russian Federation established by the Federal law of 27 December 2002 N 184-FZ «On technical regulation», and rules for the application of national standards of the Russian Federation — GOST R 1.0−2004 «Standardization in the Russian Federation. The main provisions"

Data on standard

1 PREPARED by FSUE «tsniichermet im. I. P. Bardina», Technical Committee for standardization TC 145 «monitoring Methods of steel products» on the basis of authentic translation into the Russian language of the standard referred to in paragraph 4

2 SUBMITTED by the Technical Committee for standardization TC 145 «monitoring Methods of steel products"

3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology of December 21, 2010 N 912-St

4 this standard is identical to international standard ISO 10280:1991* «Steel and cast iron. The determination of titanium. Spectrophotometric method with the use of diantipyrylmethane» (ISO 10280:1991 «Steel and iron — Determination of titanium content — Diantipyrylmethane spectrophotometric method»).
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* Access to international and foreign documents can be obtained by clicking on the link, here and hereafter. — Note the manufacturer’s database.

In applying this standard it is recommended to use instead of the referenced international standards corresponding national standards of the Russian Federation, details of which are given in the help app YES

5 INTRODUCED FOR THE FIRST TIME


Information about the changes to this standard is published in the annually issued reference index «National standards», and the text amendments and amendments to published monthly the information sign «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in a monthly information index «National standards».

Relevant information, notification and lyrics are also posted in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet

1 Scope

This standard specifies a spectrophotometric method with the use of diantipyrylmethane to determine the content of titanium in steel and iron.

The method is applicable for determining a mass fraction of titanium in the range from 0.002% to 0,800%.

2 Normative references

This standard uses the regulatory references to the following international standards:

ISO 377−2:1989* Selection and preparation of samples for testing of wrought steels. Part 2. Samples for determination of chemical composition (ISO 377−2:1989 Selection and preparation of samples and test pieces of wrought steels; part 2: samples for the determination of the chemical composition)
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* Valid ISO 14284:1996 «Steel and cast iron. Selection and preparation of samples for the determination of chemical composition».


ISO 385−1:1984* laboratory Glassware. Burette. Part 1. General requirements (ISO 385−1:1984, Laboratory glassware — Burettes — Part 1: General requirements)
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* Valid ISO 385:2005 «laboratory Glassware glass. Burettes».


ISO 648:1977* laboratory Glassware. Pipettes with one mark (ISO 648:1977, Laboratory glassware — One-mark pipettes)
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* Valid ISO 648:2008 «laboratory Glassware glass. Pipette with one mark».


ISO 1042:1998 laboratory Glassware. Flasks volumetric with one mark (ISO 1042:1983, Laboratory glassware — One-mark volumetric flasks)

ISO 5725:1986* Precision of test methods. Determination of repeatability and reproducibility of a standard method by interlaboratory tests (ISO 5725:1986 Precision of test methods; Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests)
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Please refer to ISO 5725−1:1994 «Accuracy (trueness and precision) of methods and measurement results. Part 1. General principles and definition»,

ISO 5725−2:1994 «Accuracy (trueness and precision) of methods and measurement results. Part 2. The basic method for the determination of repeatability and reproducibility of a standard measurement method»,

ISO 5725−3:1994 «Accuracy (trueness and precision) of methods and measurement results. Part 3. Intermediate indicators the precision of a standard measurement method»,

ISO 5725−4:1994 «Accuracy (trueness and precision) of methods and measurement results. Part 4. Basic methods of determining the correctness of a standard measurement method»,

ISO 5725−5:1994 «Accuracy (trueness and precision) of methods and measurement results. Part 5. Alternative methods for determining the precision of a standard measurement method»,

ISO 5725−6:1994 «Accuracy (trueness and precision) of methods and measurement results. Part 6. The use of precision values in practice».

3 the essence of the method

The method is based on dissolving an analytical sample in hydrochloric, nitric and sulphuric acids.

Zaplavnoye insoluble residue with acid potassium sulphate as flux.

The formation of yellow complex with 4,4-diantipyrylmethane.

Spectrophotometric measurements of the colored complex at a wavelength of about 385 nm.

4 Reagents

4.1 Iron of high purity, containing less than 2 µg Ti/g.

4.2 Acidic potassium sulfate (KHSO).

4.3 sodium Carbonate (NaCO), anhydrous.

4.4 Hydrochloric acid density of 1.19 g/cm.

4.5 Nitric acid with density of 1.40 g/cm.

4.6 Hydrofluoric acid, density of 1.15 g/cm.

4.7 Hydrochloric acid density of 1.19 g/cm, diluted 1:1.

4.8 Hydrochloric acid density of 1.19 g/cm, diluted 1:3.

4.9 Sulphuric acid, density 1.84 g/cm, diluted 1:1.

4.10 Tartaric acid solution with a density of 100 g/DM.

4.11 Ascorbic acid, solution, density of 100 g/DM.

The solution is prepared immediately before use.

4.12 ammonium Oxalate, solution

Dissolve 6 g of monohydrate of ammonium oxalate [(COONH)·HO] in water and dilute to 200 cm.

4.13 Iron, solution, 12.5 g/DM

Dissolve 1.25 g of iron (4.1) in 10 cmof hydrochloric acid (4.7) with gentle heating, add 5 cmof nitric acid (4.5) and boil until, until the solution volume is reduced to approximately 10 cm. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cmwith a single label, dilute to the mark with water and mix.

4.14 the Solution of the blank experience

A solution of the blank experience in parallel with the determination of titanium using the same quantities of reagents, which were taken for the determination of titanium in the sample, but not in the gland. You must follow the procedure in 7.3.1 and 7.3.2, the solution was diluted with water to 100 cm.

4.15 Solution diantipyrylmethane

Dissolve 4 g of monohydrate — 4,4' methylene-bis (2,3-dimethyl-1-phenyl-5-pyrazolone), CHON·HOh, (diantipyrylmethane) in 20 cmof hydrochloric acid (4.7) and dilute with water to 100 cm.

4.16 Standard solution of titanium

4.16.1 Basic solution containing 1 g/DMof titanium, is prepared as follows. The weight 0,500 g of high-purity titanium metal with a purity more than 99.9% are weighed with accuracy to 0.0001 g and placed in a beaker with a capacity of 300 cm. Add 180 cmsulfuric acid density 1.84 g/cm, diluted 1:3, cover with a watch glass, gently heated until complete dissolution of the metal, is oxidized with nitric acid (4.5) added dropwise. The solution was cooled and transferred to volumetric flask with a capacity of 500 cm, is diluted to the mark with water and mix.

1 cmof this solution contains 1.0 mg of titanium.

4.16.2 Standard solution containing 50 mg Ti/l, is prepared as follows. 10.0 cmbasic solution of titanium (4.16.1) is placed in a volumetric flask with a capacity of 200 cm, is diluted to the mark with water and mix.

The solution is prepared immediately before use.

1 cmof this solution contains 50 micrograms of titanium.

Note — Unless otherwise specified, use reagents of the established analytical purity and distilled water, further purified by distillation or other means.

5 Instrument

All volumetric glassware should be class A in accordance with ISO 385−1, or ISO 648 ISO 1042.

Usual laboratory apparatus, and equipment listed in 5.1, 5.2.

5.1 Crucible of platinum or platinum alloy of gold with a capacity of 30 cm.

5.2 Spectrophotometer must be capable of measuring optical density at a wavelength of 385 nm.

The wavelength set must be performed with accuracy of ±2 nm or less. When measuring values of optical density from 0.05 to 0.85 should ensure the repeatability of the analytical signal with an accuracy of ±0,003 or less.

6 Sampling

Sampling carried out in accordance with ISO 14284.

7 analysis

7.1 Analytical linkage

Weighed analytical sample with an accuracy of 0.0005 g in accordance with the estimated mass proportions of titanium:

a) the content of titanium in the range of mass fraction from 0.002% to 0.125% suspension of 1.00 g;

b) the content of titanium in the range of mass fraction from 0,1255% to 0.80% suspension of 0.50 g.

7.2 Blank

Parallel to the determination of titanium in the sample, the same procedure, carry out blank using the same quantity of all reagents and the cuvette to measure the optical density, applying as an analytical sample of the weighted equivalent amount of iron (4.1).

7.3 Determination of titanium

7.3.1 Dissolution of the analytical sample

Put a portion (7.1) in a beaker with a capacity of 250 cm, add 20 cmof hydrochloric acid (4.4), cover the beaker watch glass and dissolved at a temperature of from 70 °C to 90 °C until the termination of the dissolution. Add 5 cmof nitric acid (4.5) and evaporated until then, until the solution volume reaches approximately 10 cm.

The solution was cooled, added to 20 cmof sulphuric acid (4.9) and evaporated until the appearance of white fumes of sulfur trioxide (SO). Just before the vapor (SO) leads to the formation of solid particles of salts, which can lead to the release of solution from the glass, so the heat it carefully. After the appearance of the vapor SOstands out a mixture of solid salts at high temperatures, the liquid can quickly evaporate. Excessive evaporation must be avoided, in particular, in the case of the analysis of chrome-alloy as precipitated salts of chromium are difficult to re-dissolve.

After cooling the solution, add 20 cmof hydrochloric acid (4.8) and gently heated to re-dissolve the salts.

The resulting solution was filtered through ashless filter paper with medium density and washed with hot water, washed again in 10 cmof hydrochloric acid (4.7), and then washed in hot water. The filtrate is saved.

7.3.2 the Processing of the insoluble residue

The filter paper with residue was placed in a crucible (5.7), dried and incinerated at such a low temperature as possible until all carbon-containing substances are not removed, then kept at a temperature of approximately 700 °C for about 15 min. Cool, add a few drops of sulfuric acid (4.9) and 2 cmhydrofluoric acid (4.6), evaporated to dry residue and calcined at a temperature of 700 °C.

Note — For analytical batches containing tungsten, the processing is carried out in accordance with section 9.


Calcined residue is fused with 1.0 g acid potassium sulphate (4.2) on a Bunsen burner and cooled. The smelt is dissolved by heating in 10 cmof a solution of tartaric acid (4.10) and add to the main filtrate. Carry everything in a measuring flask with a capacity of 100 cmor 200 cmin accordance with table 1, dilute to the mark with water and mix.


Table 1

7.3.3 the development of the painting

Put two aliquote part of the solution in accordance with table 1 in separate volumetric flasks with a capacity of 50 cmto prepare the analyzed solution and a reference solution. Introduce supplements using burettes or pipettes, stirring the solution after each Supplement.

a) Analyze the solution:

— solution of iron (4.13), if necessary (table 1);

— solution blanks experience (4.14), if necessary (table 1);

— 20 mmsolution of ammonium oxalate (4.12);

— 6.0 cmof hydrochloric acid (4.7);

— 8.0 cmof ascorbic acid solution (4.11), after adding the necessary exposure for 5 min;

— 10.0 cmsolution diantipyrylmethane (4.15).

b) Solution comparison:

— solution of iron (4.13), if necessary (table 1);

— solution blanks experience (4.14), if necessary (table 1);

— 20 mmsolution of ammonium oxalate (4.12);

— 8.0 cmof hydrochloric acid (4.7);

— 8.0 cmof ascorbic acid solution (4.11), after adding the necessary exposure for 5 min.

Solutions a) and b) dilute to the mark with water and mix. The solutions stand 30 min at a temperature of from 20 °C to 30 °C. If the temperature is in the range from 15 °C to 20 °C, it is necessary to increase the exposure time up to 60 min.

7.3.4 Spectrophotometric measurements

Set the wavelength on the spectrophotometer (5.2) 385 nm.

Placed optical cuvette containing water in the spectrometer and set the instrument to zero absorbance. Choose a cell size appropriate to cover the desired range (table 1). If you change the size of the cell, you must re-set the spectrometer to zero absorbance, using a new cuvette.

Measure the optical density of colored solutions and solutions of comparison for the test sample and the blank solution experience.

For each pair of readings of the values of absorption determine the optical density of the analyzed solution by subtracting the value of absorbance of solution a comparison of the magnitude of the total absorption.

7.4 Construction of calibration curve

7.4.1 Preparation of calibration mixtures

Sample of iron (4.1) weighing 1,000 g, weighed with accuracy to 0.001 g, placed in a series of glasses with a capacity of 250 cm. Add the volume of a standard solution of titanium (4.16.2) in table 2 and then conducting analysis 7.3.1.


Table 2

Then add 10 cmof hydrochloric acid (4.7), 1.0 g of acidic potassium sulfate (4.2) and 10 cmof tartaric acid solution (4.10) to each filtrate, mixed well until dissolved. The solution was then cooled, placed in a series of volumetric flasks with a capacity of 100 cm, is diluted to the mark with water and mix.

Aliquot part of a volume of 10.0 cmof each calibration solution is placed in a separate volumetric flask with a capacity of 50 cmand add the reagents for the full manifestation of color, as indicated in 7.3.3.

No need to add the solution of iron (4.13) and the blank solution experience (4.14).

Note — there is No need to prepare a solution of comparison for each calibration solution. Prepare the reference solution only for a zero of a solution and is measured relative to this solution, the optical density of each calibration solution.

7.4.2 Spectrophotometric measurements

Carry out the spectrophotometric measurements of each solution according to 7.3.4. For alleged mass fraction of titanium to 0.050% perform measurements in a cell with optical path length 2 cm For the rest of the solutions measurements are performed in a cuvette with an optical path length of 1 cm.

7.4.3 Construction of calibration curve

On the found values of optical density of the solutions and their corresponding titanium concentration in µg/cmbuild calibration graphs.

8 Processing of results

8.1 Method of calculation

The values of optical density of colored solutions analyzed (7.3.4) is found using the calibration graph (7.4.3), the concentration of titanium in micrograms/cm.

Mass fraction of titanium , %, is calculated by the formula

where is the concentration of titanium in the solution of the blank experience (adjusted for its solution), µg/cm;

concentration of titanium in the sample solution (adjusted to reference solution), µg/cm;

 — the volume of the analyzed solution (table 1), cm;

 — volume aliquoting part (table 1), cm;

 — the volume of colour solution (7.3.3) cm;

is the mass of analytical portion (7.1),

8.2 Precision

Experimental verification of this method was performed in 17 laboratories for nine levels of titanium, and each laboratory conducted three definitions for each content of titanium (notes 1 and 2).

Used the samples given in table A. 1.

The results obtained were processed in accordance with ISO 5725.

The obtained data showed a logarithmic correlation between the titanium content, repeatability (convergence) and reproducibility and test results (note 3) as specified in table 3.


Table 3

A graphical representation of the accuracy characteristics are given in the Appendix V.

Notes

1 Two of the three definitions was performed in the conditions of repeatability (convergence), as specified in ISO 5725, i.e., one operator, same apparatus, identical conditions of measurement, the same calibration curve within the minimum period of time.

2 the Third dimension was performed at different time periods (different days) by the same operator (see note 3) using the same equipment, but with a new calibration schedule.

3 Based on the obtained results, the first day repeatability (convergence) and reproducibility were calculated according to ISO 5725. From the first result obtained on the first day, and the result obtained on the second day, calculated the interlaboratory reproducibility ().

9 Special case

Decomposition of the analytical sample, containing tungsten, insoluble residue, obtained after processing it with sulfuric and hydrofluoric acids, drying and calcination at 700 °C, is fused with 5 g of sodium carbonate (4.3) at 950 °C. the Cooled melt is dissolved in 200 cmof water. Heat the solution to boiling and filtered through filter paper medium density, then washed the filter with hot water, the filtrate discarded. The filter with precipitate was placed in a crucible (5.1), dried and calcined at a temperature of 700 °C.

Continued operation 7.3.2, beginning with the words, «Calcined residue is fused with 1.0 g acid potassium sulphate (4.2)…» to the end.

Perform a separate blank (7.2) and prepare a separate blank solution experience (4.14).

Note — the Specified operation is performed for the effect of contamination of the reagent.

10 test report

The test report must contain:

— all information necessary for sample identification, the laboratory and date of analysis;

— a link to the method given in the standard;

the results of the tests and methods of processing;

— any unusual phenomena occurring in the process definition;

— any additional operations that may affect the test results.

Annex a (informative). Additional information about the international experiment

Appendix A
(reference)

Table 3 obtained from the results of the international experiment performed in eight steel samples and on one sample of pig iron in the eight countries in 17 laboratories.

Graphic image data of the precision are given in Appendix B.

Samples used for tests are given in table A. 1.


Table A. 1

Annex b (informative). Graphical representation of precision data

The App
(reference)

Figure B. 1 Is a Logarithmic dependence between the mass fractions of titanium, repeatability and reproducibility

Figure B. 1 Is a Logarithmic dependence between the mass fractions of the Titan (), repeatability (), and repeatability (and ):

;

;

,

where  — the average value of the content of the titanium obtained in one day, %;

 — average levels of Titan, obtained on different days, %

App YES (reference). Information about the compliance of the referenced international standards reference the national standards of the Russian Federation (and acting in this capacity inter-state standards)

App YES
(reference)

Table YES.1