GOST R ISO 10153-2011

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  ГОСТ Р ИСО 10153-2011

GOST R ISO 10153−2011 Steel. Determination of the boron content. Spectrophotometric method with the use of curcumin

GOST R ISO 10153−2011

Group B39

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

STEEL

Determination of the boron content.
Spectrophotometric method with the use of curcumin

Steel. Determination of boron content. Curcumin spectrophotometric method

OKS 77.080.20
AXTU 0709

Date of introduction 2012−08−01

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 AND SUBMITTED by the 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 3

2 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology dated 10 November 2011 N 538-St

3 this standard is identical to international standard ISO 10153:1997* «Steel. Determination of the boron content. Spectrophotometric method with the use of curcumin» (ISO 10153:1997 «Steel — Determination of boron content — Curcumin spectrophotometric method»).
________________
* Access to international and foreign documents mentioned here and below, you can get a link on the website shop.cntd.ru. — 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 and interstate standards, details of which are given in Appendix YES

4 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 changes and amendments — in monthly indexes published information «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 curcumin for the determination of boron in steel.

The method is applicable for determining the mass fraction of boron in unalloyed steels in the range of from 0.0001% to 0.0005% of other types of steel from 0.0005% to 0,012%.

2 Normative references

This standard uses the regulatory references to the following international standards:
_______________
For dated references, only use the specified edition of the standard. In the case of undated references, the latest edition of the standard, including all revisions and amendments.


ISO 385−1:1984 laboratory Glassware glass. Burette. Part 1. General requirements (ISO 385−1:1984, Laboratory glassware — Burettes — Part 1: General requirements)
_______________
The standard ISO 385:2005 laboratory Glassware glass. Burettes (ISO 385:2005, Laboratory glassware — Burettes).


ISO 648:1977 laboratory Glassware glass. Pipettes with one mark (ISO 648:1977, Laboratory glassware — One-mark pipettes)
_______________
Valid ISO 648:2008 laboratory Glassware glass. Pipettes with one mark (ISO 648:2008, Laboratory glassware — Single-volume pipettes).


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

ISO 3696:1987 Water for laboratory analysis. Technical requirements and test methods (ISO 3696:1987, Water for analytical laboratory use — Specification and test methods)

ISO 5725−1:1994 Accuracy (trueness and precision) of methods and measurement results. Part 1. General principles and definitions [ISO 5725−1:1994, Accuracy (trueness and precision) of measurement methods and results — Part 1: General principles and definitions]

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 5725−2:1994, Accuracy (trueness and precision) of measurement methods and results — Part 2: 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 5725−3:1994, Accuracy (trueness and precision) of measurement methods and results — Part 3: Intermediate measures of the precision of a standard measurement method]

ISO 14284:1996 Steel and iron. Selection and preparation of samples for determination of chemical composition (ISO 14284:1996, Steel and iron — Sampling and preparation of samples for the determination of chemical composition)

3 the essence of the method

This method is based on dissolving a measured sample in hydrochloric and nitric acids and the decomposition of boron compounds (nitrides, etc.) of phosphoric and sulphuric acids at a temperature of 290 °C with subsequent formation of colored complex compounds of boric acid and curcumin in the environment acetate buffer solution.

Spectrophotometric measurement performed at a wavelength of 543 nm.

4 Reagents

In the analysis, unless otherwise stated, use only reagents established analytical purity with a very low boron content, and only water the 2nd degree of purity according to ISO 3696.

4.1 Pure iron containing no boron or containing a known residual amount of boron.

4.2 Hipofosfit sodium monohydrate (NaHPO·HO).

4.3 Hydrochloric acid of 1.19 g/cm.

4.4 Nitric acid, of 1.40 g/cm.

4.5 Sulphuric acid, 1.84 g/cm.

4.6 Phosphoric acid of 1.71 g/cm.

4.7 Acetic acid, not containing aldehyde (1.05 g/cm)

To check the acetic acid in the presence of the aldehyde is placed 20 cmof acetic acid (of 1.05 cm) and 1 cmof solution of potassium permanganate (1 g/DM) in a beaker with a capacity of 50 cm. In the absence of aldehyde the original violet color of the potassium permanganate solution is retained; otherwise, the solution after 15 minutes is colored in brown color.

4.8 the Mixture of acetic and sulfuric acids

In a flask containing acetic acid (4.7), add small portions of equal volume of sulphuric acid (4.5) with vigorous stirring and continuing cooling the flask under running cold water.

4.9 Acetate buffer solution

Dissolve 225 g of ammonium acetate in 400 cmof water. Add 300 cmof acetic acid (4.7). The resulting solution was filtered in a polypropylene volumetric flask with a capacity of 1000 cm, is diluted to the mark with water and mix.

4.10 sodium Fluoride, solution 40 g/DM

The solution was stored in a polypropylene container.

4.11 Boron, standard solution

4.11.1 Basic solution with a concentration of boron of 0.1 g/DM

Weigh 0,2860 g of orthoboric acid (HIN) with an accuracy of 0.0001 g. the sample is placed in a beaker with a capacity of 250 cm, and dissolved in 200 cmof water. The solution is transferred quantitatively into a measuring flask with one mark capacity of 500 cm. Dilute to the mark with water and mix. The solution was stored in a polypropylene container.

1 cmthis basic solution contains 0.10 mg of boron.

4.11.2 Standard solution with a concentration of boron of 0.002 g/DM

Transfer 20.0 cmbasic solution (4.11.1) volumetric flask with one mark capacity of 1000 cm. Dilute to the mark with water and mix. The solution was stored in a polypropylene container.

Prepare this standard solution just before use.

1 cmof this standard solution contains 2 µg of boron.

4.12 Curcumin, a solution of acetic acid, 1.25 g/DM

Weigh 0.125 g of curcumin, [SN(OH)WITHNSN=SNA]SN, is placed in a polypropylene or quartz vessel, add 60 cmof acetic acid (4.7) and mix. The vessel is heated in a water bath at 40 °C and stirred using a magnetic stirrer. After complete dissolution of curcumin, the cooled solution is transferred to a polypropylene volumetric flask with a capacity of 100 cm, is diluted acetic acid to the mark and mix.

5 Instrument

Storage solutions of boron it is impossible to use a glass dish, and only polypropylene or quartz, which was pre-washed with acetic acid (4.7), then with water and dried. All volumetric glassware should be class A in accordance with ISO 385−1, or ISO 648 ISO 1042.

Use conventional laboratory equipment and the following equipment.

5.1 Quartz beakers quartz lids with a capacity of 100 cm, an outer diameter of 51 mm and a height of 70 mm.

5.2 Polypropylene volumetric flasks with a capacity of 50 and 100 cm.

5.3 a Block of aluminum alloy with holes for the distribution of quartz glasses with a capacity of 100 cmfor warming them on a hot plate. A schematic representation of such blocks is given in Appendix A.

Note 1 — the size of the holes should match the size of existing quartz glasses.

5.4 Spectrophotometer, suitable for measurement of optical density at a wavelength of 543 nm in a cuvette with the thickness of the optical layer 2 see

6 Sampling

Sampling carried out in accordance with ISO 14284 or other suitable standards for steel.

The size of the individual chips used for analysis must be less than 1 mm.

7 analysis

7.1 Analytical linkage

Depending on the expected boron content is weighed with accuracy of 0.0002 g the following amount of sample mass :

a) when the mass fraction of boron from 0.0001% to 0,006% — 1.00 g;

b) when the mass fraction of boron from 0,006% to 0,012% — 0,50

For steel grades with a total mass fraction of Nickel and cobalt, more than 30% suspension of the studied samples should be approximately equal to 0,50

7.2 Blank

In parallel with the analysis of the investigated samples is carried out blank, instead of using sample test samples have the same mass weighed (7.1) pure iron (4.1). A blank experiment is performed under the same conditions using the same technique, the same amounts of all the necessary reagents and the same dilution solutions. Then measure the optical density of the blank solution experience and optical density of the solution comparison .

7.3 Determination of boron content

7.3.1 Preparation of test solution

The analytical sample (7.1) is placed in a quartz beaker (5.1) with a capacity of 100 cm. Add 10 cmof hydrochloric acid (4.3) and 5 cmof nitric acid (4.4), cover the beaker quartz cover (5.1) and leave the solution at ambient temperature (see note 2) until complete dissolution of the sample.

Note 2 — it is Very important to dissolve the sample at ambient temperature, to avoid possible losses of boron at elevated temperatures.


Then carefully add 10 cmof phosphoric acid (4.6) and 5 cmof sulphuric acid (4.5) and heated to form white fumes of sulfuric acid. For this purpose, the glass is placed in a hole of a block of aluminum alloy (5.3), which is mounted on the heater that the temperature 290 °C (see note 3) in solution.

Heating was continued for 30 minutes, carefully watching so that after the appearance of the white fumes of sulfuric acid the beaker was covered with a quartz lid. The solution is periodically stirred to dissolve any particles adhering to the walls of the glass.

Note 3 — the Temperature of (290±5) °C is controlled, grooving heater using a thermometer with scale from 0 °C to 350 °C, placed in a glass with a solution containing the same amounts of all the necessary to dissolve the reagents.


The glass is removed from the heater and cooled. Add small portions of 30 cmof water in syrupy solution is heated under stirring.

Warning — it is Very important cautiously add 30 cmof water into a syrupy solution. The solution is heated and may occur sudden release content that will lead to the loss of part of the investigated solution.

Cautiously add 5 cmof hydrochloric acid (4.3) and heated to boiling. Add 3 g of sodium hypophosphite (4.2) and gently boil the solution for 15 min.

The glass is removed from the heater and cooled. The solution was quantitatively transferred to a polypropylene volumetric flask (5.2) with a capacity of 50 cm, is diluted to the mark with water and mix.

7.3.2 Formation of colored complex

7.3.2.1 From the analyzed solution (7.3.1) is taken aliquot part with a volume of 1.0 cmand placed her in a polypropylene volumetric flask (5.2) with a capacity of 100 cm, pre-washed and dried.

7.3.2.2 Added to the flask following quantities of the following reagents, mix gently the solution after each addition, avoiding contact with the tube:

— 6.0 cmof a mixture of acetic and sulphuric acid (4.8), avoiding contact of the pipette with the neck and walls of the flask, and the solution is stirred;

— 6.0 cmof a solution of curcumin in acetic acid (4.12). The flask is stoppered and the solution was stirred. The mixture was left for 2 h 30 min for the full development of the color;

— 1.0 cmof phosphoric acid (4.6) was added for color stability of the complex, the flask is shaken and left for 30 min;

— 30,0 cmacetate buffer solution (4.9). The solution becomes orange. The flask is stoppered, shaken and left for 15 min.

7.3.3 preparation of the solution comparison

From the analyzed solution (7.3.1) is taken aliquot part with a volume of 1.0 cmand placed her in a polypropylene volumetric flask (5.2) with a capacity of 100 cm, which is pre-washed and dried. Add 0.2 cmof a solution of sodium fluoride (4.10) on the bottom of the flask.

This small volume of the solution carefully mix and leave for 1 hour

Then perform operations according to 7.3.2.2.

7.3.4 Spectrophotometric measurements

By setting the spectrophotometer to zero optical density with respect to water, is carried out spectrophotometric measurements (see note 4) painted the analyzed solution (7.3.2) and the corresponding solution of (7.3.3) at a wavelength of 543 nm in cuvettes with the thickness of the optical layer 2 see

Measure the optical density of the investigated solution and a solution comparison .

Note 4 — in order to carry out spectrophotometric measurements of all solutions, keeping them exactly 15 min after addition of acetate buffer solution (7.3.2), it is recommended to divide them into a series of six dimensions, i.e. for 12 flasks, as for large series of measurements, if you strictly do not follow the specified timeout, in solutions appears blurred, which leads to errors in the analysis results.

7.4 Construction of calibration curve

7.4.1 Preparation of calibration mixtures

A portion of iron (4.1) (1,00±0,01) g was placed in a six quartz glasses with a capacity of 100 cmeach and add the volumes of standard solution boron (4.11.2), as indicated in table 1 for steels with a mass fraction of boron up to 0,0005%, inclusive, and in table 2 for the steels with a mass fraction of boron more than 0.0005%.


Table 1 — Calibration solutions for steels with a mass fraction of boron from 0.0001% to 0.0005% of inclusive

Table 2 — Calibration solutions for steels with a mass fraction of boron from 0.0005% to 0,0120% inclusive

Next, carry out analysis as specified in 7.3.1, 7.3.2, 7.3.3.

7.4.2 Spectrophotometric measurements

By setting the spectrophotometer to zero optical density with respect to water, is carried out spectrophotometric measurements of the whole range of the calibration solutions with and without addition of a solution of sodium fluoride (4.10) at a wavelength of 543 nm in cuvettes with the thickness of the optical layer 2 see

7.4.3 Construction of calibration curve

Find the difference between the values of optical density of solutions with sodium fluoride and without it, and from the obtained subtracted value of the optical density of the zero solution.

Build a calibration graph of optical density resulting from the mass of boron in micrograms. The graph should be a straight line passing through the origin.

8 Processing of results

8.1 Calculation of optical density

Find the difference between the values of optical density for each analyzed solution and subtract the value of optical density obtained for a solution of a blank experiment under the same conditions. The optical density was determined by boron content is calculated by the formula

, (1)

where optical density is defined boron content;

 — the optical density of the analyzed solution;

 — optical density of the solution compare to the analyzed solution;

 — the optical density of the blank solution experience;

 — optical density of the solution compare to the blank solution experience.

8.2 Determination of boron content

With the help of calibration curve (7.4.3), the value of optical density find the mass of boron in micrograms in the sample solution.

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

, (2)

where is the mass of boron in the sample solution, µg;

is the mass of analytical portion (7.1), g;

 — mass fraction of boron in pure iron (4.1), % (it can be ignored when it does not affect the accuracy of the result).

8.3 Precision

The verification of this method was carried out in 14 laboratories in 6 countries to 5 levels of boron content in the lower region of the defined range in non-alloy steels and in 21 laboratories from 8 countries for 8 levels of boron content in the upper region of the designated range in other types of steels. Each laboratory conducted three (notes 5 and 6) definitions of each level of boron content.

Note 5 — Two of the three definitions was carried out under conditions of repeatability (convergence) in accordance with ISO 5725−1, i.e. one operator on the same instrument under the same experimental conditions with the same calibration graph in the shortest period of time.

Note 6 — Third determination was conducted at a different time (or another day) the same operator as in note 5, on the same device, but with a new calibration schedule.


Standard samples used for the study are given in tables B. 1 and B. 2 (Appendix B).

Statistical processing of the obtained results was carried out in accordance with ISO 5725−1, ISO 5725−3 according to the data obtained for 4 levels of boron content in the lower region of the defined range in non-alloy steels and 6 levels of boron content in the upper region of the designated range in other types of steel, respectively, within the specified area the content of boron.

The obtained data have established a logarithmic correlation between the boron content, the limits of repeatability (convergence) and reproducibility limits and the results of the study (see note 7), as shown in tables 3 and 4. The graphical presentation of precisionist is given in Annex C.

Note 7 — results obtained on the first day, I counted to a limit of repeatability (convergence) and reproducibility limit using the method according to ISO 5725−2. According to the results obtained in the first and second day, were calculated the limit intralaboratory reproducibility , using the method ISO 5725−3.


Table 3 — precision Data obtained for the contents of boron with a mass fraction of from 0.0001% to 0.0005% of inclusive

In percent (mass.)

Table 4 — precision Data obtained for the contents of boron with a mass fraction of from 0.0005% to 0,0120% inclusive

In percent (mass.)

The same method was used for processing the results obtained at 14 laboratories in 7 countries belonging to the eciss information/TC 20, for samples with 8 levels of boron content. The results of these tests to assess the precision is given in table D. 1 (Appendix D).

9 test report

The test report shall contain:

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

b) method used with reference to this standard;

c) test results;

d) especially marked when performing tests;

e) any operations not specified in this standard, or any additional operations that may affect the test results.

Annex a (informative). A schematic representation of a block of aluminum alloy

Appendix A
(reference)

_______________
The hole diameter must match the diameter of used chemical glass.

If necessary, the depth of the hole may match the level of solution in the glass.

Figure A. 1 — Schematic image of a block of aluminum alloy

_______________
The hole diameter must match the diameter of used chemical glass.

If necessary, the depth of the hole may match the level of solution in the glass.

Figure A. 2 — Schematic representation of the block of aluminum alloy

Annex b (informative). Additional information on international cooperative tests

The App
(reference)

In table 3 of this standard lists the results of international analytical testing performed in 1993 on 5 samples of non-alloy steels with participation of 14 laboratories in 6 countries.

The test results were published in document ISO/TC 17/SC 1 N 1031, March 1994

Graphical representation of precision data Annex C (figure C. 1).

The analyzed samples are presented in table B. 1.


Table B. 1 — Results of interlaboratory tests

In percent (mass.)

In table 4 of this standard given the results of international analytical testing performed in 1986 on the 8 samples with the participation of 21 laboratories in 8 countries.

The test results were published in document ISO/TC 17/SC 1 N 755, January 1989 (revision).

Graphical representation of the data precision of the results is given in Appendix C (figure C. 2).

The analyzed samples are presented in table B. 2.


Table B. 2 — Results of interlaboratory tests

In percent (mass.)

Application (reference). Graphical representation of precision data

Application
(reference)

;

;

,

where is the mean value of mass fraction of boron obtained in one day, % of mass;

the average value of the mass fraction of boron, obtained in different days, % wt.

Figure C. 1 Is a Logarithmic dependence between the mass fraction of boron , the limit of repeatability (convergence) and reproducibility limits and

;

;

,

where is the mean value of mass fraction of boron obtained in one day, % of mass;

the average value of the mass fraction of boron, obtained in different days, % wt.

Figure C. 2 — Logarithmic relationship between the mass fraction of boron , the limit of repeatability (convergence) and reproducibility limits and

Annex D (informative). Additional tests on precision made European countries

Appendix D
(reference)

The results of tests on precision made by European countries are shown in table D. 1.

The obtained data have established a logarithmic correlation between the boron content and the limits of repeatability (convergence) and reproducibility limits and the results of the study as shown in table D. 2.


Table D. 1

In percent (mass.)

Table D. 2

In percent (mass.)

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