GOST 3240.4-76

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  ГОСТ 3240.4-76

GOST 3240.4−76 magnesium Alloys. Methods of determining India (with Change No. 1)

GOST 3240.4−76

Group B59

INTERSTATE STANDARD

MAGNESIUM ALLOYS

Methods definition India

Magnesium alloys.
Methods for determination of indium

ISS 77.120.20
AXTU 1709

Date of introduction 1978−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of aviation industry of the USSR

2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 28.12.76 N 2889

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Limitation of actions taken by Protocol No. 2−92 of the Interstate Council for standardization, Metrology and certification (ICS 2−93)

6. EDITION with Change No. 1, approved in June 1987 (IUS 11−87)


This standard sets the polarographic method for the determination of indium (in mass fraction of indium from 0.05 to 2%).

The method is based on restoring India on dripping mercuric electrode at a potential of recovery from minus 0.4 to minus 0.6 V.

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis according to GOST 3240.0.

2. EQUIPMENT, REAGENTS, SOLUTIONS

Electronic polarograph type of OP or other type, providing the sensitivity.

Hydrochloric acid according to GOST 3118, diluted 1:1.

Standard solution India; prepared as follows: 1 g of indium GOST 10297 brand Ин2 dissolved in 30 cmof hydrochloric acid. The solution was transferred to volumetric flask with a capacity of 1 DM, adjusted to the mark with water and mix.

1 cmof the solution contains 0.001 g of India.

Primary magnesium ingots according to GOST 804 in the form of chips.

Inert gas (nitrogen, argon or helium).

(Changed edition, Rev. N 1).

3. ANALYSIS

3.1. A portion of magnesium alloy take, depending on content of indium in the amounts indicated in the table.1.

Table 1

Then the sample is dissolved in 30 cmof hydrochloric acid, cooled and transferred to volumetric flask with a capacity of 100 cm, adjusted to the mark with hydrochloric acid, stirred and removed a diffusion wave India at the potentials of recovery from minus 0.4 to minus 0.6 V. Before removing the diffusion wave solution is aerated with a current of inert gas for 5 min.

Mass fraction of India find additives or calibration schedule.

3.2. Construction of calibration curve

The weight of magnesium take, depending on the mass fraction of indium in the amount indicated in the table.1, five glasses with a capacity of 100 cm, is dissolved in 30 cm. hydrochloric acid are added sequentially in each Cup of 0; 0,5; 1,0; 5,0; 10,0 and 20 cmstandard solution India, which corresponds to 0; 0,0005; 0,0010; 0,0050; and 0,0100 0,0200 g of indium, and the solution was transferred to volumetric flasks with a capacity of 100 cm, made up to the mark with hydrochloric acid, stirred and removed a diffusion wave India at a potential of minus 0.4 to minus 0.6 V. Before removing the diffusion wave solution is aerated with a current of inert gas for 5 min.

Sec. 3. (Changed edition, Rev. N 1).

4. PROCESSING OF THE RESULTS

4.1. Mass fraction of indium (in) in percent is calculated by the formula

,

where the wave height of the investigated solution;

 — wave heights of the investigated solution with the addition of a standard solution India, mm;

 — mass of India, corresponding to the standard additive, g;

 — the weight of the portion of alloy,

(Changed edition, Rev. N 1).

4.2. Mass fraction of India for the calibration graph () in percent is calculated by the formula

,

where the wave height of test solution, mm;

 — the total volume of solution, cm;

 — the ratio of the height of the standard solution in mm concentration, mg/DM;

 — the weight of the portion of alloy,

4.3. Allowable absolute differences of the results of the parallel definitions should not exceed the values given in table.2.

Table 2

(Changed edition, Rev. N 1).

5. CONTROL OF MEASUREMENT ACCURACY

To control the accuracy of measuring the mass fraction of indium from 0.05 to 2% using the state standard samples of magnesium alloys, industry-standard samples and standard samples of the enterprise of magnesium alloys, issued in accordance with GOST 8.315. Accuracy control measurement is carried out in accordance with GOST 25086.

Allowed to control the accuracy of measuring the mass fraction of indium by the method of additions.

(Added, Rev. N 1).