GOST 19863.5-91

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  ГОСТ 19863.5-91

GOST 19863.5−91 Alloy of titanium. Methods of iron determination

GOST 19863.5−91

Group B59

STATE STANDARD СОЮ3А SSR

ALLOYS OF TITANIUM

Methods of iron determination

Titanium alloys.
Methods for the determination of iron

AXTU 1709

Date of introduction 1992−07−01

INFORMATION DATA

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

DEVELOPERS

V. G. Davydov, doctor of engineering. Sciences; V. A. Moshkin, PhD. tech. Sciences; G. I. Friedman, PhD. tech. Sciences; L. A. Tenyakova; M. N. Gorlova, PhD. chem. Sciences; L. V. Antonenko, O. L. Sikorska, PhD. chem. Sciences

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from 05.05.91 N 625

3. REPLACE GOST 19863.5−80

4. The frequency of inspection — 5 years

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard specifies the photometric (with a mass fraction of from 0.01 to 2.0%) and atomic absorption (at a mass fraction of from 0.01 to 5.0%) methods for determination of iron.

1. GENERAL REQUIREMENTS

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

1.1.1. For the results analysis be the arithmetic mean of results of two parallel measurements.

2. PHOTOMETRIC METHOD FOR DETERMINATION OF IRON

2.1. The essence of the method

The method is based on dissolving the sample in sulfuric acid, the recovery of ferric iron to ferrous with hydroxylamine hydrochloride, the formation of the orange complex of bivalent iron with 1,10-phenanthroline at pH 5 and measuring the optical density of the solution at a wavelength of 510 nm.

2.2. Apparatus, reagents and solutions

Spectrophotometer or photoelectrocolorimeter.

Sulfuric acid according to GOST 4204 density 1.84 g/cmand a solution of 1:3.

Hydrochloric acid according to GOST 3118 density of 1.19 g/cmand a solution of 1:1.

Hydroxylamine hydrochloride according to GOST 5456, solution 100 g/DM.

1,10-fenantrolin.

Sodium acetate according to GOST 199.

Tartaric acid according to GOST 5817.

The mixture of reagents in the conical flask with a capacity of 1 DMwas placed 1.25 g of 1.10-phenanthroline, pour 500 cmof water and heated until dissolved. To the solution was added 40 g of tartaric acid, 500 g sodium acetate, add water to 1 DMand stirred. The solution is ready for use within 3 weeks.

Reactive iron (restored).

Standard iron solution

Solution a: 0.1 g of iron is placed in a beaker with a capacity of 250 cm, 80 cm pour thehydrochloric acid solution, cover with a watch glass and dissolved under heating. The solution was cooled to room temperature, rinse watch glass with water glass, which had a dissolution, transferred to a volumetric flask with a capacity of 1000 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of iron.

Solution B: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, poured 5cmof hydrochloric acid, made up to the mark with water and mix. The solution is prepared before use.

1 cmof solution B contains 0,00001 g

iron.

2.3. Preparation for assay

Before analysis the chips samples atminciai.

2.4. Analysis

2.4.1. A portion of sample weighing 0.2 g was placed in a conical flask with a capacity of 100 cm, 30 cm, pour thesolution of sulphuric acid, cover the flask with a watch glass or funnel and heated to dissolve the sample, maintaining the initial volume with water.

The solution is poured dropwise a solution of hydroxylamine hydrochloride to the disappearance of a purple color in excess of five drops, boil 1−2 min, cool to room temperature, transfer the solution into a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

2.4.2. Aliquot part of the solution in accordance with the table.1 is transferred to a volumetric flask with a capacity of 100 cm, pour water up to 60 cm, 5 cmsolution hydroxylamine hydrochloride, 20 cmof a mixture of reagents, after 10 minutes, add water to mark and mix.

Table 1

2.4.3. Optical density of the solution measured after 30 min at a wavelength of 510 nm in a cuvette with a layer thickness fotometricheskogo 30 mm.

Solution comparison is the solution of the reference experiment, which is prepared according to claim.2.4.1 and 2.4.2 all used in the analysis reagents.

In the analysis of alloys containing chromium, Nickel and vanadium, the solution of the comparison serves as a compensating solution: aliquot part of the sample solution according to table.1 is transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

In this case, the optical density of the solution in the reference experiment is measured relative to the water and subtracted from the optical density of the solutions of the sample.

Mass fraction of iron calculated according to the calibration schedule.

2.4.4. Construction of calibration curve

Ten of the eleven volumetric flasks with a capacity of 100 cmmeasured 0,5; 1,0; 1,5; 2,0; 2,5; 3,0; 3,5; 4,0; 4,5; 5,0 cmstandard solution B, which corresponds to 0,000005; 0,00001; 0,000015; 0,00002; 0,000025; 0,00003; 0,000035; 0,000035,* 0,00004; 0,000045; 0,00005 grams of iron in all flasks pour 5 cmof the solution in the reference experiment and then continue on PP.2.4.2 and 2.4.3. Solution comparison is the solution not containing iron.
________________
* Consistent with the original. — Note the manufacturer’s database.

According to the obtained values of optical density of the solutions and their corresponding masses of iron to build the calibration graph.

2.5. Processing of the results

2.5.1. Mass fraction of iron () in percent is calculated by the formula

, (1)

where is the mass of iron in the sample solution found by the calibration schedule g;

 — weight of sample in aliquote part of the solution,

2.5.2. Discrepancies in the results must not exceed the values given in table.2.

Table 2

3. ATOMIC ABSORPTION METHOD FOR DETERMINATION OF IRON

3.1. The essence of the method

The method is based on dissolving the sample in hydrochloric and bridgestation acids and measuring the nuclear absorption of iron at a wavelength of 248.3 nm in a flame acetylene-air.

3.2. Apparatus, reagents and solutions

Spectrophotometer of atomic absorption with a radiation source for iron.

Acetylene according to GOST 5457.

Hydrochloric acid according to GOST 3118 density of 1.19 g/cm, mortar is 2:1 and 1:1.

Nitric acid according to GOST 4461 density of 1,35−1,40 g/cm.

Hydrofluoric acid according to GOST 10484.

Boric acid according to GOST 9656.

Acid bridgestation: 280 cmhydrofluoric acid at a temperature of (10±2) °C add portions 130 g of boric acid and stirred. The solution is prepared and stored in a plastic container.

Titanium sponge according to GOST 17746* stamps TG-100.
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* On the territory of the Russian Federation GOST 17746−96. — Note the manufacturer’s database.

Solutions titanium

Solution A, 20 g/DM: 4 g of titanium was placed in a conical flask with a capacity of 250 cm, 160 cm add asolution of hydrochloric acid 2:1, 8 cmbridgestation acid and dissolved with moderate heating. After dissolution of the sample add 2 cmof nitric acid and boil the solution for 1 min. the Solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 200 cm, made up to the mark with water and mix.

Solution B, 10 g/l, 1 g of titanium was placed in a conical flask with a capacity of 250 cm, add 80 cmof a hydrochloric acid solution of 2:1, 4 cmbridgestation acid and dissolved with moderate heating.

After dissolution, the sample is added twenty drops of nitric acid and boil the solution for 1 min. the Solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

Carbonyl iron according to GOST 13610.

Standard iron solution

Solution a: 1 g of pure carbonyl iron is dissolved in 50 cmof a hydrochloric acid solution 1:1, add a few drops of nitric acid, boil the solution for 1−2 min. the Solution was cooled to room temperature, transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.001 g of iron.

Solution B: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

1 cmof solution B contains 0,

0001 grams of iron.

3.3. Preparation for analysis according to claim 2.3.

3.4. Analysis

3.4.1. A portion of the sample weight in accordance with table.3 is placed in a conical flask with a capacity of 100 cm, add 20 cmof a hydrochloric acid solution of 2:1, 1 cmbridgestation acid and dissolved with moderate heating.

Table 3

After dissolution of the sample add 5−10 drops of nitric acid and boil the solution for 1 min. the Solution was cooled to room temperature, transferred to a volumetric flask with a capacity according to table.3, a solution of hydrochloric acid 1:1 (see table.3), made up to the mark with water and mix.

3.4.2. When the mass fraction of iron in excess of 1.0 to 5.0% selected aliquot part of the solution is 20 cm, placed in a volumetric flask with a capacity of 100 cm, add 2 cmof hydrochloric acid of 1:1, made up to the mark with water and mix.

3.4.3. The solution in the reference experiment is prepared according to claim.3.4.1 and 3.4.2.

3.4.4. Construction of calibration curve

3.4.4.1. When the mass fraction of iron from 0.01 to 0.1%

In six volumetric flasks with a capacity of 100 cmpoured in 25 cmof a solution of titanium And, in five of them measure 0,5; 1,5; 3,0; 4,5; 6,0 cmstandard iron solution B, which corresponds to 0,00005; 0,00015; 0,0003; is 0 00 045; 0.0006 g of iron.

3.4.4.2. When the mass fraction of iron in excess of 0.1 to 1.0%

In six volumetric flasks with a capacity of 100 cmpour 10 cmof a solution of titanium Used, five of them measure 1,0; 2,5; 5,0; 7,5; 10,0 cmstandard iron solution B, which corresponds to 0,0001; 0,00025; 0,0005; 0,00075; 0.001 g of iron.

3.4.4.3. When the mass fraction of iron in excess of 1.0 to 5.0%

In six volumetric flasks with a capacity of 100 cmpour 2 cmof a solution of titanium Used, five of them measure 2,0; 4,0; 6,0; 8,0; 10,0 cmstandard iron solution B, which corresponds to 0,0002; 0,0004; about 0.0006; 0.0008 inch; 0.001 g of iron.

3.4.4.4. The solutions in the flasks prepared according to claim.3.4.4.1, 3.4.4.2, 3.4.4.3, add 2 cmof hydrochloric acid 1:1, made up to the mark with water and mix.

3.4.5. The sample solution, solution control experience and solutions to build the calibration curve is sprayed in the flame acetylene-air (oxidative) and measure the atomic absorption of iron at a wavelength of 248.3 nm.

According to the obtained values of atomic absorption and corresponding mass concentrations of iron to build a calibration curve in the coordinates «Value of atomic absorption — Mass concentration of iron, g/cm».

Mass concentration of iron in the sample solution and in the solution of control and experience determined by the calibration schedule.

3.5. Processing of the results

3.5.1. Mass fraction of iron () in percent is calculated by the formula

, (2)

where  — mass concentration of iron in the sample solution found by the calibration schedule, g/cm;

 — mass concentration of iron in solution in the reference experiment, was found in the calibration schedule, g/cm;

 — the volume of the sample solution, cm;

 — the weight of the portion in the sample solution or in a suitable aliquote part of the sample solution, g

.

3.5.2. Discrepancies in the results must not exceed the values given in table.4.

Table 4