GOST 26473.12-85

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  ГОСТ 26473.12-85

GOST 26473.12−85 Alloys and alloys based on vanadium. Method of atomic-absorption analysis (with Change No. 1)

GOST 26473.12−85

Group B59

STATE STANDARD OF THE USSR

ALLOYS AND MASTER ALLOYS BASED ON VANADIUM

Method of atomic-absorption analysis

Vanadium base alloys and alloying elements. Method of atomic-absorption analysis

AXTU 1709

Valid from 01.07.86
to 01.07.91*
_______________________________
* Expiration removed
by the decree of Gosstandart of the USSR from 14.05.91 N 680
(IUS N 8, 1991). — Note the manufacturer’s database.

DEVELOPED by the Ministry of nonferrous metallurgy of the USSR

PERFORMERS

Yu. A. Karpov, E. G. Nembrini, V. G., Miscreants, V. V. Nedler, V. M. Mikhailov, L. G. Agapova, G. N. Andrianov, A. V. Antonov, V. D. Dozen, M. A. Desyatkova, T. I. Kirillova, L. I. Kirsanov, I. E. Korepin, V. A. Orlova, N. Rasnitsyn, N. Suvorova, N. L. Tomasev, M. W. Schmidt, L. N. Filimonov

INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

Member Of The Board Of A. P. Snurnikov

APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on standards of 25 March 1985 N 752

The Change N 1, approved and put into effect by the Decree of the USSR State Committee on management of quality and standards from 14.05.91 N 678 from 01.01.92

Change No. 1 made by the manufacturer of the database in the text IUS N 2, 1990


This standard applies to alloys and alloys based on vanadium and installs atomic absorption method for the determination of components and impurities, are given in table.1.

Table 1

The method is based on measuring atomic absorption of resonant lines of the determined elements with the introduction of the analyzed solution into air-acetylene flame or the flame of a mixture of acetylene with nitrous oxide.

(Changed edition, Rev. N 1).

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 26473.0−85.

2. APPARATUS, REAGENTS AND SOLUTIONS

Spectrophotometer of atomic absorption, permitting atomization in the flame.

Acetylene according to GOST 5457−75.

The nitrous oxide.

Lamps hollow cathode for aluminium, vanadium, silicon, iron, manganese, molybdenum, and titanium.

Burner with a slit length of 50 or 100 mm.

Analytical scale.

Libra technical.

Muffle furnace with thermostat providing temperatures up to 800 °C.

Tile electric.

Glasses glass with a capacity of 100 cm.

The quartz glasses with a capacity of 100 cm.

Volumetric flasks with a capacity of 100 cm, 1 DM.

Cup platinum.

Cup of silver.

Measuring beakers with a capacity of 25 and 100 cm.

Pipettes with a capacity of 5 cmwith divisions.

Pipettes with a capacity of 5 and 20 cm,with no divisions.

Funnels, glass, conical.

The filter paper ashless white ribbon.

Pipettes plastic.

Sulfuric acid GOST 4204−77, diluted 1:1.

Nitric acid according to GOST 11125−84 diluted 1:1.

Hydrofluoric acid according to GOST 10484−78.

Hydrochloric acid by the GOST 3118−77, diluted 1:1.

Potassium hydroxide according to GOST 24363−80.

Barium chloride according to GOST 4108−72, solution concentration 100 g/DM.

Iron metal has been restored.

Silicon dioxide according to GOST 9428−73.

Molybdenum metal with a basic substance content not less than 99.9%.

Aluminium metal according to GOST 11069−74*.
______________
* On the territory of the Russian Federation GOST 11069−2001. — Note the manufacturer’s database.

Manganese (IV) oxide according to GOST 4470−79.

Titanium sponge according to GOST 17746−79*.
______________
* On the territory of the Russian Federation GOST 17746−96. — Note the manufacturer’s database.

The vanadium metal content of the basic substance is not less than 99.9%.

Chrome metal according to GOST 5905−79*.
______________
* On the territory of the Russian Federation GOST 5905−2004. — Note the manufacturer’s database.

Copper metal with a mass fraction of basic substance is no less than 99.9%.

Silicon powder, calcined at 500 °C, with a mass fraction of basic substance is no less than 99.9%.

Sodium silicate, 9-water.

Sodium carbonate according to GOST 83−79.

Sodium hydroxide according to GOST 4328−77, solution with concentration of 0,1 mol/DM.

(Changed edition, Rev. N 1).

2.1. Preparation of standard solutions

Standard solution of iron (spare) containing 1 mg/cmiron: 1 g of iron metal is placed in a beaker with a capacity of 100 cm, 50 cm pour thenitric acid, and dissolve in low heat. The solution was cooled to room temperature and transferred to a volumetric flask with a capacity of 1 DM, adjusted to the mark with water.

A standard solution of silicon containing 1 mg/cmof silicon, prepared one way.

The first method: sample weight 2,1309 g of silicon dioxide is placed in a silver Cup, add 6−8 g of potassium hydroxide, poured 30 cmof water, stirred and heated until complete dissolution. The solution was transferred to volumetric flask with a capacity of 1 DM, adjusted to the mark with water.

The second way: a portion of ground 2,1309 g of silicon dioxide or 1,0000 g of the calcined powder of silicon alloys with 15 g of sodium carbonate in a platinum crucible, cooled and leached with a solution of sodium hydroxide and made up to a volume of 1 DMthe same solution.

Third method: preparation of a standard solution of silicon GOST 4212−76 of sodium silicate.

Accurate mass concentration of silicon is set by the gravimetric method. To do this, in the platinum Cup pipetted 20 cmstandard solution silicon, pour 2−3 cmof sulphuric acid diluted 1:1, the contents of the Cup was boiled down to 2−3 cmand cooled to room temperature and carefully, drop by drop, poured another 5−6 cmof concentrated sulfuric acid. Then the solution is heated to release dense fumes of sulphuric anhydride; cooled to room temperature, pour 2−3 cmof water, again evaporated until dense fumes of sulphuric anhydride, cooled to room temperature and poured 100 cmof water. Heat the solution to 70−80 °C, the precipitate was filtered off on filter «white ribbon» and washed several times with hot water before removing from the precipitate the sulfate ions (reaction the last drops of the filtrate with a solution of barium chloride). The filter with precipitate was placed in a platinum crucible, dried, incinerated and calcined in a muffle furnace at 700−800 °C for 1−1,5 h. the Crucible with residue was cooled to room temperature in desiccator, weigh. To the residue in the crucible add a polyethylene pipette 5 cmhydrofluoric acid, a few drops of concentrated sulfuric acid and heated until the termination of allocation of steams of sulfuric acid. The crucible with the precipitate is calcined again in a muffle furnace for 10−15 minutes, cool and weigh.

Mass concentration () of a standard solution of silicon, expressed in mg/cm, calculated by the formula

,

where is the mass of the sludge before treatment with hydrofluoric acid, mg;

 — the mass of sludge after treatment hydrofluoric acid, mg;

0,4674 — the ratio of silicon dioxide on silicon;

 — the volume of a standard solution are taken to determine cm.

A standard solution of manganese (spare) containing 1 mg/cmmanganese: 1,583 g of manganese dioxide were placed in a glass with a capacity of 100 cm, flow 20 cmof hydrochloric acid, heated to complete dissolution, the resulting solution was evaporated to dryness, the residue dissolved in water, transferred into a flask with a capacity of 1 DM, adjusted to the mark with water.

Accurate mass concentration of manganese set titrimetric method in accordance with the requirements of GOST 26473.5−85. To do this in a conical flask with a capacity of 250 cmpipetted 20 cmstandard solution of manganese, dilute with water to 100 cm, add 7 cmof a solution of orthophosphoric acid and further define manganese at sec. 3.

Mass concentration () of a standard solution of manganese, expressed in mg/cm, calculated by the formula:

,

where is the volume of solution of oxalic acid consumed for titration, cm;

0,001099 — mass concentration of solution of oxalic acid, expressed in g/cmof manganese;

 — the volume of a standard solution of manganese, was taken for the determination of manganese, see.

A standard solution of aluminum containing 10 mg/cmof aluminium: 1 g of aluminum metal is placed in a beaker with a capacity of 100 cm, poured portions 20 cmof hydrochloric acid and heated until complete dissolution, the solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

A standard solution of vanadium containing 10 mg/cmvanadium: 1 g of metallic vanadium were placed in a glass with a capacity of 100 cm, flow 10 cmof sulphuric acid and in portions of 5−10 cmof nitric acid, is dissolved when heated, is evaporated to release vapors of sulphuric anhydride, cooled to room temperature, add to the walls of the flask 20 cmof water, gently mixed, transferred into a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

A standard solution of titanium, containing 10 mg/cmtitanium: 1 g of titanium sponge is placed in a beaker with a capacity of 100 cm, flow 15 cmsulphuric acid and a few drops of hydrofluoric acid, dissolved by heating, the solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water.

A standard solution of molybdenum containing 10 mg/cmof molybdenum, 1 g of metallic molybdenum were placed in a glass with a capacity of 100 cm, flow 20 cmof sulfuric acid and 10 cmof nitric acid, heated to complete dissolution. The solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water.

Standard solution of chromium (spare) containing 10 mg/cmchromium: 1 g of chromium metal is placed in a beaker with a capacity of 100 cmand dissolved by heating in 20 cmof sulphuric acid diluted 1:1. Upon dissolution of poured 10 cmof nitric acid, diluted 1:1, heating was continued to release sulfuric acid vapors, cooled, poured 50 cmof water, heated to dissolve the salts, re-cooled, transferred to a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

A solution of chromium (work) containing 1 mg/cmchromium, prepared by dilution of the standard backup solution with water in 10 times.

A standard copper solution containing 1 mg/cmcopper: 1 g of copper metal is placed in a beaker with a capacity of 100 cm, pour 5 cmof nitric acid, dissolve by heating, dilute to 50 cmof water, boil to remove oxides of nitrogen. The solution was cooled to room temperature and transferred to a volumetric flask with a capacity of 1 DM, adjusted to the mark with water.

(Changed edition, Rev. N 1).

3. PREPARATION FOR ASSAY

3.1. Preparation of solutions comparison

3.1.1. Working solutions for the determination of silicon, iron, manganese and copper is prepared by appropriate dilution of standard solutions and for chromium standard working solution. In six volumetric flasks with a capacity of 100 cmis administered at 0,25; (manganese — 0,2); 0,5; 1,0; 2,0; 3,0; 5,0 cmstandard solutions of silicon, iron, manganese, copper, chromium, adjusted to the mark with water, getting the solutions containing 0,0025 (manganese 0,002), 0,005; 0,01; 0,02; 0,03; 0,05 mg/cmof these elements in solution, which corresponds to the following weight fractions of elements in the sample: a 0.05 (manganese 0,04), 0,1, 0,2, 0,4, 0,6 and 1.0% of silicon, iron, manganese, copper and chromium.

To determine (if necessary) of manganese at a content of up to 2.5% additionally prepare working solution comparison: in a volumetric flask with a capacity of 100 cmis administered at 5.0 cmstandard solutions of silicon in iron, the standard working solution of chromium and 12.5 cmstandard solution of manganese, adjusted to the mark with water, getting the solutions containing 0.05 mg/cmof silicon, iron, chromium, and 0.125 mg/cmof manganese, which corresponds to 1% of silicon, iron, chromium, and 2.5% manganous pH

.

3.1.2. For the determination of vanadium, molybdenum, aluminum, titanium, chromium and iron in the alloys of the vanadium-molybdenum-aluminium-iron-chromium, vanadium-molybdenum-aluminium-titanium, vanadium-aluminum-titanium, vanadium-aluminum cook successively a series of four solutions comparison.

Series 1, solutions N 1−2. In two volumetric flasks with a capacity of 100 cmhas consistently injected the standard solutions 15.5 and 17.5 cmof vanadium; 15.0 17.5 cmmolybdenum; 2.5 and 5.0 cmchromium; 25 and 50 cmof iron; 14 and 7 cmof aluminium, adjusted to the mark with water. Get solutions containing 1.55 and 1.75 mg/cmvanadium, 1.50 and 1.75 mg/cmof molybdenum, 0.25 and 0.5 mg/cmof chromium and iron of 1.4 and 0.7 mg/cmof aluminium.

Series 1, No. 3−4 solutions (working solutions). Each of the resulting solutions of N 1−2 was diluted in 20 times. For this, 5 cmof solution is transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water, get fluids containing 0,0775 and 0,0875 mg/cmvanadium, and 0,075 0,0875 mg/cmof molybdenum, 0.0125 and 0.025 mg/cmof chromium and iron, and 0,070 0,035 mg/cmof aluminium, which corresponds to the following weight fractions of elements in the sample: 31 and 35% vanadium, 30 and 35% molybdenum, 5 and 10% of chromium and iron, 28% and 14% of aluminium.

Series 2, the solutions of N 1−2. In two volumetric flasks with a capacity of 100 cmhas consistently injected the standard solutions of 15 and 17 cmof vanadium and 2.5, 17.5 and 20 cmof molybdenum, 5.0 and 10.5 cmaluminium, 12.5 and 3.5 cmtitanium, adjusted to the mark with water. Get solutions containing 1.5 and 1.7 mg/cmof vanadium, and 0.25, 1.75 and 2.0 mg/cmof molybdenum, and 0.5 to 1.05 mg/cmof aluminium, 1.25 and 0.35 mg/cmof titanium.

Series 2, solution No. 3−4 (working solutions). Each of the resulting solutions of N 1−2 was diluted in 20 times. For this, 5 cmof solution is transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water, getting the solutions containing 0,075 and about 0.085 mg/cmvanadium, 0,0125, 0,0875 and 0.10 mg/cmof molybdenum, 0.025 and 0,0525 mg/cmaluminum of 0.0625 and 0,0175 mg/cmtitanium, which corresponds to the following weight fractions of elements in the sample: 30 and 34% of vanadium, 5.35 and 40% molybdenum, 10% and 21% of aluminium, 25 and 7% titanium.

Series 3, the solutions of N 1−3. Three volumetric flasks with a capacity of 100 cmhas consistently injected the standard solutions: 22,5, 25 and 30 cmof vanadium; 25, 21 and 13.5 cmof aluminium; of 1.0, 2.5 and 5.0 cmof titanium was adjusted to the mark with water. Get solutions containing of 2.25, 2.5 and 3.0 mg/cmvanadium of 2.5, 2.1 and 1.35 mg/cmof aluminium, of 0.1, 0.25 and 0.5 mg/cmof titanium.

Series 3, 4−6 N solutions (working solutions). Each of the resulting solutions of N 1−3 was diluted in 20 times. For this, 5 cmof solution is transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water, get fluids containing 0,1125, 0.125 and 0.15 mg/cmvanadium, 0,125, 0,105 and 0,0675 mg/cmof aluminium, of 0.005, 0.0125 and 0.025 mg/cmof titanium, which corresponds to the following weight fractions of elements in the sample: 45, 50 and 60% vanadium, 50, 42 and 27% aluminum, 2.5 and 10% titanium.

Series 4, the solutions of N 1−2. In two volumetric flasks with a capacity of 100 cmhas consistently injected the standard solutions of 35 and 40 cmsize: 15 and 10 cmof aluminium, adjusted to the mark with water. Get solutions containing 3.5 and 4.0 mg/cmvanadium, 1.5 to 1.0 mg/cmof aluminium.

Series 4, No. 3−4 solutions (working solutions). Each of the resulting solutions of N 1−2 was diluted in 20 times. For this, 5 cmof solution is transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water, get fluids containing 0,175 and 0.20 mg/cmvanadium, and 0.05 to 0.075 mg/cmof aluminium, which corresponds to the following weight fractions of the elements

in the sample: 70% and 80% vanadium, 30% and 20% aluminum.

3.1.1, 3.1.2. (Changed edition, Rev. N 1).

3.2. Sample preparation

A portion of the sample weighing 0.5 g was placed in a quartz glass with a capacity of 100 cm, flow 10 cmof sulphuric acid diluted 1:1, and 10 cmof nitric acid, diluted 1:1, heated to complete dissolution of the sample. The solution was transferred to volumetric flask with a capacity of 100 cm, cooled, adjusted to the mark with water. The resulting solution was used for the determination of silicon, iron, chromium, copper, and manganese.

For the determination of the alloy components (with the contents more 1%): aluminum, vanadium, iron, molybdenum, titanium and chromium, the resulting solution is diluted with water to 20 times (aliquot part — 5 cm,transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water.

3.3. Analysis

The device is prepared to work according to the instructions on the product. Conditions for atomic absorption measurement are given in table.2. For carrying out atomic absorption determination after switching the network pick a position lamp complete cathode (depending on the analyzed element), to the current, specified in the passport on the lamp, the reading of the microammeter was maximum. After the lamp to warm up for 15−20 min. light the appropriate flame when spraying it working solution compare with the maximum concentration of the element choose the position of the burner and the rate of spray, ensuring maximum atomic absorption analytical line of the element.

Table 2

In optimum conditions of measurement is sprayed into the burner flame is consistently the solution of the sample and working solutions comparison, choosing them so as to give one greater and the other less analytical signal (the testimony of a digital display device) than the solution of the sample (the method of limiting solutions), repeating the measurement procedure three times and calculate the arithmetic mean value of the analytical signal.

In the determination of silicon, iron, manganese simultaneously through the analysis of spend control experience (experience on contamination of reagents). The average (of three) value of the analytical signal in the reference experiment is subtracted from the values of the analytical signal of the sample solution.

3.2, 3.3. (Changed edition, Rev. N 1).

4. PROCESSING OF THE RESULTS

4.1. Mass fraction of aluminum, vanadium, iron, silicon, manganese, molybdenum and titanium () in percent is calculated by the formula

,

where  — mass fraction of the element in the working solution compare with the smaller (relative to analyte) content of the element, %;

 — mass fraction of the element in the working solution compare with a large (relative to analyte) content of the element, %;

the value of optical density of the working solution compare with the smaller (relative to analyte) content of the designated element;

the value of optical density of the working solution compare with a large (relative to analyte) content of the designated element;

the value of optical density of the analyzed solution.

4.2. The values of permissible differences given in table.3.

Table 3

(Changed edition, Rev. N 1).