GOST 26473.1-85
GOST 26473.1−85 Alloys and alloys based on vanadium. Method for the determination of boron (Change No. 1)
GOST 26473.1−85
Group B59
STATE STANDARD OF THE USSR
ALLOYS AND MASTER ALLOYS BASED ON VANADIUM
Method for the determination of boron
Vanadium base alloys and alloying elements. Method for determination of boron
AXTU 1709
Valid from 01.07.86
to 01.07.91*
_______________________________
* Expiration removed
by the decree of Gosstandart of the USSR from
(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 751
The Change N 1, approved and put into effect by the Decree of the USSR State Committee on management of quality and standards from
Change No. 1 made by the manufacturer of the database in the text IUS N 2, 1990
This standard sets the photometric method for the determination of boron (from 0.2 to 5%) in alloys and master alloys based on vanadium, the contents of related components which are shown in table.1.
Table 1
| The accompanying component |
Mass fraction, %, not more |
| Aluminium |
40 |
| Iron |
1,5 |
| Silicon |
1 |
| Manganese |
3,5 |
The method is based on the Stripping of boron in the form of boric acid pyrohydrolysis, the formation of the blue complex compounds of boron with dentriticum in an environment of concentrated sulfuric acid with subsequent fotometricheskie the color of the solution.
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 26473.0−85.
2. APPARATUS, REAGENTS AND SOLUTIONS
Photoelectrocolorimeter FEK-56 or similar device.
Analytical scale.
Libra technical.
Tile electric.
Bath water.
Electric resistance tubular type SUOL-0,25−1/12-M1, providing a heating temperature of 1300 °C.
The quartz tube with a length of 450−500 mm, an inner diameter of 20−25 mm.
Type autotransformer RNO-250−5.
Millivoltmeter-type M-64.
Thermocouple platinum-rhodium type TPP-11.
Pumps porcelain N 2, pre-calcined at 1000−1100 °C for 10−15 min, should be stored in a desiccator.
The hook is made of quartz glass tubes with a diameter of (5±1) mm and a length of (500±10) mm.
Desiccator with calcium chloride.
Calcium chloride calcined at 250−300 °C according to GOST 4460−77.
Flat-bottomed round flask with a capacity of 1 DM(steam generator).
Quartz conical flask with a capacity of 200 cm(receiver).
Flask cleaning (Tishchenko).
Nitrogen according to GOST 9293−74.
Installation for pyrohydrolysis (see drawing) consists of a tubular resistance furnaces. In the oven is inserted into a quartz tube with a drawn right angle outlet pipe length (250±20) mm and a diameter of 10−12 mm. To the upper part of the outlet tube is soldered coupler for refrigerator with a length of (450±10) mm and a diameter of 20−25 mm. End of the outlet tube is provided with barbitalom with holes 1−1. 5 mm. the Receiver is a quartz conical flask with a capacity of 200 cm. The steam used in the process of pyrohydrolysis, is formed in the steam generator, connected to the quartz tube by a transition at the socket (or through a rubber tube) and fed into the furnace with nitrogen (air), previously passed through the purifying bottles. The heating of the steam generator is performed on a hot plate.
1 — a gas cylinder; 2 — bottles for washing gases (i.e., with concentrated sulfuric acid; b — distilled water); 3 — hot plate; 4 — steam generator; 5 — tubular electric resistance furnace; 6 — boat-porcelain; 7 — platinum-platinum / rhodium thermocouple; 8 — quartz tube; 9 — refrigerator; 10 — breather pipe; 11 — flask-receiver; 12 — millivoltmeter; 13 — voltage transformer to control the temperature of the furnace
Quartz test tube with a capacity of 20−25 cmwith a massive stopper and the tapered cone type, PKM-25 CS 10/19.
Stopwatch.
The sieve with hole size to 0.074 µm to verify the training received in the laboratory sample.
Volumetric flasks with a capacity of 50, 200, 250 cmand 1 DM
.
Pipettes with a capacity of 2 and 5 cmwith divisions.
Pipettes with a capacity of 10, 15 and 20 cmwith no divisions.
Microburette with a capacity of 10 cmwith a scale division of 0.02 cm
.
Measuring beakers with a capacity of 25 and 100 cm.
Sulfuric acid GOST 4204−77, and the solution concentration of 2 mol/DM.
Diatreme (1,1-dianthraquinone), solution concentration of 5 g/lin concentrated sulfuric acid: 1 g of centrimide placed into a dry volumetric flask with a capacity of 200 cm
with a glass stopper, pour to the mark with concentrated sulfuric acid, the flask stoppered, was stirred until complete dissolution of the sample reagent.
Boric acid according to GOST 9656−75.
Standard solution boron (spare) containing 0.1 mg/cm(100 g/cm
) of boron: 0,5715 g of boric acid dissolved in sulfuric acid concentration of 2 mol/DM
. The solution was transferred to volumetric flask with a capacity of 1 DM
, adjusted to the mark with the same solution of sulfuric acid.
The boron solution (working) containing 0.01 mg/cm(10 µ g/cm
) of boron, is prepared by dilution of the standard backup solution 10 times with a solution of sulfuric acid concentration of 2 mol/DM
on the day of use.
(Changed edition, Rev. N 1).
3. PREPARATION FOR ASSAY
Prepare the installation for pyrohydrolysis, visually inspecting the condition of furnace, electric, insulation of the live wires for grounding. Include a hot plate for heating water in the steam generator to boil, turn on the furnace, regulate the flow of nitrogen (air), setting the rate of 1−2 bubbles per second. A bubbler immersed in a receiver containing 100 cmof water. Oven heated to 400 °C.
4. ANALYSIS
4.1. A portion of the sample weighing 0.1 g donkersteeg in the form of powder (particle size less than 74 µm) was transferred in a thin layer in a porcelain boat which is placed in a quartz tube installation pyrohydrolysis in the center of the oven, and immediately connect the steam generator to the device for pyrohydrolysis. The furnace temperature was raised to 1300 °C and hold pyrohydrolysis for 30−40 minutes, then oven off and disconnect the steam generator tube from the device.
Bubbler splash of water. Received in the receiver solution transferred to a volumetric flask with a capacity of 250 cm, was adjusted to the mark with water.
For boron determination aliquot part of the solution from 2 to 20 cm(depending on the mass fraction of boron) containing 15−100 micrograms of boron, taken in a volumetric flask with a capacity of 50 cm
, add water up to 20 cm
, poured carefully dropwise 20 cm
of concentrated sulfuric acid, cooled to room temperature, adjusted to the mark with water. From the resulting solution are taken 2 cm
in dry quartz cylinder, pour 13 cm
of concentrated sulfuric acid and 5 cm
of a solution of centrimide. The contents of the cylinder to stand for 1 h in a boiling water bath. The cylinder with the solution was then cooled to room temperature and measure the optical density of the solution on the photoelectrocolorimeter using a filter with maximum transmittance at a wavelength of ~630 nm and cuvette thickness of the light absorbing layer of 20 mm in relation to concentrated sulphuric acid.
Simultaneously with the analysis of a series of tests (before samples) through all stages of the analysis spend control experience (for pollution control installation and reagents). The value of the optical density of the solution in the reference experiment shall not exceed 0,03, otherwise should clean the installation and to change the reagents. The value of the optical density of the solution in the reference experiment is subtracted from the value of the optical density of the analyzed solution.
A lot of find boron in the calibration schedule for the computed value of the optical density
I.
4.2. Construction of calibration curve
In a volumetric flask with a capacity of 50 cmis injected from microburette 1,5; 3,0; 5,0; 8,0 and 10,0 cm
working standard solution of boron, which corresponds to 15, 30, 50, 80 and 100 micrograms of boron, add water up to 20 cm
, poured carefully dropwise 20 cm
of concentrated sulfuric acid and then act as described in section 4.1.
5. PROCESSING OF THE RESULTS
5.1. Mass fraction of boron () in percent is calculated by the formula
where is the mass of boron was found in the calibration schedule, mcg;
— capacity volumetric flasks, cm
;
— aliquotes volume of the solution taken for the determining, cm
;
— the weight of the portion of the sample,
5.2. The values of permissible differences are listed in table.2.
Table 2
| Mass fraction of boron, % |
Allowable difference, % |
2·10 |
1,5·10 |
| 1,0 |
0,2 |
| 3,0 |
0,3 |
| 5,0 |
0,4 |
(Changed edition, Rev. N 1).
