GOST 26473.5-85
GOST 26473.5−85 Alloys and alloys based on vanadium. Method for the determination of manganese (Change No. 1)
GOST 26473.5−85
Group B59
STATE STANDARD OF THE USSR
ALLOYS AND MASTER ALLOYS BASED ON VANADIUM
Method of determination of manganese
Vanadium base alloys and alloying elements. Method for determination of manganese
AXTU 1209*
________________
* Probably, the error of the original. Should read AXTU 1709. — Note the manufacturer’s database.
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 specifies the titrimetric method for the determination of manganese (50 to 75%) in binary alloys of the vanadium and manganese.
The method is based on oxidation of manganese in a mixed semiochemicals environment before pneumococcal condition neccersarily ammonium in the presence of a catalyst (nitrate of silver) and the titration of manganese acid oxalic acid.
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 26473.0−85.
2. APPARATUS, REAGENTS AND SOLUTIONS
Analytical scale.
Libra technical.
Tile electric.
Conical flasks with a capacity of 250 cm.
Volumetric flasks with a capacity of 100 cm, 1 DM.
Pipettes with a capacity of 5 and 10 cmwith divisions.
Burette with a capacity of 25 cmwith a scale division of 0,05 cm.
Measuring beakers with a capacity of 25 and 100 cm.
Sulfuric acid GOST 4204−77, diluted 1:1.
Nitric acid GOST 4461−77.
Orthophosphoric acid according to GOST 6552−80.
Oxalic acid, a solution of molar concentration of the equivalent 0,1 mol/DM(in the reduction reaction of manganese in an acidic environment); preparing of standard-titer, 0.1 N.
Silver nitrate according to GOST 1277−75, solution concentration of 2.5 g/DM.
Ammonium neccersarily according to GOST 20478−75, solution concentration of 200 g/DM.
3. ANALYSIS
A portion of the sample weighing 0.5 g was placed in a conical flask with a capacity of 250 cm, pour 15−20 cmof sulfuric acid solution, dissolve while heating, add 1−2 cmof the solution of nitric acid, evaporated to fumes of sulfuric acid, cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water, mix.
In a conical flask with a capacity of 250 cmpipetted 5−3 cmof sample solution containing about 0.01 g of manganese, poured 100 cmwater 7 cmof a solution of phosphoric acid and 10 cmof a solution of silver nitrate, the solution is heated to 80−90 °C, pour 10 cmof a solution of ammonium naternicola, kept the sample solution at 50−60 °C for 25−30 min, then boil until the termination of allocation of small bubbles. The solution was cooled to 60−70 °C and slowly titrated manganese with a solution of oxalic acid until the disappearance of the pink color.
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of manganese () in percent is calculated by the formula
,
where is the volume of solution of oxalic acid consumed for titration, cm;
— capacity volumetric flasks, cm;
— aliquotes volume of the solution taken for titration, cm;
0,001099 — mass concentration of solution of oxalic acid, expressed in g/cmof manganese;
— the weight of the portion of the sample,
4.2. The values of permissible differences given in the table.
Mass fraction of manganese, % |
Allowable difference, % |
50,0 | 1,1 |
75,0 |
1,7 |
(Changed edition, Rev. N 1).