GOST 3240.18-76
GOST 3240.18−76 magnesium Alloys. Method of determining titanium (with Change No. 1)
GOST 3240.18−76
Group B59
INTERSTATE STANDARD
MAGNESIUM ALLOYS
Method of determining titanium
Magnesium alloys.
Method for determination of titanium
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
3. INTRODUCED FOR THE FIRST TIME
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Item number |
| GOST 8.315−97 |
Sec. 5 |
| GOST 3118−77 |
Sec. 2 |
| GOST 3240.0−76 |
1.1 |
| GOST 17746−96 |
Sec. 2 |
| GOST 25086−87 |
Sec. 5 |
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 photometric method for the determination of titanium (with a mass fraction of titanium from 0.001 to 0.02%).
The method is based on the interaction of in hydrochloric acid medium titanium diantipyrylmethane with the formation of a Golden-yellow complex compound, the color intensity being proportional to the titanium content. The interfering influence of iron can be eliminated by adding ascorbic acid.
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 3240.0.
2. APPARATUS, REAGENTS AND SOLUTIONS
Type photoelectrocolorimeter FEK-56, or FEK 60.
Hydrochloric acid according to GOST 3118, diluted 1:1, 10% solution.
Titanium sponge according to GOST 17746 grade TG-100.
Ascorbic acid, 10% solution.
Diantipyrylmethane, 1% solution; prepared as follows: 10 g diantipyrylmethane dissolved in 300−400 m of a 10% solution of hydrochloric acid, filtered in a volumetric flask with a capacity of 1 DM, adjusted to the mark with 10% hydrochloric acid and stirred.
Standard solutions of titanium
Solution A, prepared as follows: 0.1 g of titanium sponge was dissolved in 20 m sulphuric acid, diluted 1:1, is oxidized by adding dropwise nitric acid to the discoloration and boil to remove oxides of nitrogen. The solution was cooled, transferred to a volumetric flask with a capacity of 1 DMand diluted with distilled water to the mark.
1 cmof the solution contains 0.0001 g of titanium.
Solution B is prepared as follows: 100 smsolution And transferred into a measuring flask with a capacity of 1 DM
, is added 20 cm
of sulphuric acid diluted 1:1, and diluted to the mark with water.
1 cmof solution B contains 0,00001 g of titanium.
(Changed edition, Rev. N 1).
3. ANALYSIS
3.1. A portion of the alloy is 1 g (if the mass fraction of titanium up to 0.01%) and 0.5 g (when the mass fraction of titanium from 0.01 to 0.02%) is dissolved in 30 cmof hydrochloric acid diluted 1:1, and heated to complete dissolution of the alloy. The solution was cooled, poured into a volumetric flask with a capacity of 100 cm
and, if necessary, filtered. Then add 2 cm
of a 10% solution of ascorbic acid, 3−5 min 10 cm
of hydrochloric acid diluted 1:1, and 25 cm
diantipyrylmethane solution, made up to the mark with water and mix well, then leave for the full development of colour within 2 h. the Optical density of the solution measured at
Mass fraction of titanium is determined according to the calibration schedule.
3.2. Construction of calibration curve
In a series of volumetric flasks with a capacity of 100 cmplaced 0,0; 0,5; 1,0; 3,0; 5,0; 7,0; 9,0 and 10.0 cm
standard solution B, which corresponds to 0; 0,5·10
; 1·10
; 3·10
; 5·10
; 7·10
; 9·10
and 1·10
g of titanium, is added to 15 cm
of hydrochloric acid, diluted 1:1,2 cm
of ascorbic acid and 25 cm
diantipyrylmethane. The solution was topped to the mark with water, mixed well and after 2 h, measure the optical density of the solution, as stated in claim 3.1. The values of optical density calibration curve building.
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of titanium () in percent is calculated by the formula
where is the mass of titanium, was found in the calibration schedule g;
— the weight of the portion of alloy,
(Changed edition, Rev. N 1).
4.2. Allowable absolute differences of the results of the parallel definitions should not exceed the values given in the table.
| Mass fraction of titanium, % |
The absolute allowable difference, % |
| From 0.001 to 0.005 |
0,0005 |
| SV. 0,005 «0,01 |
0,001 |
| «0,01» 0,02 |
0,002 |
5. CONTROL OF MEASUREMENT ACCURACY
To control the accuracy of measuring the mass fraction of titanium from 0.001 to 0.02% 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 monitor the accuracy of measurements of mass fraction of titanium additives.
Sec. 5. (Added, Rev. N 1).
