GOST 3240.14-76
GOST 3240.14−76 magnesium Alloys. Method for the determination of neodymium (Change No. 1)
GOST 3240.14−76
Group B59
INTERSTATE STANDARD
MAGNESIUM ALLOYS
Method for the determination of neodymium
Magnesium alloys.
Method for determination of neodymium
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 |
Section number, paragraph |
| GOST 8.315−97 |
Sec. 5 |
| GOST 804−93 |
Sec. 2 |
| GOST 3118−77 |
Sec. 2 |
| GOST 3240.0−76 |
1.1 |
| 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 specifies spectrometric method for the determination of neodymium (for the mass concentration of neodymium from 1.0 to 5.0%).
The method is based on measuring the optical density of hydrochloric acid solutions containing the Aqua ions of neodymium.
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 3240.0.
2. APPARATUS, REAGENTS AND SOLUTIONS
Spectrophotometer.
Hydrochloric acid according to GOST 3118, diluted 1:1 and 2:1.
The oxide of neodymium.
Standard solution of neodymium: 11,6600 g calcined in a muffle furnace at (900±10) °C to constant mass of oxide of neodymium was dissolved with heating in 50 cmof hydrochloric acid diluted 1:1, transferred to a volumetric flask with a capacity of 250 cm
and dilute to the mark with water.
1 cmof the solution contains 0.04 g of neodymium.
Primary magnesium ingots according to GOST 804 in the form of chips.
(Changed edition, Rev. N 1).
3. ANALYSIS
3.1. A portion of the alloy mass of 4 g is dissolved in 100 cmof hydrochloric acid, diluted 2:1, transferred into a volumetric flask with a capacity of 100 cm
, made up to the mark with water, mix and filter for photometry.
The solution was transferred to a cuvette thickness of the absorbing layer of 10 cm and measure the optical density at 
) is calculated by the formula
3.2. Construction of calibration curve
In a series of batches of 4 g of magnesium is added from microburette standard solution neodymium 0; 0,5; 1,0; 2,0; 2,5; 3,0 and 5.0 cm, which corresponds to 0; 0,02; 0,04; 0,08; 0,10; 0,12 and 0.20 g of neodymium. Dissolved in 100 cm
of hydrochloric acid of 2:1, under low heat, transferred to volumetric flasks with a capacity of 100 cm
, is diluted to the mark with water and mix. Solutions spectrophotometric as specified in claim 3.1. The results of optical density measurements to build a calibration curve, plotting on the x-axis mass fraction of neodymium in grams and the y — axis the intensity of the absorption bands of the Aqua ions of neodymium.
Sec. 3. (Changed edition, Rev. N 1).
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of neodymium () in percent is calculated by the formula
where is the mass of neodymium, was found in the calibration schedule g;
— the weight of the portion of alloy,
4.2. Allowable absolute differences of the results of the parallel definitions should not exceed the values given in the table.
| The mass fraction of neodymium, % |
The absolute allowable difference, % |
| From 1.0 to 2.0 |
0,04 |
| SV. Of 2.0 to 5.0 |
0,1 |
Sec. 4. (Changed edition, Rev. N 1).
5. CONTROL OF MEASUREMENT ACCURACY
To control the accuracy of measuring the mass fraction of neodymium from 1.0 to 5.0% using the state standard samples of magnesium alloys, as well as 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 control the accuracy of measuring the mass fraction of neodymium by a method of additives.
Sec. 5. (Added, Rev. N 1).
