This standard specifies the determination method of hydrogen content in tantalum and niobium. This standard is applicable to the determination of hydrogen content in tantalum and niobium. Determination range: 0.005% to 0.06%. GB/T 15076.15-1994 Chemical analysis method for tantalum and niobium Determination of hydrogen content GB/T15076.15-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical Analysis Methods of Tantalum and Niobium-Determination of Hydrogen Content
Methods for Chemical Analysis of Tantalum and Niobium-Determination of Hydrogen Content1 Subject Content and Scope of Application
This standard specifies the method for determining the hydrogen content in tantalum and niobium. This standard is applicable to the determination of hydrogen content in tantalum and niobium. Determination range: 0.0005%~~0.06%. 2 Reference Standards
GB1.4 Guidelines for Standardization Work Provisions for the Preparation of Chemical Analysis Methods GB1467 General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products 3 Principles of the Method
GB/T15076.15-94
Under the flow of fluorine carrier gas, the sample is heated and melted in a graphite crucible, hydrogen is thermally decomposed and released, separated from other components by a chromatographic column, and detected by a thermal conductivity cell detector. The hydrogen content is calculated based on the peak value of the hydrogen chromatogram. 4 Reagents and materials
4.1 Molecular sieve: particle size 315~450m, 5A or other models. 4.2 Nickel box: thickness not more than 0.05mm, hydrogen content not more than 0.0002%. 4.3 Argon: purity greater than 99.99%.
4.4 Standard samples of hydrogen-containing button and saw: no less than two (different contents). 4.5 Graphite: made of high-density, high-strength pure graphite, shape and size refer to Figure 1. Approved by the State Administration of Technical Supervision on May 9, 1994 544
Implementation on December 1, 1994
5 Instruments
GB/T15076.15--94
Figure 1 Shape of graphite
The pulse heating gas chromatograph consists of two parts: the pulse heater and the gas chromatograph. The heating furnace temperature of the pulse heater should be higher than 3000℃. Sensitivity of gas chromatograph: The unit hydrogen chromatographic peak is equivalent to the amount of hydrogen should not be greater than 0.025μg: Stability: The baseline fluctuation in 5 minutes is not greater than 0.2mV.
The gas flow diagram of the instrument is shown in Figure 2.
Figure 2 Gas flow diagram
1-Carrier gas source; 2-Purification pipe, 3-Pressure regulating valve: 4 Pressure gauge 5 Needle valve; 6-Chromatographic column; 7-Thermal conductivity cell: 8-Rotameter, 9-Switch valve; 10 Constant temperature box; 11-Normal closed solenoid valve; 12-Normal open solenoid valve; 13-Buffer bottle; 14-Sample adder; 15---Pulse furnace; 16-Degassing source 545
6 Sample
6.1 Powdered laboratory samples are wrapped with nickel foil. GB/T 15076. 1594
6.2 Block and filament laboratory samples are made into the required shape, washed with anhydrous alcohol and carbon tetrachloride, and blown dry. 7 Analysis steps
7.1 Determination quantity
Weigh 3 samples, measure them independently, and take the average value. 7.2 Test material
Weigh the sample according to Table 1, accurate to 0.0001g. Table 1
Hydrogen content, %
0. 000 5 ~~ 0. 001 0
0. 001 0~0. 005 0
>0.005 0～0. 010
>0. 010~0. 060
Sample·g
0. 500 0~~0. 250 0
0. 250 0 ~ 0. 150 0
0. 150 0 ~0. 100 0
-0,050 0
7.3, According to the sample analysis procedure and the same conditions as the test sample, measure the blank twice continuously and take the average value, which shall not be greater than 1μg. 7.4 Calibration test
7.4:1 Under the same analytical conditions as the test sample, determine the standard sample (4.4), and calculate the hydrogen standard correction coefficient K according to (1): m, xc.
100(h, -h.)
where; K-
unit chromatographic peak equivalent to the mass of hydrogen, g/mn, - mass of the standard sample, g;
C-percentage of hydrogen in the standard sample;
h.~-peak value of hydrogen obtained by measuring the standard sample, mmho--peak value of hydrogen obtained by measuring the blank, mm. Measure three times independently and calculate the average value.
The peak area can be used for quantification.
7.4.2 Use another standard sample to verify the analysis. The absolute value of the difference between the measured result and the standard value shall not be greater than the corresponding standard allowable difference. 7.5 Determination
7.5.1 Connect the power, gas and water supply of the instrument and make it stable under the analytical conditions of the sample before the determination can be carried out. 7.5.2 Place the sample in the sampler.
7.5.3 Place the graphite in the pulse furnace for high-temperature degassing and flushing for 20 seconds. (1)
7.5.4 Switch the pulse furnace to the analytical gas path, place the sample in the graphite, pulse heat and melt, and the released hydrogen is directly introduced into the chromatograph by the carrier gas for separation and detection, and the hydrogen chromatographic value is measured. The analytical conditions are shown in Table 2.
Heating voltage, Vwww.bzxz.net
Heating current, A
Calculation and expression of analysis results
Calculate the percentage of hydrogen according to formula (2):
Wherein: h-
GB/T 15076.15-94
Heating time
The peak value of hydrogen obtained by measuring the sample, mm;
h. —-The peak value of hydrogen obtained by measuring the blank, mm;-The standard correction coefficient of hydrogen + g/mm;
m——The mass of the sample, 8.
It can be quantified by peak area.
Carrier gas flow rate
mL/min
K×(h-ho)
Pressure before column
X100 ..·
The result should be expressed to 3 decimal places. If the hydrogen content is less than 0.01%, it should be expressed to 4 decimal places. Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 3. Table 3
0. 000 5~0.001 0
0. 001 0~0. 005 0
>0. 005 0~~0. 010
>0.010~0.060
Additional remarks:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Ningxia Nonferrous Metals Smelting Co., Ltd. This standard was drafted by Zhuzhou Cemented Carbide Co., Ltd. The main drafters of this standard are Wang Shuifa and He Kehong. Supplement
From the date of implementation of this standard, the former Ministry of Metallurgical Industry of the People's Republic of China issued the Ministry of Standard YB942 (7) -78 "Determination of Hydrogen Content in Molybdenum and Saw (Vacuum Fusion-Gas Chromatography)" will be invalid. 547
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