This standard is applicable to the determination of carbon content in ferrotitanium. Determination range: 0.010% to 0.400%. This standard complies with GB 1467-78 "General Principles and General Provisions for Chemical Analysis Methods of Metallurgical Products". GB/T 4701.8-1988 Chemical analysis method for ferrotitanium - Determination of carbon content by infrared absorption method GB/T4701.8-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method of ferrotitanium
Methods for chemlcal analysls of ferrotitaniumThe inErared absorption method for the determinatlonof carbon content
This standard is applicable to the determination of carbon content in ferrotitanium. Determination range: 0.010%～0.400%. UDC 669. 15' 295
GB 4701.8—88
This standard complies with GB1467-78 "General Principles and General Provisions of Chemical Analysis Methods for Metallurgical Products". 1 Method Summary
The sample is heated and burned in the oxygen flow of a high-frequency induction furnace. The generated carbon dioxide is carried by oxygen to the measuring chamber of the infrared analyzer. Carbon dioxide absorbs infrared energy of a certain wavelength, and its absorption energy is proportional to its concentration. The carbon content can be measured according to the change in the energy received by the detector. 2 Reagents and materials
2.1 Acetone: The carbon content of the residue after evaporation is less than 0.0005%. 2.2 Magnesium perchlorate: anhydrous, granular.www.bzxz.net
2.3 Caustic soda asbestos: granular.
2.4 Glass wool.
2.5 Tungsten granules: The carbon content is less than 0.002%, and the particle size is 0.8~1.4mm. 2. 6 Tin particles: carbon content less than 0.002%, particle size 0.4~0.8mm. If necessary, clean with ketone (2.1) and dry at room temperature. 2.7 Oxygen: purity greater than 99.95%. Other levels of oxygen can also be used if a low and consistent blank can be obtained. 2.8 Power source: nitrogen or compressed air, with impurities (water and oil) less than 0.5%. 2. Daily quality: ×h, mm: 23×23 or 25×25, and burn in a high-temperature heating furnace above 1200℃ for 4h or burn with oxygen until the air volume value is the lowest.
2.10 Crucible tongs.
3 Instruments and equipment
3.1 Infrared absorption carbon determination instrument (sensitivity is 1.0ppm) The device is as shown in the figure below.
Approved by the Ministry of Metallurgical Industry of the People's Republic of China on February 2, 1988 and implemented on March 1, 1989
GB 4701. 8 — 88
1—oxygen cylinder, 2—two-stage pressure regulator; 3—gas washing bottle; 4.9—drying tube 5 pressure regulator: 6—high-frequency induction furnace; 7—combustion tube; 8—dust collector; 10—flow controller; t1—converter for converting phosphorus oxide into carbon dioxide, 12—desulfurizer; 13—carbon dioxide infrared detector 3.1.1 Gas washing bottle (3) contains caustic soda asbestos (2.3). 3.1.2 Drying tube (4, 9): contains magnesium perfluoride (2.2). 3.2 Gas source
3. 2. 1 The carrier gas system includes an oxygen container, a two-stage pressure regulator and a timing control part to ensure the provision of appropriate pressure and rated flow. 3.2.2 The power gas source system includes a two-stage pressure regulator for power gas (nitrogen or compressed air) and a timing control part to ensure the provision of appropriate pressure and rated flow.
3.3 The high-particle induction furnace
should meet the requirements of the melting temperature of the sample.
3.4 ​​Control system
3.4.1 The microprocessor system includes a central processing unit, a memory, a keyboard input device, an information center display screen, an analysis result display screen and an analysis result printer, etc.
3.4.2 The control functions include automatic loading and unloading of scale and furnace lifting and lowering, automatic cleaning, analysis condition selection and setting, monitoring of the analysis process and alarm interruption, collection, calculation, correction and processing of analysis data, etc. 3.5 Measurement system
Mainly composed of an electronic balance (sensitivity not greater than 1.0 mg) controlled by a microprocessor, an infrared analyzer and electronic measuring elements. 4 Sample
All samples should pass through a 0.125 mm sieve. 5 Analysis steps
5.1 Sample quantity
Weigh 0.500 g of sample.
5.2 Blank test
GB 4701. 8 --88
Weigh 0.500 g of a low-carbon (carbon content less than 50 ppm) standard sample of the same type as the sample to be tested (if there is no standard sample of the same type, other steel standards with similar composition can be selected), put it in a crucible (2.9) pre-filled with 0.500 ± 0.0058 tin particles (2.6), cover it with 1.500 ± 0.0058 tungsten particles (2.5) in the same range or channel, and measure according to 5.5. Repeat enough times until a low and accurate reading is obtained. The blank value should be equal to the difference between the measured carbon content and the known carbon content of the standard sample. Record the three minimum readings, calculate the average value, and enter the average value into the analyzer with reference to the instrument manual. The instrument will then perform electronic compensation for the blank value when measuring the sample. 5.3 Analysis Preparation
5.3.1 Debug and check the instrument according to the instrument manual to ensure that the instrument is in a normal and stable state. 5.3.2 Select and set the best analysis conditions.
5. 3.3 Use standard samples and flux to perform two test tests according to 5.5.1 and 5.5.2 to determine whether the instrument is normal. 5.3.4 Weigh several portions of 0.500 standard samples with a carbon content of about 0.05%, and measure them according to 5.5. The result should be within the range of ±0.003%, otherwise the sensitivity of the instrument should be adjusted according to the instrument requirements. 5.4 Calibration test
5.4.1 According to the carbon content of the sample to be tested, select the corresponding range or channel, and select three standard samples of the same type (the carbon content of the sample to be tested should fall within the range of the carbon content of the selected three standard samples). Perform calibration in sequence, and the passiveness of the measured results should be within the allowable error range to confirm the linearity of the system, otherwise the linearity of the system should be adjusted according to the instrument manual. 5.4,2 Different ranges or channels should measure their blank values ​​and calibrate them respectively. 5.4.3 When the analytical conditions change, such as the instrument has not been preheated to 1h, and the blank values ​​of the oxygen source, crucible or flux have changed, it is required to re-measure the blank and calibrate.
5.5 Determination
5.5.1 According to the carbon content range of the sample to be tested, select the best conditions of the instrument respectively: such as the combustion integration time of the instrument, the setting conditions of the comparison level (or set number).
5.5.2 Place the weighed sample (5.1) in (2.9) which has been pre-filled with 0.500g of tin particles (2.6), covering 1.500g of particles (2.5), take the crucible with tongs and place it on the stove, operate according to the instrument manual, start analysis and read the results. 6 Allowable Difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. %
>0. 025~ 0.070
Additional Notes:
Additional Chapter
This standard was drafted by Jilin Ferroalloys.
The main drafter of this standard is Chang Yanfu.
>0. 070~0.120
>0. 120 ~0. 400
Allowance
From the date of implementation of this standard, the original metallurgical industry department standard YB 581-65 titanium nitrate chemical analysis method> will be invalid. This standard level mark GB4701.8-881
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