GB/T 5686.5-1988 Chemical analysis methods for manganese silicon alloys - Determination of carbon content by infrared absorption method

This standard is applicable to the determination of carbon content in manganese silicon alloy. Determination range: 0.025% ~ 4.000%. This standard complies with GB 1467-78 "General Principles and General Provisions of Chemical Analysis Methods for Metallurgical Products". GB/T 5686.5-1988 Chemical Analysis Method for Manganese Silicon Alloy Determination of Carbon Content by Infrared Absorption Method GB/T5686.5-1988 Standard Download Decompression Password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method of silicomanganese alloy
Determination of carbon content by infrared absorption method
Methods for chemical analysis of silicomanganese alloyThe intrared absorption method for thedetermination of carbon contentThis standard is applicable to the determination of carbon content in silicomanganese alloy. Determination range: 0.025%~4.000%UDC 669.74° 782
：543.062
GB 5686.5—88
This standard complies with GB1467-78 "General Principles and General Provisions of Standards for Chemical Analysis Methods of 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 specific wavelength. 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 perfluorate: Anhydrous, granular.
2.3 Caustic asbestos: Granular.
2.4 Glass wool.
2.5 Tungsten particles: The carbon content is less than 0.002%, and the particle size is 0.8~1.4mm. 2.6
Tin particles: The carbon content is less than 0.002%, and the particle size is 0.4~～0.8mm. If necessary, the surface should be cleaned with acetone (2.1) and dried at room temperature.
Pure iron: The carbon content is less than 0.002%.
2.8 Oxygen: The purity is greater than 99.95%. Other grades of oxygen can also be used if a low and consistent blank can be obtained. 2.9 Power source: Nitrogen or compressed air, with an impurity (water and oil) content of less than 0.5%. 2.10 Quality crucible: Φ×h, mm: 23×23 or 25×25, and burned in a high temperature furnace above 1200℃ for 4h or burned with oxygen until the blank value is the lowest.
2.11 Crucible clamp.
3 Instruments and equipment
3.1 Infrared absorption carbon determination instrument (sensitivity is 1.0ppm) The device is shown in the figure.
Approved by the Ministry of Metallurgical Industry of the People's Republic of China on February 2, 1988 28.1
Implemented on March 1, 1989
GB5686.5-
1—Oxygen cylinder; 2—Two-stage pressure regulator; 3—Gas washing bottle, 4, 9—Drying tube, 5—Pressure regulator; 6—High induction furnace; 7—Combustion tube; 8—Dust collector; 10—Flow controller; 11—Converter for converting carbon dioxide 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 perchlorate (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 power gas (nitrogen or compressed air), a two-stage pressure regulator and a timing control part to ensure the provision of appropriate pressure and rated flow.
3.3 The high-frequency 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.
3.4.2 The control functions include automatic loading and unloading of crucibles and furnace lifting, 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
It is mainly composed of an electronic balance (sensitivity not greater than 1.0mg) controlled by a microprocessor, an infrared analyzer and electronic measuring elements. 4 SamplesbzxZ.net
All samples should pass through a 0.125mm sieve.
5 Analysis steps
5.1 Sample quantity
Weigh 0.200g of sample.
5.2 Blank test
GB 5686.5-88
Weigh 0.800±0.005g of pure iron (2.7) and place it in a crucible (2.10) pre-filled with 0.300±0.005g of tin particles (2.6), cover it with 1.500±0.005g of tungsten particles (2.5), and measure it according to 5.5 on the same range or channel. Repeat enough times until a low and relatively consistent reading is obtained. Record the minimum three readings, calculate the average value, and refer to the instrument manual to enter the average value into the analyzer. 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 0.500g of standard samples with a carbon content of about 0.050%, and measure according to 5.5. The result fluctuation 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 fluctuation of the measured results should be within the allowable difference 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 For different ranges or channels, their blank values ​​should be measured and calibrated respectively. 5.4.3 When the analysis conditions change, such as when the instrument has not been preheated for 1 hour, and the blank value of the oxygen source, crucible or flux has 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 analysis conditions of the instrument: such as the combustion integration time of the instrument, the setting of the comparison level (or set number), etc.
5.5.2 Place the weighed sample (5.1) in a crucible (2.10) pre-filled with 0.300g tin particles (2.6), cover it with 0.800g pure iron (2.7) and 1.500g tungsten particles (2.5), take the crucible with tongs and place it on the crucible seat on the furnace table, 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
>0.070～0.120
>0.120~0.400
>0.400~1.200
>1. 200~2. 500
>2. 50~4. 00
Additional remarks:
This standard was drafted by Xinyu Iron and Steel Plant.
The main drafters of this standard are Wu Taibai and Wu Fangcheng. GB5686.5-88
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB79-65 "Chemical Analysis Method of Manganese Silicon Alloy" shall be invalid. 287
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.