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GOST 12344-2003

GOST 12344−2003 Steel alloyed and high alloy. Methods for determination of carbon

GOST 12344−2003

Group B39

INTERSTATE STANDARD

STEEL ALLOYED AND HIGH-ALLOYED

Methods for determination of carbon

Alloyed and high-alloyed steels. Methods for determination of carbon

ISS 77.040.30
AXTU 0709

Date of introduction 2004−09−01

Preface

1 DEVELOPED by the Russian Federation, the Interstate technical Committee for standardization MTK 145 «monitoring Methods of steel products"

INTRODUCED by Gosstandart of Russia

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 23 dated 22 may 2003). Was standards Bureau MGS N 4451

The adoption voted:

The name of the state
The name of the national authority for standardization
Azerbaijan Azstandart
The Republic Of Armenia
Armastajad
The Republic Of Belarus Gosstandart Of The Republic Of Belarus
Georgia Gosstandart
Kazakhstan Gosstandart Of The Republic Of Kazakhstan
The Kyrgyz Republic Kyrgyzstandard
The Republic Of Moldova Moldovastandart
Russian Federation Gosstandart Of Russia
The Republic Of Tajikistan Tajikstandart
Turkmenistan The MDCSU „Turkmenstandartlary"
Uzbekistan
Uzstandard
Ukraine
Gosstandart Of Ukraine

3 Annex a of this standard corresponds to international standard ISO 9556:1989* „Steel and cast iron. Determination of the mass fraction of total carbon. The method of infrared absorption spectroscopy after combustion of the sample in the induction furnace“ in terms of the propagation of the essence of the method and sampling
________________
* Access to international and foreign documents referred to here and hereinafter, can be obtained by clicking on the link. — Note the manufacturer’s database.

4 Resolution of the State Committee of the Russian Federation for standardization and Metrology on January 20, 2004 N 24 St interstate standard GOST 12344−2003 introduced directly as a national standard of the Russian Federation from September 1, 2004

5 REPLACE GOST 12344−88

The re-release (as of April 2008)

1 Scope

This standard sets the coulometric method for the determination of carbon (with mass fraction of carbon from 0.002% to 2.00%) and the method of infrared spectroscopy (at a mass fraction of carbon from 0.001% to 2.00%) in the alloy and high-alloy steels.

Allowed determination of carbon by infrared absorption spectroscopy according to the international standard ISO 9556:1989, are given in Appendix A.

2 Normative references

The present standard features references to the following standards:

GOST 546−2001 copper Cathodes. Specifications

GOST 860−75 Tin. Specifications

GOST 2603−79 Acetone. Specifications

GOST 4470−79 of Manganese (IV) oxide. Specifications

GOST 5583−78 (ISO 2046−73) Oxygen gas technical and medical. Specifications

GOST 9147−80 Glassware and equipment lab porcelain. Specifications

GOST 13610−79 carbonyl Iron radio. Specifications

GOST 16539−79 Copper (II) oxide. Specifications

GOST 28473−90 Iron, steel, ferroalloys, chromium and manganese metal. General requirements for methods of analysis

3 General requirements


General requirements for methods of analysis GOST 28473.

4 Coulometric method for determining carbon

4.1 the essence of the method

The method is based on the combustion of a sample of steel in a current of oxygen in presence of flux at a temperature of 1300 °C — 1400 °C, the absorption of the formed carbon dioxide absorption by a solution with a particular initial pH value and subsequent measurement (in the apparatus for coulometric titration) the amount of electricity spent to restore the original pH value, which is proportional to the mass fraction of carbon in the linkage sample.

4.2 Instrument

The installation for determining the mass fraction of carbon by coulometric method (figure 1).

Figure 1 Coulometric installation

ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода

1 — oxygen tank (with a purity not less than 95%) according to GOST 5583 (use oxygen from coloradobased); 2, 3 — reducers, lowering the pressure of the oxygen; 4 — rotameter with pneumatic regulation of the flow of oxygen (from 0.2 to 2.0 DMГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода/min); 5 — tube refractory mullite designed for burning of sample; 6 — tube furnace, providing temperatures up to 1400 °C; 7 — absorber filter, filled with cotton wool for cleaning the products of combustion from the solid particles of oxides; 8 — gauge Express analyzer; 9 — electrode pair of the pH-meter; 10 — autoregulated device coulometric titration; 11 — digital display; 12 — anode compartment sensor; 13 — plastic partition between the sensors; 14 — cathode compartment sensor; 15 — tube refractory mullite designed for hot cleaning of oxygen (in the determination of carbon with a mass fraction of more than 0.03% hot cleaning oxygen can not be used); 16 — column filled with oscarito to clean oxygen from carbon dioxide

Figure 1 Coulometric installation


Allowed the use of installations of any type, including complete with automatic weights (correction mass), providing the accuracy of the analysis required by this standard.

When you use automatic weights the measurement error of the mass of sample should not exceed ±0.001 g.

Boat porcelain with GOST 9147 or other normative document, pre-calcined in flowing oxygen at operating temperature.

In the determination of carbon less than 0.05% pumps calcined directly before analysis, cooled to room temperature and stored in a desiccator.

Tubular resistance furnace, providing temperatures up to 1400 °C allows the use of induction furnaces.

Hook made of heat-resistant low-carbon steel with a length of 300−600 mm, a diameter of 3−5 mm.

4.3 Reagents and solutions

Absorption and support solutions in accordance with the type of the used coulometric setup.

Marshes carbonyl iron radio GOST 13610, OS.CH., tin GOST 860, the copper oxide according to GOST 16539, copper metal according to GOST 546.

Allowed the use of other flooded areas.

Ethers: sulphuric acid (medical) or diethyl ether.

Allowed to use other volatile organic solvents: acetone according to GOST 2603, chloroform.

Manganese dioxide according to GOST 4470.

Gidroperit.

4.4 Preparation for assay

Before analysis the installation of a drive in accordance with the instructions supplied with the device.

Before starting work, and after replacement of the mullite tubes burn two or three arbitrary linkage of steel with a mass fraction of carbon of 1.00%.

In determining the carbon materials with a high mass fraction of sulphur (free-cutting steel) to eliminate the effect of sulfur dioxide used manganese dioxide or gidroperit placed in the filter-absorber 7.

The calibration of an instrument performed on standard specimens of carbon steel.

4.5 analysis

In the analysis of alloy steels in the weight of steel weight of 0.25−0.50 g (depending on the mass fraction of carbon in steel and its chemical composition) of calcined placed in a porcelain boat and added 0.5−1.0 g of copper or iron or any other beach.

In the analysis of high-alloyed steels used 1.5 g of a mixture of marshes, consisting of tin and iron or oxides of copper and iron taken in both cases in a ratio of 1:2.

When the mass fraction of carbon in the steel less than 0.20% of the portion recommended to be washed with ether or other volatile organic solvent and air dry.

The boat with the charge of metal and flux is placed in the most heated portion of the porcelain tube, which quickly closed the metal gate: press the button „reset“, while the indicator digital display set to „zero“.

In the burning process of mounting the metal on the digital display there is a continuous expense.

The analysis is considered complete if the reading on the display does not change within one minute, or changes to the value of the idling score of the instrument.

For making the appropriate corrections in the result of sample analysis spend control experience. For this purpose calcined in a porcelain boat is placed corresponding to the flux and burn it at operating temperature during time spent on the burning of the sample of the analyzed material. The duration of the measurement (combustion of sample metal) is 1.5−3 min depending on the chemical composition of the analyzed material.

4.6 processing of the results

4.6.1 the Mass carbon fraction ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, %, is calculated by the formula

ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, (1)


where ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода — the weight of the portion in which the calibrated device, g;


ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода — the readings obtained from the combustion of a sample of analyte material, %;

ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода — arithmetic mean value of the readings obtained from the combustion of the beach, when conducting the reference experiment, %;

ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода — the mass of the analyzed sample metal,

When using the device with automatic weights (correction mass) mass fraction of carbon ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, % calculated according to the following formula

ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода. (2)

4.6.2 Regulations operational control of convergence, reproducibility, and accuracy of determining the mass fraction of carbon is given in table 1.

Table 1

Percentage

Mass fraction of carbon

The ultimate accuracy of the analysis results ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода

The standard operational control of convergence ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода

The standard operational control
convergence ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода

The standard operational control of reproducibilityГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода

The standard operational control precision ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода

From 0,001 to 0,002 incl.
About 0.0006
0,0007
0,0008
0,0008
0,0004
SV. 0,002 0,005 » 0,0008
0,0008
0,0010
0,0010
0,0005
" 0,005 " 0,010 «
0.0016 inch
0,0017
0,0020
0,0020
0,0010
» 0,010 " 0,020 «
0,003
0,003
0,004
0,004
0,002
» 0,020 " 0,050 «
0,005
0,005
0,006
0,006
0,003
» 0,050 " 0,10 «
0,008
0,008
0,010
0,010
0,005
» 0,10 " 0,20 «
0,012
0,012
0,015
0,015
0,008
» 0,20 " 0,50 «
0,016
0,017
0,020
0,020
0,010
» 0,50 " 1,0 «
0,024
0,025
0,030
0,030
0,016
» 1,0 " 2,0 «
0,04
0,04
0,05
0,05
0,03



Standards of operational control of convergence and standards for control of reproducibility is calculated at the confidence level ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода. Standards of operational control precision is calculated at the confidence level ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода.

5 Infrared absorption method for the determination of carbon

5.1 the essence of the method

The method is based on the combustion of a sample of steel in a current of oxygen in presence of flux at a temperature of 1700 °C and determining the quantity of formed carbon dioxide by measuring its absorption of infrared radiation.

5.2 Apparatus and reagents

Any type of automatic analyzer, based on the principle of absorption of infrared radiation and to ensure the accuracy of the analysis required by this standard.

Ether sulfate (medical). Allowed to use other volatile organic solvents: acetone, chloroform, etc.

The smoother used depending on the type of the used analyzer.

5.3 Preparation for assay

Before analysis the installation of a drive in accordance with the instructions supplied with the device.

The calibration of an instrument performed on standard specimens of carbon steel.

5.4 analysis

The analysis is carried out in accordance with the instructions supplied with the device.

When the mass fraction of carbon in the steel less than 0.20% of the portion recommended to be washed with ether or other volatile organic solvent and air dry.

For the relevant amendment to the result of the analysis carried out control experience.

The duration of the measurement (the burning of the sample metal) — 45 p

5.5 processing of the results

5.5.1 Mass fraction of carbon ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, % calculated according to the formula

ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, (3)


where ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода — the readings obtained by burning the sample of the analyzed material, %;

ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода — the readings obtained from the combustion of the beach, when conducting the reference experiment, %.

5.5.2 Standards of operational control of convergence, reproducibility, and accuracy of determining the mass fraction of carbon is given in table 1.

Annex a (mandatory). Steel and cast iron. Determination of the mass fraction of total carbon by infrared absorption spectroscopy after combustion of the sample in an induction furnace (ISO 9556:1989)

APPENDIX A
(required)

A. 1 Scope

This standard specifies an infrared absorption method for the determination of content of total carbon in steel and cast iron, after combustion of the sample in an induction furnace.

The method used in determining the mass fraction of carbon in the range of 0.003%-4,5%.

A. 2 Normative references

The present standard features references to the following standards:

GOST 1770−74 laboratory Glassware measuring glass. Cylinders, beakers, flasks, test tubes. General specifications

GOST 7565−81 (ISO 377−2-89) Iron, steel and alloys. Sampling method for determination of chemical composition

GOST 29169−91 (ISO 648−77) oils. Pipette with one mark

GOST 29251−91 (ISO 385−1-84) oils. Burette. Part 1. General requirements

A. 3 the essence of the method

The method is based on combustion in a high-frequency induction furnace in a current of oxygen in presence of flux at a high temperature and determining the quantity of the formed oxide or mixture of oxide and carbon dioxide by absorption in the infrared region.

A. 4 Reagents

In the analysis, except in cases otherwise specified, use reagents of known analytical purity and distilled water or water of equivalent purity.

A. 4.1 Water, free from carbon dioxide. Water boil for 30 min, cooled to room temperature and saturated with oxygen for 15 min. Prepare immediately before use.

A. 4.2, Oxygen purity not less than 99.5%. If oxygen is suspected the presence of organic compounds, their oxidation before the filter must be installed pipe with catalyst (dioxide of copper or platinum), heated to a temperature above 450 °C.

A. 4.3 Iron is a metal with a mass fraction of carbon at least 0,0010%.

A. 4.4 Solvent suitable for washing and drying samples, such as acetone.

A. 4.5 the rate of Magnesium Mg (ClOГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода)ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углеродаparticle size 0,7−1,2 mm.

A. 4.6 Barium carbonate, the content of the basic substance is not less than 99.9% (mass.). Before use it was dried at 105 °C — 110 °C for 3 h and cooled in a desiccator.

A. 4.7 Sodium carbonate, the content of the basic substance is not less than 99.9% (mass.). Before use it was dried at a temperature of 285 °C for 3 h and cooled in a desiccator.

A. 4.8 Plavni: metallic copper, a mixture of tungsten and tin or tungsten with a mass fraction of carbon at least 0,0010%.

A. 4.9 Sucrose, titrated solution: 14,843 g of sucrose (CГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углеродаHГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углеродаOГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода), previously dried at 100 °C — 105 °C for 2.5 h and cooled in a desiccator, weighed with an accuracy of 1 mg, dissolved in 100 ml of water (A. 4.1), transferred to a volumetric flask with a capacity of 250 ml, bring to mark and mix. 1 ml of this solution contains 25 mg of carbon.

A. 4.10 Sodium carbonate, titrated solution: 55,152 g of sodium carbonate (A. 4.7) is weighed with an accuracy of 1 mg, dissolved in 200 ml of water, transferred into a volumetric flask with a capacity of 250 ml, made up to the mark with water and mix. 1 ml of this solution contains 25 mg of carbon.

A. 4.11 Askari (asbestos impregnated with sodium hydroxide) particle size 0,7−1,2 mm.

A. 5 Instrument

In the analysis, if no other recommendations use only conventional laboratory equipment.

All glassware should be class A in accordance with GOST 1770, GOST 29169 host 29251.

The characteristics of manufactured industrial instrumentation is given in Appendix B.

A. 5.1 Pipette 100 ml capacity with a measuring error of not more than 1 ml.

A. 5.2 Capsule tin with a diameter of about 6 mm, height 18 mm, weight 0.3 g, volume of about 0.4 ml with a mass fraction of carbon not more than 0,0010%.

A. 5.3 Crucibles ceramic, can withstand temperatures of combustion in an induction furnace.

Before use, the crucible is calcined in an electric furnace in air or in an oxygen flow for 2 h at 1100 °C and stored in desiccator.

Note — When determining the mass fraction of carbon of less than 0,0010% is recommended to be heated crucibles at a temperature of 1350 °C in oxygen flow.

A. 6 Sampling

Sampling — according to GOST 7565 or other normative documents for the products.

A. 7 Methods of analysis

Security measures

The main danger associated with the possibility of burns, ignition crucibles and working with the melt. You should use special crucible tongs and containers for used cups.

When using oxygen cylinders should comply with the usual for this case precautions. After combustion of the sample, immediately remove the oxygen from the furnace, because the increased oxygen content in a confined space may cause fire and explosion.

A. 7.1 General requirements

For pre-cleaning of oxygen passed through a tube filled with Astarita (asbestos) impregnated with a solution of sodium hydroxide (A. 4.11) and the tube with the rate of magnesium (A. 4.5). To clean oxygen from dust use a filter of glass wool or stainless steel mesh that need to be cleaned or replaced as necessary. The combustion chamber, stand under the crucibles and filters are periodically cleaned by removing deposited oxides.

Each piece of equipment after its inclusion must be warmed within the time specified in the instructions to the device.

After cleaning of the combustion chamber, replacement or cleaning of filters, and after an interruption in operation of the device in order to stabilize the work necessary to carry out the burning of several samples, whose composition similar to the analyzed one.

Through the installation allow oxygen and set instrumentation on the zero mark. If the scale of the measuring device registers the mass fraction of carbon from the percent, you must configure the device for each area of the calibration. To do this, choose a standard sample with a mass fraction of carbon, close to the maximum calibration interval; carry out the analysis (as indicated in A. 7.4) and establish the certified value of the mass fraction of carbon on the measuring scale of the instrument.

Note — the Setting of the scale is carried out before the calibration specified in A. 7.4, it does not replace or adjusts itself in calibration.

A. 7.2 sample Preparation

Sample preparation — according to GOST 7565 or other normative documents for the products.

The analyzed sample is degreased by washing in appropriate solvent and dried to remove traces of solvent. Weigh approximately 1 g of the sample with an accuracy of 1 mg, in mass fractions of carbon, less than 1.00% or about 0.5 g in mass fractions of maximum of 1.00%.

Note — the weight of the portion may depend on the type of analyser used for analysis.

A. 7.3 Control experience

Before analysis you need to double-spend is described below the reference experience.

Tin capsule (A. 5.2) is placed in a ceramic crucible (A. 5.3) and slightly press it to the bottom of the crucible. Add pure iron (A. 4.3) in the amount corresponding to the sample test portion, and necessary to analyze the amount of flux (note 2 of this paragraph) and analyze as described in A. 7.4.

The obtained results are transferred using the calibration curve (A. 7.5) mass fraction of carbon and calculate the value of the reference experiment by subtracting the mass fraction of carbon in iron, of the found values.

The average value of the reference experiment is determined by two parallel definitions.

Notes

1 in obtaining the data for constructing the calibration graphs the capsule is prepared as follows: using a pipette into a capsule (A. 5.2) put 100 ml of water and dried at 90 °C for 2 hours.

2 the Amount of flux depends on the individual characteristics of the instrument and the type of analyzed material. The quantity of flux should provide complete combustion of the sample.

3. the Value of the reference experiment and the difference between the values of two parallel measurements control experiments should not exceed 0.01 mg on the carbon content. If these values are more, you need to install and eliminate the cause of contamination.

A. 7.4 analysis

Tin capsule (A. 5.2) is placed in a ceramic crucible (A. 5.3), slightly pressing it down, put it in a suspension (A. 7.2) (see note to A. 7.2) analyzed samples and the corresponding amount of flux (A. 4.8). The crucible with the contents put on a special stand for crucibles, lead the device in the mode of combustion and closed combustion chamber. According to the instruction manual of the device include oven. At the end of combustion and measuring the crucible is removed and record the results of the analysis.

A. 7.5 Construction of calibration curve

A. 7.5.1 Samples with a mass fraction of carbon from 0.003% to 0.01%.

A. 7.5.1.1 Preparation of the calibration solutions

Five volumetric flasks with a capacity of 250 ml is placed different amounts of a standard solution of sucrose (A. 4.9) or sodium carbonate (table A. 1), adjusted to the mark with water and mix. Using a micropipette injected with 100 ml each of the obtained solutions into tin capsules, dried at 90 °C for 2 h and cooled to room temperature in a desiccator.

Table A. 1

Volume standard solution, ml
Weight of carbon in dilute solution,
mg/ml
The mass of carbon stored in the capsule, mg
Mass fraction of carbon in the analyzed sample, %
0*
0
0
0
1,0 0,10 0,010 0,001
2,0
0,20 0,020 0,002
5,0
0,50 0,050 0,005
10,0
Of 1.00 0,100 0,010
* Zero solution (blank experiment).

A. 7.5.1.2 Measurement

The tin capsule containing sucrose or sodium carbonate, placed in a ceramic crucible (A. 5.3) and slightly press it to the bottom of the crucible, add 1,000 g of iron of high purity (A. 4.3) and the required amount of flux (note 2 to A. 7.3).

The crucible with the contents is carried out through the entire course of the analysis, as indicated in A. 7.4.

A. 7.5.1.3 Construction of calibration curve

One of the values defined for each calibration solution, subtract the values obtained for the reference experiment. The calibration curve built according to the found thus true readings of the scale and their corresponding carbon content in milligrams in each calibration solution series.

A. 7.5.2 Samples with a mass fraction of carbon from 0.01% to 0.1%

A. 7.5.2.1 Preparation of calibration solutions series

Five volumetric flasks with a capacity of 50 ml was placed different amounts of a standard solution of sucrose (A. 4.9) or sodium carbonate (table A. 2), adjusted to the mark with water and mix. Using a micropipette to introduce 100 ál of the resulting solutions into tin capsules, dried at 90 °C for 2 h and cooled to room temperature in a desiccator.

Table A. 2

Volume standard solution, ml
Weight of carbon in dilute solution,
mg/ml
The mass of carbon stored in the capsule, mg
Mass fraction of carbon in the analyzed sample, %
0*
0
0
0
2,0 1,0 0,10 0,010
4,0
2,0 0,20 0,020
10,0
5,0 0,50 0,050
20,0
10,0 Of 1.00 0,100
* Zero solution (blank experiment).

A. 7.5.2.2 Measurement

Perform, as specified in A. 7.5.1.2.

A. 7.5.2.3 Construction of calibration curve

Perform, as specified in A. 7.5.1.3.

A. 7.5.3 Samples with a mass fraction of carbon of from 0.1% to 1.0%

A. 7.5.3.1 Preparation of calibration solutions series

Specified in table A. 3 sample barium carbonate (A. 4.6) or sodium carbonate (A. 4.7) weigh to the nearest 0.1 mg and placed in a capsule (A. 5.2).

Table A. 3

The mass of a standard substance mg
The mass of carbon contained in a tin capsule, mg Mass fraction of carbon in the sample %
Barium carbonate
Sodium carbonate
0*
0
0
0
16,4
8,8 1,0 0,10
32,9
17,7 2,0 0,20
82,1 44.1 kHz 5,0 0,50
164,3 88,2 10,0 Of 1.00
* Zero solution (blank experiment).

A. 7.5.3.2 Measurement

The tin capsule containing barium carbonate or sodium carbonate, placed in a ceramic crucible, lightly pinning her to the bottom of the crucible, add 1,000 g of iron of high purity (A. 4.3) and the required amount of flux (note 2 to A. 7.3).

The crucible with the contents is carried out through the entire course of the analysis, as indicated in A. 7.4.

A. 7.5.3.3 Construction of calibration curve

Perform, as specified in A. 7.5.1.3.

A. 7.5.4 Samples with a mass fraction of carbon is from 1.0% to 4.5%

A. 7.5.4.1 Preparation of the calibration series

Specified in table A. 4 sample barium carbonate (A. 4.6) or sodium carbonate (A. 4.7) weigh to the nearest 0.1 mg and placed in a capsule.

Note — If a charge of sodium carbonate or barium carbonate is not placed in a tin capsule, it can be put directly on the bottom of the ceramic crucible.

Table A. 4

The mass of a standard substance mg
The mass of carbon contained in a tin capsule, mg Mass fraction of carbon in the sample %
Barium carbonate
Sodium carbonate
0*
0
0
0
82,1
44.1 kHz 5,0 Of 1.00
164,3
88,2 10,0 Of 2.00
246,4
132,3 15,0 Of 3.00
369,7
198,6 22,5 4,5
* Zero solution (blank experiment).

A. 7.5.4.2 Measurement

The tin capsule containing barium carbonate or sodium carbonate, placed in a ceramic crucible (A. 5.3) and slightly press down it to the bottom of the crucible, add 0,5000 g iron of high purity (A. 4.3) and the required amount of flux (note 2 to A. 7.3).

The crucible with the contents is carried out through the entire course of the analysis, as indicated in A. 7.4.

A. 7.5.4.3 Construction of calibration curve

Perform, as specified in A. 7.5.1.3.

A. 8 Handling of results

A. 8.1 Method of calculation

According to the obtained for the analyzed samples the readings of the instrument scale is determined by the calibration chart corresponding values of the carbon content in milligrams.

Mass fraction of carbon ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, % calculated according to the formula

ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, (A. 1)


where ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углеродаis the mass of carbon contained in the analyzed sample, mg;


ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода — the mass of carbon in a control experiment, mg;

ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода — mass of test sample, g.

A. 8.2 the accuracy of the method

The quality of the measurement in this method is characterized by the following metrological characteristics: repeatability ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, intralaboratory reproducibility ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углеродаand interlaboratory reproducibility ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода.

Between the mass fraction of carbon and values ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углеродаand ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углеродаin table A. 5, there is a logarithmic dependence.

Table A. 5

Mass fraction of carbon, %

Convergence ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, %

Internal control of reproducibility ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, %

Inter-laboratory control of reproducibility ГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода, %

0,003
0,00053
0,00119
0,00077
0,005
0,00069
0,00160
0,00102
0,01
0,00099
0,00240
0,00150
0,02
0,00142
0,00359
0,00220
0,05
0,00229
0,00612
0,00365
0,1
0,00329
0,00917
0,00536
0,2
0,00472
0,0137
0,00785
0,5
0,00762
0,0234
0,0130
1,0
0,0110
0,0351
0,0191
2,0
0,0157
0,0526
0,0280
4,5
0,0240
0,0844
0,0438

A. 9 test report

The test report must contain the following information:

— all the information about the laboratory and date of analysis;

— the method used with reference to this standard;

the results;

— any unusual features noted during the analysis;

— any operation not specified in this standard, or any activities which could affect the results of the analysis.

ANNEX B (reference). Technical features of induction furnaces and infrared analyzers manufactured for determination of carbon

APPENDIX B
(reference)

B. 1 oxygen Source (cylinder or coloradobased) shall be fitted with a pressure reducing valve and pressure gauge to control the pressure of oxygen fed into the furnace, wherein the pressure regulator shall be designed to 28 kg/mГОСТ 12344-2003 Стали легированные и высоколегированные. Методы определения углерода.

B. 2 purification unit for oxygen consists of the absorption tube for carbon dioxide absorption, is filled with asbestos impregnated with sodium hydroxide, and the drainage tube with the rate of magnesium.

B. 3 gas flow Meter (rheometer), designed for measurement in the range of 0−4 l/min.

B. 4 high-Frequency induction furnace

B. 4.1 incinerator consists of an induction coil and high frequency oscillator. The furnace chamber is a silica tube (outer diameter 30−40 mm, inner diameter 26−36 mm, tube length of 200−220 mm), which is inserted inside the induction coil. On the ends of the tube are metal plates reinforced with metal rings. The plates have inlet and outlet openings for gas.

B. 4.2 high Frequency generator with* 1.5−2.5 kW may have a different frequency depending on the specific manufacturer: 2−6 MHz, 15 MHz or 20 MHz. Energy from the generator is supplied to an induction coil, which is placed in a silica tube, and cooled by air.
___________________
* The text matches the original. — Note the manufacturer’s database.

B. 4.3 Crucible with sample, submerged arc and flux are placed on a stand, positioned so that when lifting the metal in the crucible was directly inside an induction coil that provides effective communication when power is applied.

B. 4.4 the diameter of the induction coil the number of turns, the geometric dimensions of the furnace chamber and a power generator is determined by the manufacturer.

B. 4.5, the combustion Temperature depends on the factors specified in B. 4.4, and the properties of the metal in the crucible, the shape and mass of the analyzed sample.

B. 5 the system is equipped with a dust collector, designed for cleaning current of oxygen leaving the furnace from dust and metal oxides.

B. 6 Desulfonema tube consists of a heated oxidation tube filled with platinum or platinized silicon dioxide, and filter to absorb the sulfur trioxide containing cellulose fiber.

B. 7 Infrared analyzer

B. 7.1 For most devices of this type it is characteristic that the gaseous products of combustion are transferred to the analyzer system continuous flow oxygen. The gas flow passes through a cell where the photocell detects the radiation absorbed by the dioxide or a mixture of the dioxide and carbon monoxide in the infrared region of the spectrum; the radiation is measured and summed over a given period of time. The signal converted into the percentage of carbon and output to the scale of the instrument.

B. 7.2 In some analyzers, the products of combustion are collected in an atmosphere of oxygen at a controlled pressure in a given volume, and this mixture is analyzed for the content of the monoxide and/or carbon dioxide.

B. 7.3, the Analyzer usually supply electronic devices for setting the instrument scale to zero, compensation for the idle experience, set the slope of the calibration curve and correction in case of its nonlinear character. In addition, the analyzer is usually a device for introducing the mass of sample standard sample and a test sample for automatic correction of the read result. The devices can also be equipped with automatic scales for weighing of crucibles, samples and test portions of the subjects transfer values of their mass into the calculator.



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M.: STANDARTINFORM, 2008