ASTM E2050-17

Standard Test Method for Determination of Total Carbon in Mold Powders by Combustion

SIGNIFICANCE AND USE
5.1 This test method for the determination of total carbon in mold powders is primarily intended to test such materials for compliance with compositional specifications. It is assumed that all who use this test method will be trained analysts capable of performing common laboratory procedures skillfully and safely. It is expected that the work will be performed in a properly equipped laboratory and that proper waste disposal procedures will be followed. Appropriate quality control practices must be followed such as those described in Guide E882.
SCOPE
1.1 This test method covers the determination of total carbon in mold powders in the concentration range from 1 % to 25 %.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This test method has been evaluated in accordance with Practice E1601 and Guide E1763. Unless otherwise noted in the precision and bias section, the lower limit in the scope of each method specifies the lowest analyte content that may be analyzed with acceptable error (defined as a nominal 5 % risk of obtaining a 50 % or larger relative difference in results on the same test sample in two laboratories).  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2017
• ICS: 83.080.01 - Plastics in general
• Technical Committee: E01 - Analytical Chemistry for Metals, Ores, and Related Materials
• Drafting Committee: E01.02 - Ores, Concentrates, and Related Metallurgical Materials

Relations

• Replaces: ASTM E2050-12a - Standard Test Method for Determination of Total Carbon in Mold Powders by Combustion
• Effective Date: 01-Apr-2017
• Refers: ASTM E135-20 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Jan-2020
• Refers: ASTM E1601-19 - Standard Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method
• Effective Date: 01-Nov-2019
• Refers: ASTM E135-19 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-May-2019
• Refers: ASTM E50-17 - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 01-Sep-2017
• Refers: ASTM E882-10(2016)e1 - Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
• Effective Date: 01-Dec-2016
• Refers: ASTM E882-10(2016) - Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
• Effective Date: 01-Dec-2016
• Refers: ASTM E50-11(2016) - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 01-Aug-2016
• Refers: ASTM E135-16 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-May-2016
• Refers: ASTM E135-15a - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Jul-2015
• Refers: ASTM E135-15 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-May-2015
• Refers: ASTM E135-14b - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-Aug-2014
• Refers: ASTM E135-14a - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Apr-2014
• Refers: ASTM E135-14 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-Feb-2014
• Refers: ASTM E135-13a - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Dec-2013

Overview

ASTM E2050-17: Standard Test Method for Determination of Total Carbon in Mold Powders by Combustion provides a standardized procedure for accurately measuring the total carbon content in mold powders within a concentration range of 1% to 25%. This method, developed by ASTM International, is crucial for ensuring compliance with compositional specifications in materials used primarily in the continuous casting of steel. The procedure is intended for qualified laboratory analysts using appropriate safety and quality control measures.

Key Topics

• Purpose and Scope

  • Focuses on quantifying total carbon in metallurgical mold powders used in steelmaking.
  • Applicable carbon concentration range: 1% to 25% (by mass fraction).
  • Uses only SI units for consistency and global acceptability.

• Method Summary

  • Mold powder samples are combusted in an oxygen stream, converting carbon to carbon dioxide (CO₂) and carbon monoxide (CO).
  • The mixture is further processed so that all carbon monoxide is converted to carbon dioxide.
  • Carbon dioxide is measured using infrared absorption spectrometry for precise quantification.
  • Halogen interference (mainly from fluorides or chlorides in mold powders) is eliminated using a dedicated halogen trap in the apparatus.

• Significance

  • Ensures mold powders meet precise compositional requirements essential for steel casting operations.
  • Supports quality control, specification verification, and regulatory compliance within metallurgical industries.

• Quality Control and Safety

  • Requires strict adherence to laboratory safety and sample handling protocols.
  • Quality assurance practices as outlined in ASTM Guide E882 are recommended.
  • Regular instrument calibration and method verification are integral to reliable results.

Applications

• Steel Manufacturing

  • Critical for monitoring and controlling the carbon content in mold powders used in the continuous casting process, where precise material composition affects lubrication, thermal insulation, and overall cast product quality.

• Materials Testing Laboratories

  • Suitable for laboratories required to verify mold powder batches against customer or regulatory specifications.
  • Enables reliable interlaboratory comparison studies, as the method is evaluated according to ASTM Practice E1601.

• Research and Development

  • Supports R&D teams in optimizing mold powder formulations to improve metallurgical performance or develop new products for steelmaking.

Related Standards

• ASTM E29: Guidelines on the use of significant digits in test data for conformity assessment.
• ASTM E50: Practices for handling apparatus, reagents, and safety considerations in the chemical analysis of metals, ores, and related materials.
• ASTM E135: Terminology relevant to analytical chemistry of metals, ores, and related materials.
• ASTM E882: Guide for accountability and quality control in chemical analysis laboratories.
• ASTM E1019: Test methods for determining carbon, sulfur, nitrogen, and oxygen in steel, iron, nickel, and cobalt alloys, including combustion techniques relevant to E2050.
• ASTM E1601: Practice for assessing analytical method performance through interlaboratory studies.
• ASTM E1763: Guide for interpretation of results from interlaboratory testing of chemical analysis methods.

Practical Value

Implementing ASTM E2050-17 ensures accurate, reproducible total carbon analysis in mold powders, supporting product quality, regulatory compliance, and process improvement in steelmaking and metallurgical laboratories. By following this international standard, organizations can confidently verify mold powder compositions, minimize process variability, and enhance product reliability on a global scale.

Keywords: ASTM E2050-17, total carbon determination, mold powders, combustion analysis, infrared absorption, metallurgical testing, steel casting, quality control, laboratory analysis, compositional specification.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E2050 − 17
Standard Test Method for
Determination of Total Carbon in Mold Powders by
Combustion
This standard is issued under the fixed designation E2050; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope erations for Chemical Analysis of Metals, Ores, and
Related Materials
1.1 This test method covers the determination of total
E135 Terminology Relating to Analytical Chemistry for
carboninmoldpowdersintheconcentrationrangefrom1 %to
Metals, Ores, and Related Materials
25 %.
E882 Guide for Accountability and Quality Control in the
1.2 The values stated in SI units are to be regarded as
Chemical Analysis Laboratory
standard. No other units of measurement are included in this
E1019 Test Methods for Determination of Carbon, Sulfur,
standard.
Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt
1.3 This test method has been evaluated in accordance with Alloys by Various Combustion and Fusion Techniques
E1601 Practice for Conducting an Interlaboratory Study to
Practice E1601 and Guide E1763. Unless otherwise noted in
the precision and bias section, the lower limit in the scope of Evaluate the Performance of an Analytical Method
E1763 Guide for Interpretation and Use of Results from
each method specifies the lowest analyte content that may be
analyzed with acceptable error (defined as a nominal 5 % risk Interlaboratory Testing of Chemical Analysis Methods
(Withdrawn 2015)
of obtaining a 50 % or larger relative difference in results on
the same test sample in two laboratories).
3. Terminology
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.1 Definitions—For definitions of terms used in this test
responsibility of the user of this standard to establish appro-
method, refer to Terminology E135.
priate safety and health practices and determine the applica-
3.2 Definitions of Terms Specific to This Standard:
bility of regulatory limitations prior to use.
3.2.1 mold powder, n— in the continuous-casting of steel, a
1.5 This international standard was developed in accor-
metallurgical flux used to provide lubrication of the mold,
dance with internationally recognized principles on standard-
enhance heat transfer at the strand-mold interface, and provide
ization established in the Decision on Principles for the
thermal insulation of the liquid metal surface to prevent
Development of International Standards, Guides and Recom-
unwanted solidification.
mendations issued by the World Trade Organization Technical
3.2.1.1 Discussion—Key chemical components of these
Barriers to Trade (TBT) Committee.
powders are fluorides, the oxides of silicon and calcium, and
2. Referenced Documents
carbon.
2.1 ASTM Standards:
4. Summary of Test Method
E29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications
4.1 Carbon in the test sample is converted in a furnace to a
E50 Practices for Apparatus, Reagents, and Safety Consid-
mixture of carbon dioxide (CO ) and carbon monoxide (CO)
bycombustioninastreamofoxygen.FullconversionofCOto
CO occurs by the passage of sample gases through a catalytic
This test method is under the jurisdiction of ASTM Committee E01 on
heater assembly. The amount of CO is measured by infrared
Analytical Chemistry for Metals, Ores, and Related Materials and is the direct
responsibility of Subcommittee E01.02 on Ores, Concentrates, and Related Metal-
absorption. Any interference from halogens in the sample is
lurgical Materials.
eliminated by placement of a halogen trap between the furnace
Current edition approved April 1, 2017. Published June 2017. Originally
and the analyzer.
approved in 1999. Last previous edition approved in 2012 as E2050–12a. DOI:
10.1520/E2050-17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2050 − 17
TABLE 1 Statistical Information, Carbon Combustion/Infrared Method
Test Material Number of Carbon Found, % Minimum SD (S , Reproducibility SD, Reproducibility Index R
M rel%
Laboratories E1601) (S , E1601) (R, E1601)
g
B 7 1.2046 0.00601 0.02960 0.08288 6.88
A 7 3.1219 0.01269 0.04843 0.13559 4.34
C 7 6.5514 0.04774 0.09215 0.25803 3.94
D 7 10.5121 0.05788 0.10579 0.29620 2.82
E 7 15.1121 0.04964 0.14730 0.41244 2.73
F 7 19.7121 0.11949 0.25294 0.70824 3.59
G 7 29.4250 0.38830 0.60179 1.6850 5.73
5. Significance and Use 9.2 Oxygen, 99.5 % purity recommended. Other grades of
oxygen may be used if low and consistent blank readings are
5.1 This test method for the determination of total carbon in
obtained.
mold powders is primarily intended to test such materials for
compliance with compositional specifications. It is assumed 9.3 Tungsten/Tin or Copper Accelerator, high purity.
that all who use this test method will be trained analysts
10. Hazards
capable of performing common laboratory procedures skill-
fully and safely. It is expected that the work will be performed 10.1 For precautions to be observed in the use of reagents
in a properly equipped laboratory and that proper waste and apparatus in this method, refer to Practices E50 and Test
disposal procedures will be followed. Appropriate quality Methods E1019.
control practices must be followed such as those described in
10.2 Use care when handling hot crucibles and when
Guide E882.
operating furnaces to avoid personal injury by either burn or
electrical shock.
6. Rounding Calculated Values
11. Sampling and Sample Preparation
6.1 Calculated values shall be rounded in accordance with
Practice E29.
11.1 Materials Safety—Samples must be prepared, stored,
and disposed of in accordance with the materials and safety
7. Interferences
guidelines in Practices E50.
7.1 Halogens,normallypresentinmoldpowdersasfluoride,
11.2 Prepared Sample—Pulverize or grind the laboratory
will interfere with this test method. A halogen trap, as
sample until 100 % passes a No. 100 (150-µm) sieve. Store in
described in 8.4, must be installed in the measure line between
a suitable glass or plastic container.
the furnace and analyzer to prevent this interference.
12. Preparation of Apparatus
8. Apparatus
12.1 Test the furnace and analyzer to ensure the absence of
leaks. Prepare the analyzer for operation as directed in the
8.1 Combustion-Infrared Absorption Carbon Analyzer,
manufacturer’s instructions.
equipped with a combustion chamber, oxygen carrier stream,
halogentrap,catalyticheaterassembly,andinfraredabsorption
13. Calibration
detector, suitable for the analysis of carbon from 1 to 25 % in
13.1 Calibration Reference Materials—Tungsten carbide
mold powders. Instruments, such as those in Test Methods
certified for total carbon in the vicinity of 6.1 % C and silicon
E1019,whichcanbeshowntogiveequivalentresultsmayalso
carbide certified for total carbon in the vicinity of 29.4 % C.
be used for this test method.
NOTE 1—As originally approved, this standard relied on National
8.2 Crucibles—Use ceramic crucibles that meet or exceed
Institute of Standards and Technology SRM 276b Tungsten Carbide and
the specifications of those recommended by the manufacturer
SRM 112b Silicon Carbide as cali
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E2050 − 12a E2050 − 17
Standard Test Method for
Determination of Total Carbon in Mold Powders by
Combustion
This standard is issued under the fixed designation E2050; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of total carbon in mold powders in the concentration range from 1 % to 25 %.
NOTE 1—As used in this test method, “percentage” or “%” refers to a mass fraction of the form (wt / wt %) (g/100g).
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This test method has been evaluated in accordance with Practice E1601 and Guide E1763. Unless otherwise noted in the
precision and bias section, the lower limit in the scope of each method specifies the lowest analyte content that may be analyzed
with acceptable error (defined as a nominal 5 % risk of obtaining a 50 % or larger relative difference in results on the same test
sample in two laboratories).
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E50 Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
E882 Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
E1019 Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by
Various Combustion and Fusion Techniques
E1601 Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method
E1763 Guide for Interpretation and Use of Results from Interlaboratory Testing of Chemical Analysis Methods (Withdrawn
2015)
3. Terminology
3.1 Definitions—For definitions of terms used in this test method, refer to Terminology E135.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 mold powder, n— in the continuous-casting of steel, a metallurgical flux used to provide lubrication of the mold, enhance
heat transfer at the strand-mold interface, and provide thermal insulation of the liquid metal surface to prevent unwanted
solidification.
This test method is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and is the direct responsibility of
Subcommittee E01.02 on Ores, Concentrates, and Related Metallurgical Materials.
Current edition approved June 1, 2012April 1, 2017. Published July 2012June 2017. Originally approved in 1999. Last previous edition approved in 2012 as
E2050–12.–12a. DOI: 10.1520/E2050-12A.10.1520/E2050-17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
3.2.1.1 Discussion—
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2050 − 17
Key chemical components of these powders are fluorides, the oxides of silicon and calcium, and carbon.
4. Summary of Test Method
4.1 Carbon in the test sample is converted in a furnace to a mixture of carbon dioxide (CO ) and carbon monoxide (CO) by
combustion in a stream of oxygen. Full conversion of carbon monoxide CO to carbonCO dioxide occurs by the passage of sample
gases through a catalytic heater assembly. The amount of carbonCO dioxide is measured by infrared absorption. Any interference
from halogens in the sample is eliminated by placement of a halogen trap between the furnace and the analyzer.
5. Significance and Use
5.1 This test method for the determination of total carbon in mold powders is primarily intended to test such materials for
compliance with compositional specifications. It is assumed that all who use this test method will be trained analysts capable of
performing common laboratory procedures skillfully and safely. It is expected that the work will be performed in a properly
equipped laboratory and that proper waste disposal procedures will be followed. Appropriate quality control practices must be
followed such as those described in Guide E882.
6. Rounding Calculated Values
6.1 Calculated values shall be rounded in accordance with Practice E29.
7. Interferences
7.1 Halogens, normally present in mold powders as fluoride, will interfere with this test method. A halogen trap, as described
in 8.4, must be installed in the measure line between the furnace and analyzer to prevent this interference.
8. Apparatus
8.1 Combustion-Infrared Absorption Carbon Analyzer, equipped with a combustion chamber, oxygen carrier stream, halogen
trap, catalytic heater assembly, and infrared absorption detector, suitable for the analysis of carbon from 1 %1 to 25 % in mold
powders. Instruments, such as those in Test Methods E1019, which can be shown to give equivalent results may also be used for
this test method.
8.2 Crucibles—Use ceramic crucibles that meet or exceed the specifications of those recommended by the manufacturer of the
instrument.
8.3 Crucible Tongs, capable of handling recommended crucibles.
8.4 Halogen (Fluorine/Chlorine) Trap, ,available from the instrument manufacturer as a kit, consisting of the parts and
necessary reagents for assembly. Follow the manufacturer’s instructions for the assembly, installation, use, and proper maintenance
of the trap.
8.5 Metal Scoop, for dispensing metal chips.chips (accelerators).
9. Reagents and Materials
9.1 Iron Chip, high purity (−6 mesh to +20 mesh).purity.
9.2 Oxygen, 99.5 % purity recommended. Other grades of oxygen may be used if low and consistent blank readings are
obtained.
9.3 Tungsten/Tin or Copper Accelerator, high purity.
NOTE 2—Copper chip accelerator (−20 mesh to +30 mesh) may be used in place of Tungsten/Tin.
10. Hazards
10.1 For precautions to be observed in the use of reagents and apparatus in this method, refer to Practices E50 and Test Methods
E1019.
10.2 Use care when handling hot crucibles and when operating furnaces to avoid personal injury by either burn or electrical
shock.
11. Sampling and Sample Preparation
11.1 Materials Safety—Samples must be prepared, stored, and disposed of in accordance with the materials and safety
guidelines in Practices E50.
11.2 Prepared Sample—Pulverize or grind the laboratory sample until 100 % passes a No. 100 (150-μm) sieve. Store in a
suitable glass or plastic container.
E2050 − 17
TABLE 1 Statistical Information, Carbon Combustion/Infrared Method
Test Material Number of Carbon Found, % Minimum SD Reproducibility SD, Reproducibility Index R
rel%
Laboratories (S ,E1601) (S ,E1601) (R,E1601)
M g
B 7 1.2046 0.00601 0.02960 0.08288 6.88
A 7 3.1219 0.01269 0.04843 0.13559 4.34
C 7 6.5514 0.04774 0.09215 0.25803 3.94
D 7 10.5121 0.05788 0.10579 0.29620 2.82
E 7 15.1121 0.04964 0.14730 0.41244 2.73
F 7 19.7121 0.11949 0.25294 0.70824 3.59
G 7 29.4250 0.38830 0.60179 1.6850 5.73
12. Preparation of Apparatus
12.1 Test the furnace and analyzer to ensure the absence of leaks. Prepare the analyzer for operation in accordance withas
directed in the manufacturer’s instructions.
13. Calibration
13.1 Calibration Reference Materials—Tungsten carbide (6.10 % total carbon), NIST SRM 276b, or equivalent; silicon carbide
(29.43 % total carbon), NIST SRM 112b, or equivalent (certified for total carbon in the vicinity of 6.1 % C and silicon carbide
certified for total carbon in the vicinity of 29.4 %No
...