ASTM E1941-98

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Designation: E 1941 – 98
Standard Test Method for
Determination of Carbon in Refractory and Reactive Metals
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and Their Alloys
This standard is issued under the fixed designation E 1941; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope furnace. The carbon in the specimen is oxidized to carbon
dioxide or carbon monoxide, or both, and is eventually carried
1.1 This test method applies to the determination of carbon
to the analyzer/detector. The amount of carbon present is
in refractory and reactive metals and their alloys in concentra-
electronically processed and is displayed by the analyzer
tions from 0.004 to 0.100 % (see Note 1).
readout.
NOTE 1—Actual instrument range might vary from manufacturer to
3.2 This test method is written for use with commercially
manufacturer and according to sample size.
available analyzers equipped to carry out the above operations
1.2 This standard does not purport to address all of the
and calibrated using commercially available standards of
safety concerns, if any, associated with its use. It is the
known carbon content.
responsibility of the user of this standard to establish appro-
4. Significance and Use
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. Specific precau-
4.1 This test method is intended to test for compliance with
tionary statements are given in Section 8.
compositional specifications. It is assumed that all who use this
method will be trained analysts capable of performing common
2. Referenced Documents
laboratory procedures skillfully and safely. It is expected that
2.1 ASTM Standards:
the work will be performed in a properly equipped laboratory.
E 29 Practice for Using Significant Digits in Test Data to
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5. Interferences
Determine Conformance with Specifications.
E 50 Practices for Apparatus, Reagents, and Safety Precau-
5.1 The elements ordinarily present in these alloys do not
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tions for Chemical Analysis of Metals
interfere. Halides that are present in some sponge type samples
E 55 Practice for Sampling Wrought Nonferrous Metals and
will cause low carbon recovery.
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Alloys for the Determination of Chemical Composition
6. Apparatus
E 1601 Practice for conducting an Interlaboratory Study to
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Evaluate the Performance of an Analytical Method 6.1 Combustion Furnace and Measurement Apparatus, au-
2
E 456 Terminology for Statistical Methods
tomatic carbon determinator, consisting of an induction fur-
E 1019 Test Methods for Determination of Carbon, Sulfur, nace; a dust/debris removal trap; an analytical gas stream
Nitrogen, Oxygen, and Hydrogen in Steel and in Iron,
purification system; an infrared detection system; and an
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Nickel, and Cobalt Alloys. automatic readout (see Note 2).
NOTE 2—Several models of commercial carbon determinators are
3. Summary of Test Method
available and presently in use in industry. Each has its own unique design
3.1 The metal specimen, contained in a single-use ceramic
characteristics and operational requirements. Consult the instrument
crucible, is ignited in an oxygen atmosphere in an induction
manufacturer’s instruction manuals for operational details.
6.2 Oxygen Tank and Regulator.
1 6.3 Ceramic Crucibles and Lids, that meet or exceed the
This test method is under the jurisdiction of ASTM Committee E-1 on
Analytical Chemistry for Metals, Ores, and Related Materials and is the direct instrument manufacturer’s specifications. Use lids with holes
responsibility of Subcommittee E01.06 on Titanium, Zirconium, Tungsten, Molyb-
in them.
denum, Tantalum, Niobium, Hafnium, and Rhenium.
6.4 Crucible Tongs, capable of handling recommended cru-
Current edition approved Feb. 10, 1998. Published August 1998.
2
cibles.
Annual Book of ASTM Standards, Vol 14.02.
3
Annual Book of ASTM Standards, Vol 03.05.
6.5 Balance, capable of weighing to the nearest milligram.
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Annual Book of ASTM Standards, Vol 03.06.
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E1941–98
6.6 Muffle Furnace, capable of reaching and sustaining a calibration RM’s will consist of a commercial RM’s of known
temperature of at least 700°C. carbon content (standard value should slightly exceed that of
the unknown), one scoop (approximately 1 g) of iron chip
7. Reagents
accelerator and one scoop (approximately 1.5 g) of copper
7.1 Acetone (A.R., or other suitable, degreasing reagents).
accelerator in a prepared crucible, plus a prepared crucible lid.
7.2 Copper Accelerator, (
...