ASTM D6745-06

Standard Test Method for Linear Thermal Expansion of Electrode Carbons

SIGNIFICANCE AND USE
Coefficients of linear thermal expansion are used for design and quality control purposes and to determine dimensional changes of parts and components (such as carbon anodes, cathodes, and so forth) when subjected to varying temperatures.
SCOPE
1.1 This test method covers the determination of the coefficient of linear thermal expansion (CTE) for carbon anodes and cathodes used in the aluminum industry, in baked form, by use of a vitreous silica dilatometer.
1.2 The applicable temperature range for this test method for research purposes is ambient to 1000°C. The recommended maximum use temperature for product evaluation is 500°C.
1.3 This test method and procedure is based on Test Method E 228, which is a generic all-encompassing method. Specifics dictated by the nature of electrode carbons and the purposes for which they are used are addressed by this procedure.
1.4 Electrode carbons in the baked form will only exhibit primarily reversible dimensional changes when heated.
1.5 The values stated in SI units are to be regarded as standard.
1.6 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.

General Information

• Status: Historical
• Publication Date: 31-Dec-2005
• ICS: 19.060 - Mechanical testing
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.05 - Properties of Fuels, Petroleum Coke and Carbon Material

Relations

• Replaces: ASTM D6745-01 - Standard Test Method for Linear Thermal Expansion of Electrode Carbons
• Effective Date: 01-Jan-2006
• Replaced By: ASTM D6745-06(2011) - Standard Test Method for Linear Thermal Expansion of Electrode Carbons
• Effective Date: 01-May-2011
• Referred By: ASTM D6353-23 - Standard Guide for Sampling Plan and Core Sampling for Prebaked Anodes Used in Aluminum Production
• Effective Date: 01-Jan-2006

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6745 – 06
Standard Test Method for
1
Linear Thermal Expansion of Electrode Carbons
This standard is issued under the fixed designation D6745; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope specimens lengths at reference temperature T and test tem-
0
perature T , respectively. Linear thermal expansion is often
1.1 This test method covers the determination of the coef- 1
expressed as a percentage or in parts per million (such as
ficient of linear thermal expansion (CTE) for carbon anodes
µm/m).
andcathodesusedinthealuminumindustry,inbakedform,by
3.1.2 mean coeffıcient of linear thermal expansion (CTE)—
use of a vitreous silica dilatometer.
The linear thermal expansion per change in temperature; the
1.2 The applicable temperature range for this test method
mean coefficient of linear thermal expansion is represented by:
forresearchpurposesisambientto1000°C.Therecommended
maximum use temperature for product evaluation is 500°C. DL/L 1 DL 1 L 2 L
0 1 0
a 5 5 · 5 (1)
T
1
DT L DT L T 2 T
1.3 ThistestmethodandprocedureisbasedonTestMethod
0 0 1 0
E228, which is a generic all-encompassing method. Specifics
3.1.2.1 Thishastobeaccompaniedbythevaluesofthetwo
dictatedbythenatureofelectrodecarbonsandthepurposesfor
temperatures to be meaningful; the reference temperature (T )
0
which they are used are addressed by this procedure.
is 20°C, and the notation may then only contain a single
1.4 Electrode carbons in the baked form will only exhibit
number, such as a¯ , meaning the mean coefficient of linear
200
primarily reversible dimensional changes when heated.
thermal expansion between 20 and 200°C.
1.5 The values stated in SI units are to be regarded as
3.2 Definitions of Terms Specific to This Standard:
standard.
3.2.1 reference specimen—a particularly identified or pedi-
1.6 This standard does not purport to address all of the
greed material sample, with well-characterized behavior and
safety concerns, if any, associated with its use. It is the
independently documented performance.
responsibility of the user of this standard to establish appro-
3.2.2 specimen—a representative piece of a larger body
priate safety and health practices and determine the applica-
(anode, cathode, and so forth) that is considered to be fairly
bility of regulatory limitations prior to use.
typical of a portion or of the entire piece.
3.2.3 vitreous silica dilatometer—a device used to deter-
2. Referenced Documents
mine linear thermal expansion, by measuring the difference in
2
2.1 ASTM Standards:
linear thermal expansion between a test specimen and the
E228 Test Method for Linear Thermal Expansion of Solid
vitreous silica parts of the dilatometer.
Materials With a Push-Rod Dilatometer
4. Summary of Test Method
3. Terminology
4.1 Arepresentativespecimenisplacedintoavitreoussilica
3.1 Definitions:
dilatometer and heated, while its linear expansion is continu-
3.1.1 linear thermal expansion—the change in length per
ously recorded.The change of the specimen length is recorded
unit length resulting from a temperature change. Linear ther-
as a function of temperature. The coefficient of linear thermal
malexpansionissymbolicallyrepresentedby DL/L ,where DL
0
expansion is then calculated from these recorded data.
isthelengthchangeofthespecimen(L −L ), L and L arethe
1 0 0 1
5. Significance and Use
1 5.1 Coefficients of linear thermal expansion are used for
This test method is under the jurisdiction of ASTM Committee D02 on
design and quality control purposes and to determine dimen-
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.
sional changes of parts and components (such as carbon
Current edition approved Jan. 1, 2006. Published February 2006. Originally
anodes, cathodes, and so forth) when subjected to varying
approved in 2001. Last previous edition approved in 2001 as D6745–01. DOI:
temperatures.
10.1520/D6745-06.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6. Apparatus
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
6.1 Dilatometer—Thedilatometerconsistsofthefollowing:
the ASTM website.
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D6745 – 06
6.1.1 Specimen Holder and Push-rod,bothmadeofvitreous 6.2.3 Computerized recording may be used with similar
silica. The des
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