ASTM C1025-91(2000)

Standard Test Method for Modulus of Rupture in Bending of Electrode Graphite

SCOPE
1.1 This test method covers determination of the modulus of rupture in bending of specimens cut from graphite electrodes using a simple square cross section beam in four-point loading at room temperature.
1.2 The values stated in SI units are to be regarded as standard.  
1.3 This standard does not purport to address all of the safety problems, 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: 09-Apr-2000
• ICS: 71.100.99 - Other products of the chemical industry
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.F0 - Manufactured Carbon and Graphite Products

Relations

• Replaced By: ASTM C1025-91(2005) - Standard Test Method for Modulus of Rupture in Bending of Electrode Graphite
• Effective Date: 01-Jun-2005
• Referred By: ASTM C783-85(2020) - Standard Practice for Core Sampling of Graphite Electrodes
• Effective Date: 10-Apr-2000
• Referred By: ASTM D6354-23 - Standard Guide for Sampling Plan and Core Sampling of Carbon Cathode Blocks Used in Aluminum Production
• Effective Date: 10-Apr-2000

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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An American National Standard
Designation:C 1025–91(Reapproved 2000)
Standard Test Method for
Modulus of Rupture in Bending of Electrode Graphite
This standard is issued under the fixed designation C 1025; 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 4. Significance and Use
1.1 Thistestmethodcoversdeterminationofthemodulusof 4.1 This test method provides a means for determining the
rupture in bending of specimens cut from graphite electrodes modulus of rupture of a square cross section graphite specimen
using a simple square cross section beam in four-point loading machinedfromtheelectrodecoresampleobtainedaccordingto
at room temperature. Practice C 783, with a minimum core diameter of 57 mm (2.25
1.2 The values stated in SI units are to be regarded as the in.) This test method is recommended for quality control or
standard. The values given in parentheses are for information quality assurance purposes, but should not be relied upon to
only. compare materials of radically different particle sizes or
1.3 This standard does not purport to address all of the orientational characteristics. For these reasons as well as those
safety concerns, if any, associated with its use. It is the discussed in 4.2 an absolute value of flexural strength may not
responsibility of the user of this standard to establish appro- be obtained.
priate safety and health practices and determine the applica- 4.2 Specimen Size— The maximum particle size and maxi-
bility of regulatory limitations prior to use. mum pore size vary greatly for manufactured graphite elec-
trodes, generally increasing with electrode diameter.The test is
2. Referenced Documents
on a rather short stubby beam, therefore the shear stress is not
2.1 ASTM Standards: insignificant compared to the flexural stress, and the test results
C 651 Test Method for Flexural Strength of Manufactured
may not agree when a different ratio or specimen size is used.
Carbon and GraphiteArticles Using Four-Point Loading at
5. Apparatus
Room Temperature
C 709 Terminology Relating to Manufactured Carbon and 5.1 The testing machine shall conform to the requirements
Graphite of Sections 14 and 17 of Practices E 4.
C 783 Practice for Core Sampling of Graphite Electrodes 5.2 The four-point loading fixture shall consist of bearing
E 4 Practices for Force Verification of Testing Machines blocks which ensure that forces applied to the beam are normal
E 691 Practice for Conducting an Interlaboratory Study to only and without eccentricity. (See Test Method C 651.) The
Determine the Precision of a Test Method directions of loads and reactions may be maintained parallel by
judicious use of linkages, rocker bearings, and flexure plates.
3. Terminology
Eccentricity of loading can be avoided by the use of spherical
3.1 Definitions: For definitions of terms relating to manu- bearings. Provision must be made in fixture design for relief of
factured carbon and graphite, see Terminology C 709.
torsional loading to less than 5 % of the nominal specimen
3.2 Definitions of Terms Specific to This Standard: strength. Refer to Fig. 1 for a suggested four-point fixture.
3.2.1 modulus of rupture in bending— the value of maxi-
5.3 The bearing block diameter shall be between ⁄10 and
mum stress in the extreme fiber of a specified beam loaded to ⁄20 of the specimen support span, 12 mm (0.50 in.) to 6 mm
failure in bending computed from the calculations in Section 9.
(0.25 in.). A hardened steel bearing block or its equivalent is
necessary to prevent distortion of the loading member.
6. Test Specimen
This test method is under the jurisdiction of ASTM Committee D02 on
6.1 Sampling—A core sample (minimum of 57 mm (2.25
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
in.) diameter and 165 mm (6.50 in.) long) shall be obtained
D02.F on Manufactured Carbon and Graphite Products .
Current edition approved Feb. 22, 1991. Published June 1991. Originally
from the electrode in accordance with Practice C 783.
published as C 1025 – 84. Last previous edition C 1025 – 84.
6.2 Preparation— A test specimen shall be prepared from
Annual Book of ASTM Standards, Vol 05.05.
3 the core to yield a parallelepiped of square cross section. The
Annual Book of ASTM Standards, Vol 03.01.
Annual Book of ASTM Standards, Vol 14.02. faces shall be parallel and flat within 0.002 mm/mm (0.002
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 1025
FIG. 1 Beam with Four-Point Loading (Not to Scale)
in./in.) of length. Specimen edges shall be free from visible 9. Calculation
flaws and chips. All surfaces shall be smooth with a surface
9.1 If the fracture occurs within the load span, calculate the
texture equivalent to that obtained from a precision band saw
modulus of rupture, the maximum bending moment, the
or better.
distance from the neutral axis to the location where the fiber
6.3 Thesquarecrosssectionspecimenshallbe38by38mm
failed, and the moment of inertia of the original cross section
(1.50 by 1.50 in.) and at least 153 mm (6.0 in.) long.
as follows:
6.4 Measurements—All dimensions shall be measured to at
9.1.1 Modulus of rupture:
least 0.03 mm (0.001 in.).
MOR 5 Mc/I
6.5 Drying—Each specimen must be dried in an oven at
MOR 5 ~PL/bt !~1000!
greater than 110°C for 2 h. The specimen must then be cooled
to room temperature in a desiccator and held there prior to
9.1.2 Maximum bending moment:
testing.
M 5 ~P/2!~L/3!
7. Procedure 9.1.3 Distance from the neutral axis to the location where
the fiber failed:
7.1 Center the specimen in the test fixture. Mak
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