iTeh StandardsiTeh Standards
EURUSD
Your shopping cart is empty.
ASTM

ASTM C748-98

(Test Method)

Standard Test Method for Rockwell Hardness of Graphite Materials

Standard Test Method for Rockwell Hardness of Graphite Materials

SCOPE
1.1 This test method covers Rockwell L scale hardness testing of fine-grained graphite materials with grain size less than 0.8 m ( 1/32 in.) and a hardness range between 0 and 120.  
1.2 Test Methods E18 shall be followed except where otherwise indicated.
1.3 The values stated in acceptable metric units are to be regarded as the standard. The values given in parentheses are provided for information purposes only.  
1.4 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-Mar-1998
ICS
71.060.10 - Chemical elements
Technical Committee
D02 - Petroleum Products, Liquid Fuels, and Lubricants
Drafting Committee
D02.F0 - Manufactured Carbon and Graphite Products
Current Stage
Ref Project

Relations

Replaced By
ASTM C748-98(2005) - Standard Test Method for Rockwell Hardness of Graphite Materials
Effective Date
01-May-2005
Referred By
ASTM D7775-21 - Standard Guide for Measurements on Small Graphite Specimens
Effective Date
10-Mar-1998

Buy Standard

ASTM C748-98 - Standard Test Method for Rockwell Hardness of Graphite MaterialsASTM C748-98 - Standard Test Method for Rockwell Hardness of Graphite Materials
PreviousNext
Standard
ASTM C748-98 - Standard Test Method for Rockwell Hardness of Graphite Materials
English language
3 pages
sale 15% off
Preview
sale 15% off
Preview

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
An American National Standard
Designation:C 748–98
Standard Test Method for
Rockwell Hardness of Graphite Materials
This standard is issued under the fixed designation C 748; 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 4.2 A Rockwell hardness number is directly related to the
indentation hardness of a material; the higher the Rockwell L
1.1 This test method covers Rockwell L scale hardness
scale reading, the harder the material. The test is useful in the
testing of graphite materials with grain size less than 0.8 m
evaluation and the manufacturing control of carbon and graph-
(0.032 in.) and a hardness range between 0 and 120.
ite materials.
1.2 Test Methods E18 shall be followed except where
otherwise indicated.
5. Apparatus
1.3 The values stated in acceptable metric units are to be
5.1 RockwellHardnessTester,calibratedinaccordancewith
regarded as the standard. The values given in parentheses are
the requirements of Section 7.
provided for information purposes only.
5.2 Rockwell Hardness Tester Anvil, appropriate for the
1.4 This standard does not purport to address all of the
material shall be used as the specimen base plate.
safety concerns, if any, associated wth its use. It is the
responsibility of the user of this standard to establish appro-
6. Test Specimen
priate safety and health practices and determine the applica-
6.1 The recommended test specimen shall be flat and have a
bility of regulatory limitations prior to use.
minimum thickness of 6.35 mm ( ⁄4 in.).
6.2 The test surface roughness shall not exceed 3175-nm
2. Referenced Documents
(125–µin.) arithmetical average.
2.1 ASTM Standards:
6.3 The test surface to opposite face parallelism for flat
E18 Test Methods for Rockwell Hardness and Rockwell
specimens shall be within 1 %. For all other specimen shapes,
Superficial Hardness of Metallic Materials
the test surface must be maintained normal to the direction of
E 171 Specification for Standard Atmospheres for Condi-
load application.
tioning and Testing Flexible Barrier Materials
7. Verification of Calibration
3. Summary of Test Method
7.1 Level the Rockwell hardness tester in accordance with
3.1 The specimen is held in position and the load is applied.
the manufacturer’s instructions.
Final position of the indicator on the scale is observed and
7.2 The adjustment of speed-of-load application is of great
recorded as the hardness number.
importance. Adjust the dashpot on the Rockwell tester so that
4. Significance and Use the operating handle completes its travel in 4 to 7 s with no
specimen on the machine or no load applied by the indenter to
4.1 A Rockwell L scale hardness number is a number
the anvil. The major load shall be 60 kg for this calibration.
derivedfromthenetincreaseindepthofimpressionastheload
When so adjusted, the period taken for the mechanism to come
on a 6.3500 6 0.0025 mm (0.2500 6 0.0001 in.) diameter
to a stop with the specimen in place will vary from 5 to 15 s,
steel-ball indenter is increased from a fixed 10-kg minor load
depending upon the particular specimen, the indenter, and the
to a 60-kg major load and then returned to the minor load.
load used. The operator should check the instrument manual
for this adjustment.
This test method is under the jurisdiction of ASTM Committee D02 on 7.3 Select a test block for Rockwell L scale ball-type
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
indenters and make five impressions on the test surface of the
D02.F on Manufactured Carbon and Graphite Products.
block. Compare the average of these five tests against the
Current edition approved March 10, 1998. Published December 1998. Originally
e1
hardness calibration of the block. If the error is more than 62
published as C 748 – 73. Last previous edition C 748 – 83 (Reapproved 1993) .
Annual Book of ASTM Standards, Vol 03.01.
Annual Book of ASTM Standards, Vol 15.09.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C748–98
hardness numbers, the machine or penetrator, or both, must be 11.1.1 If the table on which a Rockwell hardness tester is
checked to determine and correct the cause of error. mounted is subject to vibration, such as is experienced in the
vicinity of other machines, the tester should be effectively
8. Conditioning
protected. Mounting the hardness tester on a metal plate with
8.1 Allow the specimen(s) to reach equilibrium with room-
25-mm (1-in.) thick sponge rubber pads is recommended.
temperature air, and test under the same conditions in accor-
11.1.2 Indenter
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.

This May Also Interest You

ASTM
ASTM C714-23(Guide)
Standard Guide for Thermal Diffusivity of Carbon and Graphite by Thermal Pulse Method

SIGNIFICANCE AND USE
5.1 Thermal diffusivity is an important property required for such purposes as design applications under transient heat flow conditions, determination of safe operating temperature, process control, and quality assurance.  
5.2 The flash method is used to measure values of thermal diffusivity (α) of a wide range of solid materials. It is particularly advantageous because of the simple specimen geometry, small specimen size requirements, rapidity of measurement, and ease of handling materials having a wide range of thermal diffusivity values over a large temperature range with a single apparatus. The short measurement times involved reduce the chances of contamination and change of specimen properties due to exposure to high temperature environments.  
5.3 Thermal diffusivity results in many cases can be combined with values for specific heat (Cp) and density (ρ) to derive thermal conductivity (λ) from the relation λ = αCpρ. For guidance on converting thermal diffusivity to thermal conductivity, refer to Practice C781.  
5.4 This test method described in this guide can be used to characterize graphite for design purposes.  
5.5 Test Method E1461 is a more detailed form of this test method described in this guide and has applicability to much wider ranges of materials, applications, and temperatures.
SCOPE
1.1 This guide covers the determination of the thermal diffusivity of carbons and graphite at temperatures up to 500 °C. It is applicable only to small easily fabricated specimens. Thermal diffusivity values in the range from 0.04 cm2/s to 2.0 cm2/s are readily measurable by this guide; however, for the reason outlined in Section 7, for materials outside this range this guide may not be applicable.  
1.2 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Guide
    5 pages
    English language
    sale 15% off
  • Guide
    5 pages
    English language
    sale 15% off
ASTM
ASTM C747-23(Test Method)
Standard Test Method for Moduli of Elasticity and Fundamental Frequencies of Carbon and Graphite Materials by Sonic Resonance

SIGNIFICANCE AND USE
5.1 This test method may be used for material development, characterization, design data generation, and quality control purposes.  
5.2 This test method is primarily concerned with the room temperature determination of the dynamic moduli of elasticity and rigidity of slender rods or bars composed of homogeneously distributed carbon or graphite particles.  
5.3 This test method can be adapted for other materials that are elastic in their initial stress-strain behavior, as defined in Test Method E111.  
5.4 This basic test method can be modified to determine elastic moduli behavior at temperatures from –75 °C to +2500 °C. Thin graphite rods may be used to project the specimen extremities into ambient temperature conditions to provide resonant frequency detection by the use of transducers as described in 7.1.
SCOPE
1.1 This test method covers determination of the dynamic elastic properties of isotropic and near isotropic carbon and graphite materials at ambient temperatures. Specimens of these materials possess specific mechanical resonant frequencies that are determined by the elastic modulus, mass, and geometry of the test specimen. The dynamic elastic properties of a material can therefore be computed if the geometry, mass, and mechanical resonant frequencies of a suitable (rectangular or cylindrical) test specimen of that material can be measured. Dynamic Young's modulus is determined using the resonant frequency in the flexural or longitudinal mode of vibration. The dynamic shear modulus, or modulus of rigidity, is found using torsional resonant vibrations. Dynamic Young's modulus and dynamic shear modulus are used to compute Poisson's ratio.  
1.2 This test method determines elastic properties by measuring the fundamental resonant frequency of test specimens of suitable geometry by exciting them mechanically by a singular elastic strike with an impulse tool. Specimen supports, impulse locations, and signal pick-up points are selected to induce and measure specific modes of the transient vibrations. A transducer (for example, contact accelerometer or non-contacting microphone) senses the resulting mechanical vibrations of the specimen and transforms them into electric signals. (See Fig. 1.) The transient signals are analyzed, and the fundamental resonant frequency is isolated and measured by the signal analyzer, which provides a numerical reading that is (or is proportional to) either the frequency or the period of the specimen vibration. The appropriate fundamental resonant frequencies, dimensions, and mass of the specimen are used to calculate dynamic Young's modulus, dynamic shear modulus, and Poisson's ratio. Annex A1 contains an alternative approach using continuous excitation.
FIG. 1 Block Diagram of Typical Test Apparatus  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental 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.

  • Standard
    19 pages
    English language
    sale 15% off
  • Standard
    19 pages
    English language
    sale 15% off
ASTM
ASTM C562-23(Test Method)
Standard Test Method for Moisture in a Graphite Sample

SIGNIFICANCE AND USE
4.1 This test method is applicable only for determination of the volatile moisture content resulting from adsorption of water vapor from the atmosphere, and is not intended to give representative moisture data for graphite that has been exposed to liquid water contamination.
SCOPE
1.1 This test method provides a practical determination for the percentage of moisture in a graphite sample.  
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 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Standard
    2 pages
    English language
    sale 15% off
  • Standard
    2 pages
    English language
    sale 15% off
ASTM
ASTM C561-23(Test Method)
Standard Test Method for Ash in a Graphite Sample

SIGNIFICANCE AND USE
4.1 This test method provides a practical estimate of nonburnable residues in commercially available graphite materials. The ash values determined by this test method are of use in comparing the relative purity of various grades of graphite. To facilitate use, this test method institutes simplifications that preclude the ability to determine absolutely the ash values of the test graphite material due to uncontrolled sources of trace contamination.  
4.2 This test method is not intended for use in determining the ash content of purified graphites, for example, nuclear materials. The relationship between the mineral content of a graphite sample and the ash content of that sample is unknown and is not determined by the application of this test method.
SCOPE
1.1 This test method provides a practical determination for the ash content in a graphite sample.  
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 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Standard
    3 pages
    English language
    sale 15% off
  • Standard
    3 pages
    English language
    sale 15% off
ASTM
ASTM D7846-21(Practice)
Standard Practice for Reporting Uniaxial Strength Data and Estimating Weibull Distribution Parameters for Advanced Graphites

SIGNIFICANCE AND USE
5.1 Two- and three-parameter formulations exist for the Weibull distribution. This practice is restricted to the two-parameter formulation. An objective of this practice is to obtain point estimates of the unknown Weibull distribution parameters by using well-defined functions that incorporate the failure data. These functions are referred to as estimators. It is desirable that an estimator be consistent and efficient. In addition, the estimator should produce unique, unbiased estimates of the distribution parameters (6). Different types of estimators exist, such as moment estimators, least-squares estimators, and maximum likelihood estimators. This practice details the use of maximum likelihood estimators.  
5.2 Tensile and flexural specimens are the most commonly used test configurations for graphite. The observed strength values depend on specimen size and test geometry. Tensile and flexural test specimen failure data for a nearly isotropic graphite (7) is depicted in Fig. 1. Since the failure data for a graphite material can be dependent on the test specimen geometry, Weibull distribution parameter estimates (m, Sc) shall be computed for a given specimen geometry.
FIG. 1 Failure Strengths for Tensile Test Specimens (left) and Flexural Test Specimens (right) for a Nearly Isotropic Graphite (7)  
5.3 The bias and uncertainty of Weibull parameters depend on the total number of test specimens. Variability in parameter estimates decreases exponentially as more specimens are collected. However, a point of diminishing returns is reached where the cost of performing additional strength tests may not be justified. This suggests a limit to the number of test specimens for determining Weibull parameters to obtain a desired level of confidence associated with a parameter estimate. The number of specimens needed depends on the precision required in the resulting parameter estimate or in the resulting confidence bounds. Details relating to the computation of confidence bo...
SCOPE
1.1 This practice covers the reporting of uniaxial strength data for graphite and the estimation of probability distribution parameters for both censored and uncensored data. The failure strength of graphite materials is treated as a continuous random variable. Typically, a number of test specimens are failed in accordance with the following standards: Test Methods C565, C651, C695, C749, Practice C781 or Guide D7775. The load at which each specimen fails is recorded. The resulting failure stresses are used to obtain parameter estimates associated with the underlying population distribution. This practice is limited to failure strengths that can be characterized by the two-parameter Weibull distribution. Furthermore, this practice is restricted to test specimens (primarily tensile and flexural) that are primarily subjected to uniaxial stress states.  
1.2 Measurements of the strength at failure are taken for various reasons: a comparison of the relative quality of two materials, the prediction of the probability of failure for a structure of interest, or to establish limit loads in an application. This practice provides a procedure for estimating the distribution parameters that are needed for estimating load limits for a particular level of probability of failure.  
1.3 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.

  • Standard
    9 pages
    English language
    sale 15% off
  • Standard
    9 pages
    English language
    sale 15% off
ASTM
ASTM D7542-21(Test Method)
Standard Test Method for Air Oxidation of Carbon and Graphite in the Kinetic Regime

SIGNIFICANCE AND USE
5.1 This test method can be used to measure the rate of oxidation for various grades of manufactured carbon and graphite in standard conditions, and can be used for quality control purposes.  
5.2 The following conditions are standardized in this test method: size and shape of the graphite specimens; their placement in the vertical furnace with upwards air flow; the method for continuous weight variation measurement using an analytical scale with under-the-scale port; the air flow rate, which must be high enough to ensure that oxidation is not oxygen-starved at the highest temperature used; the initial and final points on the weight loss curve used for calculation of oxidation rate.  
5.3 This test method also provides kinetic parameters (apparent activation energy and logarithm of pre-exponential factor) for the oxidation reaction, and a standard oxidation temperature. The results characterize the effect of temperature on oxidation rates in air, and the oxidation resistance of machined carbon or graphite specimens with standard size and shape, in the kinetic, or chemically controlled, oxidation regime. This information is useful for discrimination between material grades with different impurity levels, grain size, pore structure, degree of graphitization, or antioxidation treatments, or a combination thereof.  
5.4 Accurately determined kinetic parameters, like activation energy and logarithm of pre-exponential factor, can be used for prediction of oxidation rates in air as a function of temperature in conditions similar to those of this test method. However, extrapolation of such predictions outside the temperature range where Arrhenius plots are linear (outside the kinetic or chemically controlled regime of oxidation) should be made with extreme caution. In conditions where (1) oxidation rates become controlled by a mechanism other than chemical reactions (such as in-pore diffusion or boundary transport of the oxidant gas), or (2) the oxidant supply rate is no...
SCOPE
1.1 This test method recommends a standard procedure for measuring oxidation rates in air of various grades of nuclear graphite and/or manufactured carbon. Following the standard procedure recommended here, one can obtain kinetic parameters that characterize the oxidation resistance in standard conditions of tested materials and that can be used to for materials selection and qualification, and for quality control purposes in the fabrication process.  
1.2 This test method covers the rate of oxidative weight loss per exposed nominal geometric surface area, or per initial weight of machined test specimens of standard size and shape, or both. The test is valid in the temperature range where the rate of air oxidation of graphite and manufactured carbon is limited by reaction kinetics.  
1.3 This test method also provides a standard oxidation temperature (as defined in 3.1.7), and the kinetic parameters of the oxidation reaction, namely the apparent activation energy and the logarithm of pre-exponential factor in Arrhenius equation. The kinetic parameters of Arrhenius equation are calculated from the temperature dependence of oxidation rates measured over the temperature range where Arrhenius plots (as defined in 3.1.8) are linear, which is defined as the “kinetic” or “chemical control” oxidation regime. For typical nuclear grade graphite materials it was found that the practical range of testing temperatures is from about 500 °C to 550 °C up to about 700 °C to 750 °C.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international s...

  • Standard
    13 pages
    English language
    sale 15% off
  • Standard
    13 pages
    English language
    sale 15% off
ASTM
ASTM C1179-21(Test Method)
Standard Test Method for Oxidation Mass Loss of Manufactured Carbon and Graphite Materials in Air

SIGNIFICANCE AND USE
3.1 This test method is primarily concerned with the oxidation mass loss of manufactured carbon and graphite materials in air at temperatures from 371 °C to 677 °C.  
3.2 The test method will provide acceptable results at preselected test temperatures that yield less than 10 % mass loss in 100 h. These results can be used to determine relative service temperatures.
SCOPE
1.1 This test method provides a comparative oxidation mass loss of manufactured carbon and graphite materials in air.  
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 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Standard
    4 pages
    English language
    sale 15% off
  • Standard
    4 pages
    English language
    sale 15% off
ASTM
ASTM D8091-21(Guide)
Standard Guide for Impregnation of Graphite with Molten Salt

SIGNIFICANCE AND USE
5.1 The molten salt reactor is a nuclear reactor which uses graphite as reflector and structural material and fluoride molten salt as coolant. The graphite components will be submerged in the molten salt during the lifetime of the reactor. The porous structure of graphite may lead to molten salt permeation, which can affect the thermal and mechanical properties of graphite. Consequently, it is important to assess the effect of impregnation of molten salt on the properties of the as-manufactured graphite material.  
5.2 The purpose of this guide is to report considerations that should be included in the preparation of graphite specimens representative of that after exposure to a molten salt environment. The degree to which the molten salt will infiltrate the graphite will depend upon a number of factors, including the type of graphite and the type and extent of porosity, the properties of the molten salt, the impregnation pressure and temperature, and the duration of the exposure of the graphite to the molten salt.  
5.3 The user of this guide will need to select impregnation parameters sufficiently representative of those in a molten salt reactor based on parameters provided by the designer. Alternatively, the user may select a standard set of impregnation conditions to allow comparisons across a range of graphites.  
5.4 This guide is not intended to be prescriptive. A typical apparatus and associated procedure are described. Some indication of the sensitivity of the procedure to graphite type and impregnation conditions is given in He, et al.5  
5.5 There are four major practical issues that must be addressed during the impregnation process:  
5.5.1 The density of molten salt is greater than that of graphite. A specially designed tool is required to submerge graphite samples in the molten salt during the impregnation process.  
5.5.2 Some molten salts (for example, FLiBe) are poisonous and it is therefore necessary to provide containment by performing proced...
SCOPE
1.1 This guide covers procedures for the impregnation of graphite with molten salt under a consistent pressure and temperature. Such procedures are necessary if the user wishes to prepare graphite specimens for testing that represent material that has been exposed to a molten salt environment in a molten salt nuclear reactor. The user will need to ensure that impregnation temperature and pressure conditions reflect those pertaining to the molten salt environment, noting that the properties of the material will change once it becomes irradiated.
Note 1: The term impregnation is used throughout this guide as this is the correct term for the described process. Other terms such as infiltration and intrusion may be encountered by the user in other texts and the term intrusion is commonly used to describe penetration of open porosity in graphite in a molten salt reactor environment.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this guide.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Guide
    5 pages
    English language
    sale 15% off
  • Guide
    5 pages
    English language
    sale 15% off
ASTM
ASTM D8377-21a(Guide)
Standard Guide for High Temperature Strength Measurements of Graphite Impregnated with Molten Salt

SIGNIFICANCE AND USE
5.1 The Molten Salt Reactor is a nuclear reactor which uses graphite as reflector and structural material, and molten salt as coolant. The graphite components will be submerged in the molten salt during the lifetime of the reactor. The porous structure of graphite may lead to molten salt permeation, which can affect the thermal and mechanical properties of graphite. Consequently, it may be necessary to measure the various strengths of the manufactured graphite materials after impregnation with molten salt and before exposure to the reactor environment in a range of test configurations in order for designers or operators to assess their performance.
Note 1: Depending upon the salt selected for the reactor, there may be some chemical reaction between the salt and the graphite that could affect properties. The user should establish, prior to following this guide, that any interactions between the molten salt and graphite are understood and any implications for the validity of the strength tests have been assessed.  
5.2 For gas-cooled reactors, the strength of a graphite specimen is usually measured at room temperature. However, for molten salt reactors, the operating temperature of the reactor must be higher than the melting temperature of the salt, and so the salt will be in solid state at room temperature. Consequently, room temperature measurements may not be representative of the performance of the material at its true operating conditions. It is therefore necessary to measure the strength at an elevated temperature where the salt is in liquid form.
Note 2: Users should be aware that a small increase in graphite strength is expected with increasing temperature. Testing at the plant operating temperature will eliminate this small uncertainty.  
5.3 The purpose of this guide is to provide considerations, which should be included in testing graphite specimens impregnated with molten salt at elevated temperature.  
5.4 For the test results to be meaningful, the...
SCOPE
1.1 This guide covers the best practice for strength measurements at elevated temperature of graphite impregnated with molten salt.  
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 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Guide
    5 pages
    English language
    sale 15% off
  • Guide
    5 pages
    English language
    sale 15% off
ASTM
ASTM C695-21(Test Method)
Standard Test Method for Compressive Strength of Carbon and Graphite

SIGNIFICANCE AND USE
4.1 Carbon and graphite can usually support higher loads in compression than in any other mode of stress. This test, therefore, provides a measure of the maximum load-bearing capability of carbon and graphite objects.
SCOPE
1.1 This test method covers the determination of the compressive strength of carbon and graphite at room temperature.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Standard
    4 pages
    English language
    sale 15% off
  • Standard
    4 pages
    English language
    sale 15% off