1、Designation: D 7219 05An American National StandardStandard Specification forIsotropic and Near-isotropic Nuclear Graphites1This standard is issued under the fixed designation D 7219; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the classification, processing,and properties of nuclear grade graphite billet
3、s with dimen-sions sufficient to meet the designers requirements for fuelelements, moderator or reflector blocks, in a high temperaturegas cooled reactor. The graphite classes specified here wouldbe suitable for reactor core applications where neutron irradia-tion induced dimensional changes are a s
4、ignificant designconsideration.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of
5、this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 709 Terminology Relating to Manufactured Carbon andGraphiteC 781 Practice for Testing Graphite and Boronated Graphi
6、tefor High-Temperature Gas-Cooled Nuclear ReactorsC 838 Test Method for Bulk Density of As-ManufacturedCarbon and Graphite ShapesC 1233 Practice for Determining Equivalent Boron Con-tents of Nuclear MaterialsD 346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisD 2638 T
7、est Method for Real Density of Calcined Petro-leum Coke by Helium Pycnometer2.2 ASME Standard:NQA-1 Quality Assurance Program Requirements forNuclear Facilities33. Terminology3.1 DefinitionsDefinitions relating to this specification aregiven in Terminology C 709.3.2 Definitions of Terms Specific to
8、This Standard:3.2.1 apparent porosityratio of the volume of open poresto the exterior volume expressed as a percentage.3.2.2 baking/re-baking chargethe number of billets in abaking/re-baking furnace run.3.2.3 bulk densitythe mass of a unit volume of materialincluding both permeable and impermeable v
9、oids.3.2.4 extrusion forming lotthe number of billets of thesame size extruded in an uninterrupted sequence.3.2.5 green batchthe mass of coke, recycle green mix,recycle graphite, and pitch that is required to produce aforming lot.3.2.6 graphite billetan extruded, molded, or iso-moldedgraphite artifa
10、ct with dimensions sufficient to meet the design-ers requirements for reactor components.3.2.7 graphite gradethe designation given to a materialby a manufacturer such that it is always reproduced to the samespecification and from the same raw materials and mixformulation.3.2.8 graphitization charget
11、he number of billets in agraphitizing furnace run.3.2.9 high purity nuclear graphitenuclear graphite whoseBoron Equivalent content is less that 2 ppm.3.2.10 impregnation chargethe number of billets in anautoclave cycle.3.2.11 isotropic nuclear graphitea graphite in which theisotropy ratio based on t
12、he coefficient of thermal expansion is1.00 to 1.10.3.2.12 low purity nuclear graphitenuclear graphite whoseBoron Equivalent content is greater than 2 ppm but less that 10ppm.3.2.13 mix formulationthe percentages of each specifi-cally sized filler used to manufacture a graphite grade.1This specificat
13、ion is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.F0 on Manufactured Carbon and Graphite Products.Current edition approved Nov. 1, 2005. Published December 2005.2For referenced ASTM standards, visit the ASTM we
14、bsite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Av
15、e., New York, NY 10016-5990.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.14 molding forming lotthe number of billets moldedfrom a molding powder lot.3.2.15 molding powder lota sufficient quantity of re-milled and blended green
16、 batch produced from an uninter-rupted flow of raw materials, or produced in a sequence ofidentical materials batches, to produce a molding forming lot.3.2.16 near isotropic nuclear graphitea graphite in whichthe isotropy ratio based on the coefficient of thermal expansionis 1.10 to 1.15.3.2.17 nucl
17、ear graphite classthe designation of a nucleargraphite based upon its forming method, isotropy, purity anddensity (see Table 1).3.2.18 production lota specified number of billets made inaccordance with this specification as determined by the pur-chaser.3.2.19 purification chargethe number of billets
18、 in a puri-fication run.3.2.20 recycle green mixground non-baked billets or non-formed formulation manufactured in compliance with the mixformulation specified here.4. Significance and Use4.1 The purpose of this specification is to document theminimum acceptable properties and levels of quality assu
19、ranceand traceability for isotropic and near-isotropic nuclear gradegraphites.5. Materials and Manufacture5.1 Nuclear Graphite ClassesSee Table 1.5.2 Raw Materials:5.2.1 Fillers:5.2.1.1 The filler shall consist of a near-isotropic or isotro-pic coke derived from a petroleum oil or coal tar.5.2.1.2 T
20、he coke shall have a coefficient of linear thermalexpansion (CTE), determined in accordance with PracticeC 781 and measured over the temperature range 25 to 500C,of between 3.5 3 10-6and 5.5 3 10-6C-1.5.2.1.3 The coke shall be sampled and distributed as de-scribed in Table 3.5.2.1.4 Graphite manufac
21、tured in compliance with thisspecification but failing to meet the property requirements ofSections 6 and 7 may be used as recycle material in the mixformulation.5.2.1.5 Recycle green mix manufactured from raw materialsin compliance with this specification may be used in the mixformulation.5.2.1.6 T
22、he maximum filler particle size used in the mixformulation shall be 1.68 mm.5.3 BinderThe binder shall consist of coal tar pitch. Thespecific binder used shall be identified to the purchaser and betraceable through the forming lot.5.4 ImpregnantThe impregnant shall consist of a petro-leum or coal ta
23、r pitch and be traceable through the impregna-tion step.5.5 Manufacturing or Processing AdditivesAdditives (forexample, extrusion aids) may be used to improve the process-ing, quality and properties of the product, but only with theconsent and approval of the purchaser, and they must betraceable thr
24、ough the forming lot.5.6 Manufacture:5.6.1 FormulationThe mix formulation (as defined in3.2.13) and recycle green mix fraction (as defined in 3.2.20)inthe filler shall be recorded. This information shall be reportedto the purchaser if requested.5.6.2 FormingThe green carbon mix may be formed byextru
25、sion, molding (including vibrationally molding), or iso-molding.TABLE 1 ASTM Standard Classes of Nuclear GraphiteClassACTE Isotropy RatioB(aAG/aWG)PurityBulk Density,Cg/cm3(min)Class DesignationAsh Content,Bppm (max)Boron Equivalent,Dppm (max)Isomolded, isotropicHigh Purity 1.0-1.1 300 2 1.7 IIHPIso
26、molded, isotropicLow Purity 1.0-1.1 1000 10 1.7 IILPIsomolded, near-isotropicHigh Purity 1.1-1.15 300 2 1.7 INHPIsomolded, near-isotropicLow Purity 1.1-1.15 1000 10 1.7 INLPExtruded, isotropicHigh Purity 1.0-1.1 300 2 1.7 EIHPExtruded, isotropicLow Purity 1.0-1.1 1000 10 1.7 EILPExtruded, near-isotr
27、opicHigh Purity 1.1-1.15 300 2 1.7 ENHPExtruded, near-isotropicLow Purity 1.1-1.15 1000 10 1.7 ENLPMolded, isotropicHigh Purity 1.0-1.1 300 2 1.7 MIHPMolded, isotropicLow Purity 1.0-1.1 1000 10 1.7 MILPMolded, near-isotropicHigh Purity 1.1-1.15 300 2 1.7 MNHPMolded, near-isotropicLow Purity 1.1-1.15
28、 1000 10 1.7 MNLPAThese classes may be further modified by the grain size as defined in Terminology C 709.BDetermined in accordance with Practice C 781.CDetermined in accordance with Test Method C 838.DDetermined in accordance with Practice C 1233.TABLE 2 ASTM Graphite Grain Size Definitions fromTer
29、minology C 709Graphite DesignationDefinition ofGrains in the Starting Mix that are:AMedium Grained Generally4mmFine Grained Generally 100 mSuperfine Grained Generally 50 mUltrafine Grained Generally 10 mMicrofine Grained Generally2mAGrain size as defined in Terminology C 709.D72190525.6.3 Graphitiza
30、tion TemperatureThe graphitization tem-perature shall be determined on each billet using the proceduredescribed in Practice C 781. Each billet tested in accordancewith Practice C 781 shall have a Specific Electrical Resistivity(SER) corresponding to a graphitization temperature of at least2700C.6. C
31、hemical Properties6.1 Each graphite billet/production lot sampled in accor-dance with Section 11 shall conform to the requirements forchemical purity specified in Table 4 or Table 5, and to therequirements of the purchaser.6.2 The boron equivalent shall be calculated in accordancewith Practice C 123
32、3. The concentrations of at least thefollowing elements shall be determined and used in thecalculation: Boron, Cadmium, Chlorine, Cobalt, Dysprosium,Europium, Gadolinium, Lithium, Manganese, Nickel, Sa-marium, Silver, Titanium, Tungsten, and Vanadium. Specifiedboron equivalent limits are given in Ta
33、ble 1.6.3 Table X1.1 contains a list of chemical impurities typi-cally found in graphite. The impurities are categorized asneutron absorbing impurities, oxidation promoting catalysts,activation relevant impurities, metallic corrosion relevant im-purities, and fissile/fissionable elements. The sugges
34、ted limitsrepresent the reactor designers preferences for chemical pu-rity.7. Physical and Mechanical Properties7.1 Each graphite billet/production lot sampled in accor-dance with Section 11 shall conform to the requirements forphysical properties prescribed in Table 1 and Tables 6-11 forthe appropr
35、iate nuclear graphite class, and to the requirementsof the purchaser. Table X1.2 is a summary table of theproperties reported in Tables 6-11.8. Other Requirements8.1 The graphitized billets shall be handled and stored insuch a manner that they are protected from contaminants otherthan ambient air.8.
36、2 Each graphite billet shall be marked with a unique billetidentification number. Each billet shall be traceable throughthese identifying numbers to each of the following:8.2.1 Formulation designation,8.2.2 Coke batch,8.2.3 Recycle graphite batch,8.2.4 Forming lot,8.2.5 Molding powder lot,8.2.6 Baki
37、ng charge,8.2.7 Impregnant charge,8.2.8 Graphitizing charge,8.2.9 Position of billet in graphitization furnace,8.2.10 Purification step (if performed),TABLE 3 Inspection Sampling and Testing of Filler CokesRaw Material Inspection Plan Sampling Procedure Tests and Test MethodsFiller coke A representa
38、tive sample of thecoke shall be taken prior to themixing step of manufactureSample in accordance with Practice D 346 The procedure in Practice C 781 shall be used toprepare test specimens for the measurement ofcoke CTE1. A sufficient sample for preparation of CTE testspecimens2. A sufficient sample
39、will be taken for additionaltesting. This sample shall be retained for aperiod specified by the graphite purchaserMeasure the coke real density in accordance withTest Method D 2638TABLE 4 Chemical Purity Requirements for HP ClassNuclear GraphiteTest Practice Specification (ppm)Ash Content C 781 300
40、maximumChemical Impurities Ca C 781 30Chemical Impurities Co C 781 0.1Chemical Impurities Fe C 781 30Chemical Impurities Cs C 781 0.1Chemical Impurities V C 781 50Chemical Impurities Ti C 781 50Chemical Impurities Li C 781 0.2Chemical Impurities Sc C 781 0.1Chemical Impurities Ta C 781 0.1Boron Equi
41、valent C 1233 2 maximumChemical Impurities N C 781 to be determinedARelative Oxidation Rate in Air C 781 to be determinedAAData are not currently available to establish this value.TABLE 5 Chemical Purity requirements for LP ClassNuclear GraphiteTest Practice Specification (ppm)Ash Content C 781 1000
42、 maximumChemical Impurities Ca C 781 100Chemical Impurities Co C 781 0.3Chemical Impurities Fe C 781 100Chemical Impurities Cs C 781 0.3Chemical Impurities V C 781 250Chemical Impurities Ti C 781 150Chemical Impurities Li C 781 0.6Chemical Impurities Sc C 781 0.3Chemical Impurities Ta C 781 0.3Boron
43、 Equivalent C 1233 10 maximumChemical Impurities N C 781 to be determinedARelative Oxidation Rate in Air C 781 to be determinedAAData are not currently available to establish this value.TABLE 6 Physical and Mechanical Properties for NuclearGraphite Classes IIHP and IILPTestAPractice SpecificationApp
44、arent Porosity C 781 14 % maxThermal Conductivity at 25C, AG C 781 90 W/mK minCoefficient of Thermal Expansion(25-500C), WGC 781 3.5-6.0 3 10-6C-1Tensile Strength, WG C 781 22 MPa minFlexural Strength, WG C 781 35 MPa minCompressive Strength, WG C 781 65 MPa minDynamic Elastic Modulus, WG C 781 15 G
45、Pa maxDynamic Elastic Modulus, WG C 781 8 GPa minStress-Strain Response and Modulusof Elasticity, WGC 781 7 GPa minStrain to Failure, WG C 781 0.3 % minFracture Toughness, WG C 781 0.8 MPa=mminWeibull Modulus, WG C 781 15 minWeibull Characteristic Value, WG C 781 to be determinedBAWG = With Grain; A
46、G = Against Grain.BData are not currently available to establish this value.D72190538.2.11 Binder pitch,8.2.12 Impregnant pitch, and8.2.13 Additives (if used).9. Dimensions9.1 Graphite billet dimensions are typically 0.4 to 0.6 mdiameter (extruded) or thickness (molded/extruded) or 0.6 by0.6 m cross
47、-section (iso-molded) and 0.75 to 3.0 m length.10. Workmanship, Finish and Appearance10.1 Graphitized billets shall be brushed clean after removalfrom the graphitization furnace.11. Sampling and Cutting11.1 Table 12 describes the sampling requirements for thegraphite grade lots and billets. A statis
48、tical sampling plan shallbe developed by the supplier and agreed with the purchaser.The plan shall describe the number of graphite billets to besampled and the frequency of sampling. The following mini-mum sampling frequencies are recommended:11.1.1 Sample 100 % of the first 10 production billets.11
49、.1.2 Sample 5 % of the next 100 production billets.11.1.3 Sample 1 % of the next 1000 production billets.TABLE 7 Physical and Mechanical Properties for NuclearGraphite Classes INHP and INLPTestAPractice SpecificationApparent Porosity C 781 14 % maxThermal Conductivity at 25C, AG C 781 80 W/mK minCoefficient of Thermal Expansion(25-500C), WGC 781 3.5-6.0 3 10-6C-1Tensile Strength, WG C 781 20 MPa minFlexural Strength, WG C 781 30 MPa minCompressive Strength, WG C 781 60 MPa minDynamic Elas
