1、Designation: C 1039 85 (Reapproved 2005)An American National StandardStandard Test Methods forApparent Porosity, Apparent Specific Gravity, and BulkDensity of Graphite Electrodes1This standard is issued under the fixed designation C 1039; the number immediately following the designation indicates th
2、e year oforiginal adoption or, in the case of revision, 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 These test methods cover the determination of app
3、arentporosity, apparent specific gravity, and bulk density of corestaken from graphite electrodes manufactured for use in electricarc furnaces. (See also C 559 and C 838.)1.2 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the
4、 user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 559 Test Method for Bulk Density by Physical Measure-ment of Manufactured Carbon and Graphite ArticlesC 783 Pr
5、actice for Core Sampling of Graphite ElectrodesC 838 Test Method for Bulk Density of As-ManufacturedCarbon and Graphite Shapes3. Significance and Use3.1 The results of these test methods can be used as a qualitycontrol or quality assurance check of electrodes either duringtheir manufacture or at the
6、 users location. The results of thesemethods tend to be operator-sensitive, therefore, care must betaken in the execution of the test in order to obtain reproducibleresults.4. Apparatus4.1 Drying Oven.4.2 Analytical Balance, capable of weighing to 0.1 g.4.3 Autoclave or Pressure Vessel, capable of w
7、ithstandingone atmosphere externally and designed to withstand at least448 to 483 kPa (65 to 70 psi) internal pressure.4.3.1 The pressure vessel shall be provided with an opentopcontainer to hold the specimens and a means of introducingwater around the specimens while specimens are being held atlow
8、pressure.4.4 Vacuum Pump.4.5 Wire Loop, Halter or Stirrup, fabricated with 22 AWG(9.643 mm) copper wire shall be provided for determiningsuspended weight.4.6 Smooth Linen or Cotton Cloth.5. Test Specimens and Sampling5.1 Electrodes can be sampled using Practice C 783 thatresult in a specimen with ap
9、proximately 50 mm (2 in.)diameter and 191 mm (712 in.) long or a specimen ofequivalent volume.5.2 If sizes and shapes which are different from thosedescribed in 5.1, these shall be included in the report.5.3 For each test, select at least five electrodes, at random,to represent a lot. The lot size w
10、ill be determined by agreementof the parties desiring the tests.6. Calibration6.1 Prior to obtaining the suspended weights of the speci-mens, the balance shall be adjusted to zero with the wire stirrupsuspended from the balance and immersed into a container ofthe liquid to the same depth in the liqu
11、id as occurs when aspecimen is in place.7. Procedure7.1 Determinations of Dry Weight, D:7.1.1 Dry the test specimens to constant weight by heatingto 100 to 110C (212 to 230F). Cool and determine the dryweight, D, in grams to the nearest 0.1 g. If the time betweendrying and weighing exceeds 8 h, the
12、specimens must be storedin a desiccator.7.1.2 The determination of dry weight may be done eitherbefore or after the saturation operation. If the specimen isfriable or there is evidence that particles have broken looseduring the saturation operation, the dry weight shall beobtained after the suspende
13、d and saturated weights have beendetermined. Drying as described in 7.1.1 must be carried out.7.2 Saturation:1These test methods are under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.F0 on Manufactured Carbon and Grap
14、hite Products.Current edition approved June 1, 2005. Published August 2005. Originallyapproved in 1985. Last previous edition approved in 2000 as C 103985(2000).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book o
15、f ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2.1 Using the pressure vessel described in 4.3, place thespecimens in the open-top
16、container inside the vessel. Closeand seal the vessel and pump down at least to 133 Pa (1 mmHg) and maintain this pressure for 30 min.7.2.2 Slowly introduce water (preferably distilled water)until the specimens are covered with at least 40 mm (1.5 in.) ofwater. Continue to pump for an additional 5 m
17、in.NOTE 1Sufficient water must be provided above the specimens tosupply enough water to fill the open pores of the specimens duringpressurization. If after pressurization, one or more specimens are exposedto air above the water, these specimens must be dried and process repeated(7.1.1).7.2.3 After t
18、he evacuation process is completed, close thevacuum line and introduce air pressure. Pressurize to 207 6 7kPa (30 6 1 psi) gage pressure and hold for 4 h. Following thisperiod of time return the vessel to atmospheric pressure.7.3 Determination of Suspended Weight, S:7.3.1 Within1hofthetime the vesse
19、l returns to atmo-spheric pressure, the suspended weights and saturated weightsmust be obtained.7.3.2 Place the container used in the vacuum-pressurevessel near the immersion container to facilitate rapid transferto the weighing stirrup (see 4.5).7.3.3 Obtain the suspended weight, S, to the nearest
20、0.1 g, ofeach specimen. The specimens can be transferred through airbut the transfer must be made quickly. Following the weighing,each specimen should be returned to a separate container ofwater or the saturated weight, W, should be obtained immedi-ately according to 7.4.7.4 Determination of Saturat
21、ed Weight, W:7.4.1 After determining the suspended weight, blot eachspecimen lightly with a moistened smooth linen or cotton clothto remove all drops of water from the surface and weigh in air,to the nearest 0.1 g, to obtain the saturated weight, W. The clothmust be prepared by previously saturating
22、 it with water andthen pressing only enough to remove the water which woulddrip from the cloth. Avoid excessive blotting or rubbing whichwill remove water from the pores of the specimen.8. Calculation8.1 Exterior VolumeObtain the exterior volume by sub-tracting the suspended weight from the saturate
23、d weight.V, cm35 W 2 S (1)where:V = exterior volume, cm3,W = saturated weight, g, andS = suspended weight, g.NOTE 2This assumes that one cubic centimetre of water weighs 1 g.This is true within about 3 parts in 1000 for water at 20 to 25C (68 to77F).8.2 Volume of Open PoresObtain the volume of openp
24、ores by subtracting the dry weight, D, from the saturatedweight, W.Volume of open pores, cm35 W 2 D (2)8.3 Volume of Impervious PortionObtain the volume ofimpervious portion by subtracting the suspended weight, S,from the dry weight, D.Volume of impervious portion, cm35 D 2 S (3)8.4 Apparent Porosit
25、y, PThe apparent porosity, P,isexpressed as a percentage of the volume of open pores to theexterior volume, and may be calculated as follows:P,%5 W 2 D!/V# 3 100 5 W 2 D!/W 2 S!#3 100 (4)8.5 Bulk Density, BThe bulk density of a specimen, B,ingrams per cubic centimetre, is its mass per unit volume,in
26、cluding pores. Calculate as follows:B, g/cm35 D/V 5 D/W 2 S! (5)If bulk density in pounds per cubic foot is desired, multiplyby 62.4.8.6 Apparent Specific Gravity, TCalculate the apparentspecific gravity, T, of that portion of the specimen which isimpervious to water under these test conditions as f
27、ollows:T 5 D/D 2 S! (6)9. Report9.1 Report sizes of specimens tested.9.2 Report the values of all properties for individual speci-mens and the averages.9.3 Calculate apparent porosity values to one decimal place.9.4 Calculate bulk density and apparent specific gravityvalues to two decimal places.10.
28、 Precision and Bias10.1 Interlaboratory TestsAn interlaboratory study usingthe vacuum-pressure method, was conducted among six labo-ratories who tested three specimens of each of three graphitematerials representing a range of apparent porosities and bulkdensities. The three materials were chosen fr
29、om premiumgrade electrodes, regular grade electrodes, and connectingnipples.10.2 PrecisionTables 1-3 show the applicable data forprecision in terms of percent apparent porosity (Table 1),grams per cubic centimetre of bulk density (Table 2) andapparent specific gravity (Table 3).10.3 BiasA bias state
30、ment is not possible because nostandard reference materials are available.11. Keywords11.1 bulk; carbon; density; electrodes; graphite; physical;porosity; specific gravityTABLE 1 Precision of Apparent Porosity, PercentStandard DeviationsMaterial Average Within Labs Between Labs1 23.1 0.70 0.712 18.6
31、 1.21 0.913 13.1 1.37 0.33C 1039 85 (2005)2ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and
32、the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision
33、 of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shou
34、ldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtai
35、ned by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 2 Precision of Bulk Density, Grams per CubicCentimetreStandard DeviationsMaterial Average Within Labs Between Labs1 1.61 0.011 0.0052 1.70 0.018 0.0103 1.81 0.025 0.014TABLE 3 Precision of Apparent Specific GravityStandard DeviationsMaterial Average Within Labs Between Labs1 2.10 0.008 0.0182 2.09 0.019 0.0263 2.09 0.011 0.018C 1039 85 (2005)3
