1、Designation: C1039 85 (Reapproved 2015) An American National StandardStandard Test Methods forApparent Porosity, Apparent Specific Gravity, and BulkDensity of Graphite Electrodes1This standard is issued under the fixed designation C1039; the number immediately following the designation indicates the
2、 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the determination of appar
3、entporosity, apparent specific gravity, and bulk density of corestaken from graphite electrodes manufactured for use in electricarc furnaces. (See also C559 and C838.)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
4、standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Sta
5、ndards:2C559 Test Method for Bulk Density by Physical Measure-ments of Manufactured Carbon and Graphite ArticlesC783 Practice for Core Sampling of Graphite ElectrodesC838 Test Method for Bulk Density of As-ManufacturedCarbon and Graphite Shapes3. Significance and Use3.1 The results of these test met
6、hods can be used as a qualitycontrol or quality assurance check of electrodes either duringtheir manufacture or at the 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. Appara
7、tus4.1 Drying Oven.4.2 Analytical Balance, capable of weighing to 0.1 g.4.3 Autoclave or Pressure Vessel, capable of withstandingone atmosphere externally and designed to withstand at least448 kPa to 483 kPa internal pressure.4.3.1 The pressure vessel shall be provided with an opentopcontainer to ho
8、ld the specimens and a means of introducingwater around the specimens while specimens are being held atlow 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. Tes
9、t Specimens and Sampling5.1 Electrodes can be sampled using Practice C783 thatresult in a specimen with approximately 50 mm diameter and191 mm long or a specimen of equivalent 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
10、 each test, select at least five electrodes, at random,to represent a lot. The lot size will be determined by agreementof the parties desiring the tests.6. Calibration6.1 Prior to obtaining the suspended weights of thespecimens, the balance shall be adjusted to zero with the wirestirrup suspended fr
11、om the balance and immersed into acontainer of the liquid to the same depth in the liquid as occurswhen a specimen is in place.7. Procedure7.1 Determinations of Dry Weight, D:7.1.1 Dry the test specimens to constant weight by heatingto 100 C to 110 C. Cool and determine the dry weight, D,ingrams to
12、the nearest 0.1 g. If the time between drying andweighing exceeds 8 h, the specimens must be stored in adesiccator.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 t
13、he saturation operation, the dry weight shall be1These test methods are under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.F0 on Manufactured Carbon and Graphite Products.Current edition approved Oct. 1,
14、 2015. Published December 2015. Originallyapproved in 1985. Last previous edition approved in 2010 as C1039 85 (2010)1.DOI: 10.1520/C1039-85R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards v
15、olume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1obtained after the suspended and saturated weights have beendetermined. Drying as described in 7.1.1 mu
16、st be carried out.7.2 Saturation:7.2.1 Using the pressure vessel described in 4.3, place thespecimens in the open-top 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 distill
17、ed water)until the specimens are covered with at least 40 mm of water.Continue to pump for an additional 5 min.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 specimen
18、s are exposedto air above the water, these specimens must be dried and process repeated(7.1.1).7.2.3 After the evacuation process is completed, close thevacuum line and introduce air pressure. Pressurize to 207 kPa6 7 kPa gauge pressure and hold for 4 h. Following this periodof time return the vesse
19、l to atmospheric pressure.7.3 Determination of Suspended Weight, S:7.3.1 Within 1 h of the time the vessel 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 facilit
20、ate rapid transferto the weighing stirrup (see 4.5).7.3.3 Obtain the suspended weight, S, to the nearest 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
21、or the saturated weight, W, should be obtained immedi-ately according to 7.4.7.4 Determination of Saturated 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
22、 the nearest 0.1 g, to obtain the saturated weight, W. The clothmust be prepared by previously saturating 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. Calcul
23、ation8.1 Exterior VolumeObtain the exterior volume by sub-tracting the suspended weight from the saturated 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 a
24、bout 3 parts in 1000 for water at 20 C to 25 C.8.2 Volume of Open PoresObtain the volume of openpores 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
25、weight, S,from the dry weight, D.Volume of impervious portion, cm35 D 2 S (3)8.4 Apparent Porosity, 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# 3100 5 W 2 D!/W 2 S!# 3100 (4)8.5 Bulk Density,
26、 BThe bulk density of a specimen, B,ingrams per cubic centimetre, is its mass per unit volume,including pores. Calculate as follows:B, g/cm35 D/V 5 D/W 2 S! (5)8.6 Apparent Specific Gravity, TCalculate the apparentspecific gravity, T, of that portion of the specimen which isimpervious to water under
27、 these test conditions as follows: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 gravityvalue
28、s to two decimal places.10. 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 thr
29、ee materials were chosen from 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 (Tab
30、le 3).10.3 BiasA bias statement 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
31、 Labs1 23.1 0.70 0.712 18.6 1.21 0.913 13.1 1.37 0.33C1039 85 (2015)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 an
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34、ed a fair hearing you shouldmake 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
35、this standard may be obtained 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewoo
36、d Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 2 Precision of Bulk Density, Grams per Cubic CentimetreStandard 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 0.018C1039 85 (2015)3
