1、Designation: C863 00 (Reapproved 2016)Standard Test Method forEvaluating Oxidation Resistance of Silicon CarbideRefractories at Elevated Temperatures1This standard is issued under the fixed designation C863; the number immediately following the designation indicates the year oforiginal adoption or,
2、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 This test method covers the evaluation of the oxidationresistance of silicon carb
3、ide refractories at elevated tempera-tures in an atmosphere of steam. The steam is used toaccelerate the test. Oxidation resistance is the ability of thesilicon carbide (SiC) in the refractory to resist conversion tosilicon dioxide (SiO2) and its attendant crystalline growth.1.2 This standard does n
4、ot purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of 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 Standar
5、ds:2C20 Test Methods for Apparent Porosity, Water Absorption,Apparent Specific Gravity, and Bulk Density of BurnedRefractory Brick and Shapes by Boiling WaterC830 Test Methods for Apparent Porosity, LiquidAbsorption, Apparent Specific Gravity, and Bulk Densityof Refractory Shapes by Vacuum PressureC
6、914 Test Method for Bulk Density and Volume of SolidRefractories by Wax Immersion3. Significance and Use3.1 The oxidation of silicon carbide refractories at elevatedtemperatures is an important consideration in the application ofthese refractories. The product of oxidation is amorphous silicaor cris
7、tobalite, depending upon the temperature at whichoxidation takes place. This oxide formation is associated withexpansion and degradation of strength. The quantity of watervapor in the atmosphere greatly affects the rate of oxidation.3.2 The test, which creates and measures the expansion, issuitable
8、for guidance in product development and relativecomparison in application work where oxidation potential is ofconcern. The variability of the test is such that it is notrecommended for use as a referee test.4. Apparatus4.1 Heated ChamberThe chamber shall be muffled (Note1) to confine the atmosphere.
9、 The size of the chamber and theheat source are optional. The temperature capability within thechamber shall be at least 1200C (2190F) with an allowabledeviation of 615C (27F) measured across the hearth.NOTE 1Silicon carbide refractory material is recommended for use asthe muffle but other suitable
10、refractory materials may be used.4.2 InstrumentControl and record the temperature of thechamber by a suitable instrument capable of maintaining therequirements in 4.1. Recommended thermocouple location iswithin 1 in. (25 mm) of the top of the specimens and over thecenter of the same assemblage.5. Te
11、st Specimen5.1 Specimen SizeObtain a quarter-brick size from a229-mm (9-in.) straight by cutting the brick along planesparallel to both the 229 by 64-mm (9 by 212-in.) and the 114 by64-mm (412 by 212-in.) faces. Alternative specimens may betile, 165 by 114 by 22 mm (612 by 412 by78 in.), or othercon
12、venient shapes.5.2 Three specimens are required for each set of conditions.6. Conditions6.1 AtmosphereSteam is passed into the chamber (4.1)atthe rate of 32 kg/m3(2 lb/ft3) of chamber volume per hour.Provisions should be made to uniformly distribute steam withinthe chamber.6.2 The standard test temp
13、eratures are as follows with newsamples used at each temperature. Each temperature consti-tutes a test.800C (1470F)900C (1650F)1000C (1830F)1100C (2010F)1200C (2190F)1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.
14、04 on ChemicalBehaviors.Current edition approved June 1, 2016. Published June 2016. Originallyapproved in 1977. Last previous edition approved in 2010 as C863 00 (2010).DOI: 10.1520/C0863-00R16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at s
15、erviceastm.org. For Annual Book of ASTMStandards volume 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 States1The test temperature is selected on the basis of the
16、specificneeds that relate to the environment in which the product is toserve. The use of at least the three test temperatures 900C,1000C, and 1100C is recommended when characterization ofthe product is desired.6.3 DurationHold at the specified temperature for 500 h.7. Procedure7.1 Measure the weight
17、 and volume of each specimen to60.1 g and 60.1 cm3, respectively, in accordance with TestMethods C20, C830,orC914, especially recommended forfriable samples.7.2 Place the specimens in the chamber and seal thechamber. Bring the chamber to the specified test temperatureand then introduce steam at the
18、prescribed rate (6.1).7.3 Upon completion of the 500-h period at the prescribedtemperature, shut off the steam supply and then the heat source.When specimens are cool, measure the weight and volumeusing the same method used for 7.1, and calculate the bulkdensity.8. Report8.1 The average percent volu
19、me change based on theoriginal volume is reported as the prime variable with weight,bulk density, and length changes included as supplementaryinformation. The percent volume change equals 100 times thedifference between the new and original volume all divided bythe original volume, orVolume Change,
20、% 5Vn2 Vo!Vo3100where:Vn= new volume andVo= original volume.9. Precision and Bias9.1 Interlaboratory Test Data and AnalysisThree speci-mens each of five different materials were tested by fivelaboratories. The test data and analyses used in establishingthis precision statement are filed as a round r
21、obin.3Thevariable measured is percent volume expansion, the testtemperature 1100C (2010F).9.2 PrecisionTwo averages of observed values should beconsidered significantly different at the 95 % probability levelif the difference equals or exceeds the critical differences listedin Table 1.9.3 BiasNo jus
22、tifiable statement on bias can be madesince the true or standard value of volume expansion for thesematerials cannot be established by an accepted referencemethod.10. Keywords10.1 oxidation; refractories; silicon carbideASTM International takes no position respecting the validity of any patent right
23、s 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 the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any t
24、ime 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 of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will
25、 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 shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM
26、 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 obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or
27、through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ data have been filed at ASTM International Headquarters and maybe obtained by requesting Rese
28、arch Report RR:C08-1004.TABLE 1 Example of Critical Difference ValuesANumber of Ob-servations inEach AverageCritical Difference BetweenAverages, Units of MeasureSingle-OperatorBetween-LaboratoryFrit Bonded SiC 3 3.26 18.11Clay Bonded SiC 3 32.13 31.34Fines Bonded SiC 3 0.39 0.81Silicon OxynitrideBonded SiC 3 1.91 7.25Silicon NitrideBonded SiC 3 0.27 0.56AThis table is excerpted from RR:C08-1004, available from ASTM Headquarters.C863 00 (2016)2
