1、Designation: C987 10Standard Test Method forVapor Attack on Refractories for Furnace Superstructures1This standard is issued under the fixed designation C987; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. 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 a procedure for comparing thebehavior of refractories in contact with vapors under conditionsintended to s
3、imulate the environment within a glass melting orother type of furnace when refractories are exposed to vaporsfrom raw batch, molten glass, fuel, fuel contaminants, or othersources. This procedure is intended to accelerate serviceconditions for the purpose of determining in a relatively shorttime th
4、e interval resistance to fluxing, bloating, shrinkage,expansion, mineral conversion, disintegration, or other physi-cal changes that may occur.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 purpor
5、t 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. Significance and Use2.1 This test method prov
6、ides a guide for evaluating theresistance of refractories in glass melting furnace superstruc-tures to vapor attack. This test method may also be useful forevaluating refractories in other applications where vapor attackoccurs.2.2 An electric-heated furnace is recommended. Water va-por and other atm
7、ospheric components in a gas- or fuel-firedfurnace may participate in the chemical and physical reactionsbeing studied. Results may differ, therefore, depending uponthe nature and type of firing employed.2.3 The degree of correlation between this test method andservice performance is not fully deter
8、minable. This is intendedto be an accelerated test method that generates a substantialdegree of reaction in a relatively short amount of time. Thisacceleration may be accomplished by changing the composi-tion and/or concentration of the reactants, increasing tempera-tures, or by performing the test
9、in an isothermal environment.2.4 Since the test method may not accurately simulate theservice environment, observed results of this test method maynot be representative of those found in service. It is imperativethat the user understand and consider how the results of thistest method may differ from
10、 those encountered in service. Thisis particularly likely if the reaction products, their nature, ortheir degree differ from those normally found in the actualservice environment.2.5 It is incumbent upon the user to understand that this isan aggressive, accelerated test method and to be careful inin
11、terpreting the results. If, for example, the reaction specieshave never been found in a real world furnace, then this testmethod should not necessarily be considered valid to evaluatethe refractory in question.3. Apparatus3.1 The crucible for containing the reactant shall be a densealumina or platin
12、um crucible of conical shape with dimensionsof 43 mm in diameter at top, 33 mm in diameter at bottom, and53 mm high.3.2 The crucible-cover assembly (Fig. 1) may be supportedwithin a suitable refractory holding crucible (Fig. 2) such asmullite to maintain the position of the cover, if an excessiveamo
13、unt of glass phase reaction product is anticipated.3.3 The electric heating chamber shall be of sufficient sizeto accommodate at least three assemblies for comparativeevaluation. The temperature control system shall be capable ofmaintaining a desired holding temperature with a tolerance of63C.4. Spe
14、cimen Preparation4.1 The test specimen shall conform to the followingdimensions with major faces cut or ground parallel and flat toform a tight seal with top of crucible:4.1.1 Length, 55 6 2 mm,4.1.2 Width, 55 6 2 mm, and4.1.3 Thickness, 20 6 1.0 mm.4.2 SelectionUse specimens that are free of defect
15、s suchas cracks, fissures, and voids. Where obvious defects inspecimens appear after testing is completed, disregard theresults and repeat the test.1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.10 on Refractories
16、for Glass.Current edition approved Sept. 1, 2010. Published October 2010. Originallyapproved in 1983. Last previous edition approved in 2005 as C987 00a (2005).DOI: 10.1520/C0987-10.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3
17、 Three specimens of a refractory brand shall constitute atest.5. Procedure5.1 The reactant shall be selected such that the vaporgenerated during the test is similar to the vapor encountered inservice. Some reactants that have been found suitable for thispurpose are: carbonates, sulphates, borates, a
18、nd halides.5.2 For comparative evaluations, a consistent weight ofreactant is to be used. The level of the reactant is not to exceed40 % of the depth of the crucible in order to avoid contactbetween the molten reactant and the specimen. An example ofa suitable quantity of reactant is 12.5 g of techn
19、ical gradesodium carbonate.5.2.1 Use molar equivalents for alternative reactants provid-ing that the level of this reactant does not exceed 40 % of thecrucible depth.5.2.2 The test temperature shall be appropriate to thereactant and the environment to be simulated. For example, atemperature of 1370C
20、 has been found to give measurableresults when using a sodium carbonate reactant.5.3 Place a weighed amount of reactant in a crucible.5.4 Assemble the crucible and the specimen, and place it ona level furnace hearth. An assembly having a test specimenwith a silica content greater than 50 % should be
21、 placed in aholding crucible to prevent disorientation by glass phasedevelopment (see Fig. 2).5.5 A consistent heating rate of 2 to8htotest temperatureand a duration of 24 h at temperature shall constitute the test.Allow the crucible assembly to cool in a manner that preventsthermal shock.5.6 Separa
22、te the sample from the reactant crucible aftercooling.6. Report6.1 Report the following information:6.1.1 Materials tested,6.1.2 Test temperature,6.1.3 Type and quantity of reactant(s), and6.1.4 Observations as to the condition of the specimens aftertesting. It may be desirable to cut the specimens
23、in half andexpose a cross-sectional view.6.1.4.1 These observations may be, but are not limited to:photographs, written comments, change of weight of speci-mens, change of dimensions of specimens, change of flatnessof specimens, change of mineralogy, and development ofcracks in specimens.7. Precisio
24、n and Bias7.1 PrecisionNo justifiable statement of precision is pos-sible since the results of this test method are word descriptionsrather than numerical values.7.2 BiasNo justifiable statement of bias is possible sincea true value of refractory attack by vapor cannot be establishedby an accepted r
25、eference sample.8. Keywords8.1 corrosion; glass; refractories; superstructures; vaporattackFIG. 1 Crucible-Cover AssemblyFIG. 2 Refractory Holding CrucibleC987 102ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this s
26、tandard. 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 time by the responsible technical committee and must be re
27、viewed 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 receive careful consideration at a meeting of therespons
28、ible 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 International, 100 Barr Harbor Drive, PO Box C700, West
29、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 through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).C987 103
