1、Designation: C 1223 09Standard Test Method forTesting of Glass Exudation from AZS Fusion-CastRefractories1This standard is issued under the fixed designation C 1223; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、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 a procedure for causing theexudation of a glassy phase to the surface of fusion-castspecimens by su
3、bjecting them to temperatures correspondingto glass furnace operating temperatures.1.2 This test method covers a procedure for measuring theexudate as the percent of volume increase of the specimen aftercooling.1.3 UnitsThe values stated in inch-pound units are to beregarded as standard. The values
4、given in parentheses aremathematical conversions to SI units that are provided forinformation only and are not considered standard.1.3.1 ExceptionThe balance required for this test methoduses only SI units (Section 6).1.4 This standard does not purport to address all of thesafety concerns, if any, a
5、ssociated 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 Standards:2C20 Test Methods for Apparent Porosity, Water Absorp-t
6、ion, Apparent Specific Gravity, and Bulk Density ofBurned Refractory Brick and Shapes by Boiling Water3. Significance and Use3.1 This test method was developed for use both by manu-facturers as a process control tool for the production of AZSfusion-cast refractories, and by glass manufacturers in th
7、eselection of refractories and design of glass-melting furnaces.3.2 The results may be considered as representative of thepotential for an AZS refractory (specifically, in the testedregion) to contribute to glass defect formation during thefurnace production operation.3.3 The procedures and results
8、may be applied to otherrefractory types or applications (that is, reheat furnace skid railbrick) in which glass exudation is considered to be important.4. Apparatus and Materials4.1 ScaleA laboratory scale or balance rigged for suspen-sion of specimens for dry/wet weight determinations to anaccuracy
9、 of 0.01 g.4.2 KilnAn electric kiln to accommodate several 4-in.(102-mm) specimen cores placed vertically on end, and forservice at 2750F (1510C), with a variation of 10F (6C).4.3 FoilCups formed from 214-in. (56-mm) squares ofplatinum foil (Pt, 5 % Au alloy, 0.003-in. (0.076-mm) thick).One cup requ
10、ired per specimen.4.4 AZS CastingA virgin casting having no prior thermalhistory except that of its own formation, and of a size andcasting process equivalent to the intended application (such asan arch block) in which exudation potential is of interest.5. Test Specimens and Sampling5.1 Specimens ma
11、y be removed from the original castingeither as drilled cores or as sawed bars, depending on labora-tory capability. Specimen cores or bars should be 4-in. (102-mm) long and either 1 in. (25.4 mm) in diameter or 1 by 1 in.(25.4 by 25.4 mm) in cross-section. The length dimension ofthe specimen should
12、 be perpendicular to the surface of theblock from which it is removed.5.2 The dimensions of the prepared specimen core are notcritical but should be maintained as specified, with minimalspecimen-to-specimen variation. Excessive thickness can pre-vent isothermal heating within the specimen. Height an
13、d widthcan affect the positioned stability of the specimen in the kilnduring heating.5.3 The size of the original casting may influence theresults. Evaluations of the product should be made relative toonly the intended application. For example, a convenientlysized bottom paver might not be represent
14、ative of a larger1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.10 on Refrac-tories for Glass.Current edition approved March 1, 2009. Published April 2009. Originallyapproved in 1992. Last previous edition approve
15、d in 2003 as C 122392 (2003).2For referenced ASTM standards, visit the ASTM website, 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.1Copyright ASTM International, 1
16、00 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.superstructure casting because (for example) casting moldtypes and solidification rates may have been different duringmanufacture.5.4 The location and depth of specimens within the originalcasting can influence the re
17、sults. Regions closely underlyingthe surface of the casting (particularly near the corners andedges) are thermally quenched and have aligned microstruc-tures that are atypical of more slowly cooled regions. Deeper ina casting, glass phase pockets and crystal sizes are larger, andcertain shifts in ch
18、emical stratification exist due to fractionalcrystallization during solidification. No single point in an AZScasting represents the whole entirely.5.5 Regular-cast AZS blocks, approximately 8 to 12-in.(203 to 305-mm) thick, such as is typical of furnace super-structure and sidewall sizes, are sample
19、d by drilling or plunge-cutting perpendicularly to the bottom surface (the surfaceopposite the casting scar).5.5.1 The location of entry (by drilling or sawing) should beat least 4-in. (102-mm) away from any edge, yet not immedi-ately under the casting scar.5.5.2 Drill or cut deeper than specified;
20、then break thespecimen out from the casting and saw square to 4-in.(102-mm) length, retaining the mold skin (original surface ofthe block) on one end of the specimen by cutting off the endopposite it.5.5.3 The quantity of specimens per casting is not specified.(Correlation coefficients of 10 to 20 %
21、 have been obtained bythis procedure on large specimen populations taken from singlecastings.)5.6 For smaller regular-cast blocks less than 8-in. (203-mm)thick, specimen length and location are determined by theoriginal casting size. That is, the proximity of specimenlocation to any edge should be n
22、o less than half the castingthickness. The specimen length should be approximately halfthe casting thickness.5.7 Solid-cast tile (3 in. (76 mm) should be sampledperpendicularly to a major face, with the proximity to any edgebeing no less than half the thickness of the casting. Thespecimen length sho
23、uld be either half the thickness or fullsurface-to-surface thickness.5.8 Large, vertically-cast blocks, such as those that are usedcommonly in high-wear glass-contact applications, may besampled perpendicularly to any of the four major verticalsurfaces, with the following restrictions: sampling shou
24、ld be atleast 4 in. (102 mm) from any edge, and the entire bottomregion should be avoided up to 8 in. (203 mm) from the bottom(as-cast). This lower region, which often becomes the top“metal-line” when the casting is inverted, has been found to benot representative of the overall casting.6. Procedure
25、6.1 Weights must be obtained individually for both theuntested specimen cores and the foil squares on which thecores will be placed. This is because each core and its foil willusually be fused together at the end of testing and cannot beseparated before weighing without risk of lost exudate. Oncepai
26、red, each set of core-and-foil must remain together through-out testing and subsequent calculation of data (see Fig. 1).6.2 To account for the possible presence of surface-connected porosity in specimen cores, the treatments (dryingand boiling) as specified by Test Methods C20 must beapplied, as des
27、cribed as follows:6.3 Dry the specimen cores to constant weight by heating to220 to 230F (105 to 110C), and determine the dry weight(Wd1) to the nearest 0.01 g.6.4 Place the specimen cores in water and boil for 2 h. Keepthe specimens entirely covered with water during the boilingperiod, and permit n
28、o contact with the heated bottom of thecontainer.6.5 After the boiling period, cool the test specimens to roomtemperature while still covered completely with water, for aminimum of 12 h before weighing.6.6 Determine the specimen core wet weight (Ww1) of eachspecimen core after boiling and while susp
29、ended in water, tothe nearest 0.01 g.6.7 This weighing is usually accomplished by suspendingthe specimen in a loop or halter of copper wire (such as AWGGage 22, 0.643 mm) hung from one arm, or from the undersideof the balance. The balance shall be tared or counter-balancedpreviously with the wire in
30、 place and immersed in water to thesame depth as is used when the refractory specimens are inplace.6.8 Determine the platinum foil dry weight (PWd1)tothenearest 0.01 g.6.9 Determine the platinum foil wet weight (PWw1)tothenearest 0.01 g.6.10 Stand the specimen cores on foil squares in the testfurnac
31、e with the sawed ends facing downward. Form the foilinto crude cups so that any rundown of exudation will becontained. Failure to use foil may result in disappearance ofexudate into the furnace floor.6.11 Heating Cycle:6.11.1 Over 12 h, attain 2750F 6 10F (1510C 6 6C).6.11.2 Maintain the test temper
32、ature for 4 h.6.11.3 Shut the power off; let the furnace coil.6.11.4 Remove the specimen cores with adhered foil; allowto cool for 24 h.NOTE 1A stable, uninterrupted test temperature is essential; it hasbeen found that cooling and reheating of AZS specimens can cause asignificant increase in exudati
33、on.6.12 Determine the dry weight of the specimen with the foilattached (Wd2) to the nearest 0.01 g.6.13 Prepare the specimen cores (with foil attached) for wetweighing by first boiling again as described in 6.4 and 6.5.Care should be taken to avoid turbulent boiling, which mightcause fracture and lo
34、ss of exudate.6.14 Determine the specimen core-plus-foil wet weight(Ww2) after boiling, and while suspended in water, to thenearest 0.01 g.NOTE 2Alternately, the weight (Wd2) of the specimen core plus foilcan be determined after wet weighing by drying to constant weight at 220to 230F (105 to 110C).7
35、. Calculations and Reporting7.1 Exudate is defined as the percent increase in originalvolume of the specimen core.C 1223 0927.2 Calculations are simplified by first converting dry versuswet weight differences into volumes, and by correcting for theweight of attached foil, as follows:volume15 Wd12 Ww
36、1! 5 _ cc (1)exuded core dry weight ECDW!5Wd22 PWd1!5 _ g (2)exuded core wet weight ECWW!5Ww22 PWw1!5 _ g (3)volume25 ECDW 2 ECWW 5 _ cc (4)7.3 Thus,% exudation 5volume22 volume1volume13 100 7.4 Observations may be made concerning the clarity andcolor of exudate, and the extent of beading or rundown
37、 ofexudate on the specimen.7.5 Gain or loss of specimen dry weight after testing may benoted as a check upon the accidental loss of exudate.8. Retesting (Cycling) for Additional Exudation8.1 Prior work has shown that the reheating (temperaturecycling) of oxidized AZS specimen cores produces addition
38、alexudation considerably above a level that the increased time-at-temperature could explain. Reheating has been found tohave more effect on total exudation than the variables of time,temperature, casting size, or specimen location. This phenom-enon may have application in understanding of the relati
39、velypoor performances of intermittently operated glass meltingfurnace.8.2 To obtain a measure of reheat exudation, repeat testingtwo more times on the same specimens, starting each time atroom temperature. Calculate the incremental and cumulativevolume increases after each test. Changes as measured
40、shouldbe relative to the original (untested) volume.9. Adjustments9.1 It is acknowledged that the volume changes in AZSspecimens that occur during heating are not entirely the resultof exudation. Other variables, such as the zirconia (ZrO2)expansion hysteresis and high-temperature creep, are known t
41、ohave an effect on volume, albeit minor compared to that ofexudation.10. Precision and Bias10.1 Interlaboratory DataAn interlaboratory study wasconducted in 1991 in which specimen cores drilled from asingle AZS (33 % ZrO2) casting were tested for exudation.Five laboratories each received a randomize
42、d set of four cores.Each laboratory tested the specimen cores for cumulativeexudation over three temperature cycles (see Section 8).10.2 PrecisionPrecision and relative precision data at the95 % confidence level are given in Table 1.FIG. 1 WorksheetRound Robin No. 2 for AZS ExudationC 1223 09310.3 B
43、iasNo justifiable statement on bias can be madesince the true value cannot be established from an acceptedreference sample.11. Keywords11.1 AZS; casting; exudation; fusion-cast; glass (glassphase); refractoriesASTM International takes no position respecting the validity of any patent rights asserted
44、 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 time by the
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46、areful 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 Internati
47、onal, 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 through th
48、e ASTM website(www.astm.org).TABLE 1 Precision StatisticsPrecision Cycle 1 Cycle 2Average, x 2.98 8.73Standard within, Sr0.376 0.816Deviation between, SR0.706 0.841Repeatability interval, r 1.05 2.29Reproducibility interval, R 1.98 2.35Relative PrecisionCoefficient of variation:within laboratory, Vr12.6 9.35between laboratories, VR23.7 9.63Relative repeatability, % r 35.3 26.2Relative reproducibility, % R 66.3 26.9C 1223 094
