1、Designation: C 1223 92 (Reappoved 2003)Standard 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,
2、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 This test method covers a procedure for causing theexudation of a glassy phase to the surface of fusion-c
3、astspecimens by subjecting 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 The values stated in inch-pound units are to be regardedas the stan
4、dard. The values given in parentheses are forinformation only.1.4 This standard does not 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
5、-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 20 Test Methods for Apparent Porosity, Water Absorp-tion, Apparent Specific Gravity, and Bulk Density ofBurned Refractory Brick and Shapes by Boiling Water3. Significance and Use3.1 This test method was devel
6、oped for use both by manu-facturers as a process control tool for the production of AZSfusion-cast refractories, and by glass manufacturers in theselection of refractories and design of glass-melting furnaces.3.2 The results may be considered as representative of thepotential for an AZS refractory (
7、specifically, in the testedregion) to contribute to glass defect formation during thefurnace production operation.3.3 The procedures and results may be applied to otherrefractory types or applications (that is, reheat furnace skidrailbrick) in which glass exudation is considered to be important.4. A
8、pparatus and Materials4.1 ScaleA laboratory scale rigged for suspension ofspecimens for dry/wet weight determinations to an accuracy of0.01 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 10
9、F (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 required 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 int
10、ended application (such asan arch block) in which exudation potential is of interest.5. Test Specimens and Sampling5.1 Specimens may 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
11、 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 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 specif
12、ied, with minimalspecimen-to-specimen variation. Excessive thickness can pre-vent isothermal heating within the specimen. Height and 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 pr
13、oduct should be made relative toonly the intended application. For example, a convenientlysized bottom paver might not be representative of a largersuperstructure casting because (for example) casting moldtypes and solidification rates may have been different duringmanufacture.1This test method is u
14、nder the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.10 on Refrac-tories for Glass.Current edition approved November 1, 2003. Published January 2004. Originallypublished in 1992. Last previous edition approved in 1998 as C 122392 (1998).2For
15、 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, 100 Barr Harbor Drive, PO Box C700
16、, West Conshohocken, PA 19428-2959, United States.5.4 The location and depth of specimens within the originalcasting can influence the results. Regions closely underlyingthe surface of the casting (particularly near the corners andedges) are thermally quenched and have aligned microstruc-tures that
17、are atypical of more slowly cooled regions. Deeper ina casting, glass phase pockets and crystal sizes are larger, andcertain shifts in chemical stratification exist due to fractionalcrystallization during solidification. No single point in an AZScasting represents the whole entirely.5.5 Regular-cast
18、 AZS blocks, approximately 8 to 12-in.(203 to 305-mm) thick, such as is typical of furnace super-structure and sidewall sizes, are sampled 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) sh
19、ould 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; then break out fromthe casting and saw square to 4-in. (102-mm) length, retainingthe moldskin (original surface of the block) on one end of thespecimen by cutting
20、off the end opposite it.5.5.3 The quantity of specimens per casting is not specified.(Correlation coefficients of 10 to 20 % 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
21、 and location are determined by originalcasting size. That is, the proximity of specimen location to anyedge should be no less than half the casting thickness. Thespecimen length should be approximately half the castingthickness.5.7 Solid-cast tile (3 in. (76 mm) should be sampledperpendicularly to
22、a major face, with the proximity to any edgebeing no less than half the thickness of the casting. Thespecimen length should 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,
23、 may besampled perpendicularly to any of the four major verticalsurfaces, with the following restrictions: sampling should 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
24、top“metal-line” region, as when the casting is inverted, has beenfound to be not representative of the overall casting.6. Procedure6.1 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 fo
25、il willusually be fused together at the end of testing and cannot beseparated before weighing without risk of lost exudate. Oncepaired, 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 surfa
26、ce-connected porosity in specimen cores, the treatments (dryingFIG. 1 WorksheetRound Robin No. 2 for AZS ExudationC 1223 92 (Reappoved 2003)2and boiling) as specified by Test Methods C 20 must beapplied, as described as follows:6.3 Dry the specimen cores to constant weight by heating to220 to 230F (
27、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 no contact with the heated bottom of thecontainer.6.5 After the boiling period, cool the te
28、st 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 suspended in water, tothe nearest 0.01 g.6.7 This weighing is usually accomplished by suspendi
29、ngthe 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 counter-balanced previ-ously with the wire in place and immersed in water to the samedepth as is used when the refractory specimens are in pla
30、ce.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 testfurnace with the sawed ends facing downward. Form the foilinto crude cups so that any rundown of exuda
31、tion 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 temperature for 4 h.6.11.3 Shut the power off; let the furnace coil.6.11.4 Remove the specimen cores w
32、ith 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 exudation.6.12 Prepare the specimen cores (with foil attached) for wetweighing by first boiling again a
33、s described in 6.4 and 6.5.Care should be taken to avoid turbulent boiling, which mightcause fracture and loss of exudate.6.13 Determine the specimen core-plus-foil wet weight(Ww2) after boiling, and while suspended in water, to thenearest 0.01 g.6.14 Dry the specimen core-plus-foil to constant weig
34、ht byheating to 220 to 230F (105 to 110C), and determine the dryweight (Wd2) to the nearest 0.01 g.NOTE 2The drying of specimens to constant weight can be avoided asa procedural step if specimens are weighed (Wd2) shortly after beingremoved from the test furnace.7. Calculation7.1 Exudate is defined
35、as the percent increase in originalvolume of the specimen core.7.2 Calculations are simplified by first converting dry versuswet weight differences into volumes, and by correcting for theweight of attached foil, as follows:volume15 Wd12 Ww1! 5 _ cc (1)exuded core dry weight ECDW!5Wd22 PWd1!5 _ g (2)
36、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 to the extent of beading or rundown ofexudate on the specimen.7.5 Gain or loss of specimen dr
37、y 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 additionalexudation considerably above a level that the increased
38、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 relativelypoor performances of intermittently operated glass mel
39、tingfurnace.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 shouldbe relative to the original (untested) volume.9. Adj
40、ustments9.1 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)hysteresis and high-temperature creep, are known to have aneffect on volume, albeit minor compared to that of exudatio
41、n.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 randomized set of four cores.Each laboratory tested the specimen cores for c
42、umulativeexudation over three temperature cycles (see Section 8).10.2 PrecisionPrecision and relative precision data at the95 % confidence level are given in Table 1.10.3 BiasNo justifiable statement on bias can be madesince the true value cannot be established from an acceptedreference sample.C 122
43、3 92 (Reappoved 2003)311. Keywords11.1 AZS; casting; exudation; fusion-cast; glass (glassphase); refractoriesASTM 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
44、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 reviewed every five years andif not revised, either reap
45、proved 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 theresponsible technical committee, which you may attend. If you
46、 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 Conshohocken, PA 19428-2959,United States. Individual
47、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).TABLE 1 Precision StatisticsPrecision Cycle 1 Cycle 2Average, x 2.98 8.7
48、3Standard 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 92 (Reappoved 2003)4
