1、Designation: C 454 83 (Reapproved 2007)Standard Practice forDisintegration of Carbon Refractories by Alkali1This standard is issued under the fixed designation C 454; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice shows the behavior of carbon refractorieswhen subjected to the action of an alkali at an elevatedtemperatur
3、e. This destructive condition as encountered inservice is accelerated in the test to show in a short time theprobable behavior of the carbon refractory during use.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are providedfor information
4、only.1.3 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-bility of regulatory limitations prior to use.2. Signifi
5、cance and Use2.1 The disintegration of carbon refractories by alkali attackat elevated temperatures is an important consideration in usingthese materials for certain applications. Disruption of carbonrefractories in the test is sensitive to a number of variables,including alkali concentration, tempe
6、rature, and the presenceof water vapor. The procedure is suitable for guidance inproduct development and for relative comparisons in applica-tion work such as in blast furnace service.3. Apparatus and Materials3.1 Sagger A sagger, and coke breeze passing a No. 4(4.75-mm) sieve.3.2 KilnThe kiln shall
7、 be capable of maintaining thespecified rate of heating. During the temperature holdingperiod, the temperature distribution over the hearth shall notvary more than 615F (8C).3.3 Potassium Carbonate (K2CO3)Anhydrous granular.4. Test Specimens4.1 Ten specimens constitute a specimen set and not moretha
8、n one specimen is taken from a given carbon shape.4.2 Two-inch (51-mm) cube specimens are cut from theshapes to a manner so as to maintain as many of the originalsurfaces as possible.4.3 A hole78 in. (22 mm) in diameter and 1 in. (25 mm)deep is drilled into the center of one face of each specimen.4.
9、4 Cut a lid from a carbon shape measuring approximately2by2by14 in. (50 by 50 by 6 mm) for each specimen.5. Procedure5.1 Dry the specimens and lids at 220 to 230F (105 to110C) for at least 1 h. Place8gofK2CO3in the hole of eachspecimen, and then place a lid over each hole.5.2 Place the prepared spec
10、imens in the sagger, using cokebreeze as a packing material to prevent oxidation. Maintain adistance of not less than 1 in. (25 mm) between the inner wallof the sagger and any specimen, and not less than14 in. (6mm) between specimens. Cover the uppermost specimen witha layer of coke breeze at least
11、1 in. in thickness and place aclose-fitting cover on the sagger. The lid may be sealed in placearound the outside of the sagger by the use of air-settingrefractory mortar.5.3 Heat the sagger assembly in the kiln at a rate notexceeding 360F (200C)/h until 1750F (955C) is reached;maintain that tempera
12、ture within 615F (8.5C) for 5 h.5.4 During the cooling period, remove the specimens fromthe sagger before they reach 210F (100C) and store, untilexamined and photographed, in a desiccator or drying ovenoperating at 220 to 230F (105 to 110C).NOTE 1If there is a delay between preparing (5.1) and heati
13、ng (5.3)the specimens, store them or the sagger-specimen assemblage in adesiccator or in an oven maintained at 220 to 230F (105 to 110C) untilthe procedure is continued.6. Report6.1 Report the condition of each test specimen upon beingremoved from the sagger, and attach a photograph to thewritten re
14、port. The photograph shall show the top and two sidesof each specimen at not less than half their actual size.6.2 Use the following classification in reporting the condi-tion of the specimens:6.2.1 Unaffected (U), no visible cracks,6.2.2 Lightly Cracked (LC), hairline cracks,6.2.3 Cracked (C), crack
15、s greater than164 in. (0.4 mm)wide, or6.2.4 Disintegrated (D), broken into two or more pieces.6.3 Type of heat source, kiln, and muffling.1This practice is under the jurisdiction ofASTM Committee C08 on Refractoriesand is the direct responsibility of Subcommittee C08.04 on Chemical Behaviors.Current
16、 edition approved March 1, 2007. Published April 2007. Originallyapproved in 1960. Last previous edition approved in 2002 as C 454 83 (2002).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Precision and Bias7.1 Precision No justif
17、iable statement on precision can bemade since the results of the test are reported by descriptionsand photographs, and the degree of variability cannot beestablished.7.2 BiasNo justifiable statement on bias can be madesince the true or standard value for the degree of disintegrationcannot be establi
18、shed by an accepted reference method.8. Keywords8.1 alkali; carbon refractories; disintegrationASTM 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 determina
19、tion 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 reapproved or with
20、drawn. 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 feel that you
21、r 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 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).C 454 83 (2007)2
