1、Designation: C 1179 91 (Reapproved 2005)An American National StandardStandard Test Method forOxidation Mass Loss of Manufactured Carbon and GraphiteMaterials in Air1This standard is issued under the fixed designation C 1179; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of revision, 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 provides a comparative oxidation massloss of m
3、anufactured carbon and graphite materials in air.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibil
4、ity 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. Summary of Test Method2.1 The test method determines mass loss characteristics ofcarbon and graphite articles in air as a function of temp
5、eratureand time by subjecting standard size specimens to mufflefurnace exposure and then comparing pre-test and post-testmass differentials.3. Significance and Use3.1 This test method is primarily concerned with the oxida-tion mass loss of manufactured carbon and graphite materialsin air at temperat
6、ures from 371 to 677C (700 to 1250F).3.2 The test method will provide acceptable results atpreselected test temperatures that yield less than 10 % massloss in 100 h. These results can be used to determine relativeservice temperatures.4. Interferences4.1 Results can be affected by materials released
7、by thefurnace walls or furniture. These materials may be present fromprevious oxidation test samples or other furnace use. It isrecommended that the furnace be operated at 1093C (2000F)for 1 h prior to use for oxidation mass loss testing.4.2 The validity of this test method depends upon theavailabil
8、ity of oxygen to the test specimen. The door of thefurnace shall be kept closed to maintain temperature control;however, the furnace door shall not be sealed, rendering thedoor airtight.4.3 Due to factors beyond the scope of the test method thatmight cause significant differences, this test method i
9、s onlyuseful for comparative results.5. Apparatus5.1 Muffle Furnace, with automatic temperature regulationwith 64C (67F) precision. Furnace chamber volume 983 to2458 cm3(60 to 150 in.3).NOTE 1Commercially available muffle furnaces advertised to achieve611C can be set up to achieve the necessary prec
10、ision.5.2 Thermocouple, K-type (chromel/alumel with Type 304stainless steel sheath).5.3 Digital Thermometer, for temperature readout.5.4 Crucible Tongs.5.5 Glazed Crucibles, flat bottom.25.6 Quart Glass Tray, or equivalent.5.7 Nylon Gloves, lint-free.5.8 Paper, lint-free.5.9 Analytical Balance, with
11、 0.001-g resolution.5.10 Desiccator, charged with indicating desiccant.6. Sample Preparation6.1 All specimens are to be handled with lint-free nylongloves or equivalent during all machining, handling, impreg-nation, and testing. Specimens should be kept free of contami-nation by placing them on clea
12、n nonmetallic surfaces during alloperations. Once the specimens have been oxidized, directhandling is not recommended.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.F0 on Manufactured Carbon an
13、d Graphite Products.Current edition approved June 1, 2005. Published August 2005. Originallyapproved in 1991. Last previous edition approved in 2000 as C 117991(2000).2The sole source of supply of the crucible (Coors crucible 60048) known to thecommittee at this time is Coors Ceramics Co., 17750 W.
14、32nd Ave., Golden, CO80401. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.1Copyright ASTM International, 100 Bar
15、r Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Test specimens are to consist of right cylinders 25.4-mmdiameter by 25.4 mm long 6 0.3 mm (1 in. by 1 in. 6 0.01 in.).Specimens are to be machined all over with carbide-tippedtools to achieve a surface roughness visuall
16、y comparable to32-in. arithmetic average (AA).6.3 Wipe specimens with lint-free paper to remove carbonmachining dust.6.4 Specimens and crucibles are to be clearly identified. Toavoid sample contamination, use a carbide-tipped scribe tomark the specimens. Crucibles can be marked with ceramicink.6.5 P
17、lace each specimen to be tested on its side (cylindricalsurface) in a dried, tared crucible. Specimens are to be kept inthe same crucible for the test duration. Record the individualidentification numbers for each specimen/crucible set.6.6 Dry the specimen/crucible sets in a vented oven at 120to 150
18、C (250 to 300F) for a minimum of 2 h. Remove thespecimen/crucible sets and cool in a desiccator for a minimumof 30 min to achieve room temperature.7. Procedure7.1 Before the running of this test method, the operatorshould practice the transferring of similar shaped specimensfrom furnace to desiccato
19、r. The specimen/crucible set shouldbe transferred so that the specimen is exposed to the atmo-sphere for no longer than 30 s. The desiccator should be in theimmediate vicinity of the furnace.7.2 Preheat and stabilize the furnace to the designated testtemperature as verified by a monitoring thermocou
20、ple extend-ing 50 mm (2 in.) into the chamber from the rear furnace wall(see Fig. 1).7.3 Just before testing, remove the specimen/crucible setsfrom the desiccator and immediately weigh on an analyticalbalance to the nearest 0.001 g. Record this data as pretest mass.7.4 Place two preweighed replicate
21、 specimen/crucible setson a quartz glass tray or equivalent and insert into the furnacechamber so that the monitoring thermocouple is approximatelycentered between the specimens. Specimens are to be 25 6 6mm (1 in. 6 0.24 in.) apart and centered on the monitoringthermocouple (see Fig. 1).7.5 Monitor
22、 the thermocouple reading and maintain furnacechamber temperature within 64C (67F) of the designatedtest temperature. Record the temperature readings from themonitoring thermocouple on the data sheet for the followingtimes for each test period:7.5.1 Just before inserting samples into furnace,7.5.2 1
23、 h after start, and7.5.3 Just before removing samples for weighing.7.6 Remove the specimen/crucible sets from the furnaceevery 25 61 h, for a total test time of 100 h, 615 min. Cool ina desiccator for a minimum of 30 min. Weigh the specimen/crucible set on an analytical balance to the nearest 0.001
24、g andrecord data as post-test mass for the specific test time intervalat the designated test temperature.7.7 Repeat 7.4 through 7.6 for 100 h total test duration.8. Calculation8.1 Calculate the percent mass loss after each time intervaland post test as follows:% mass loss 5 100 3F1 2SB 2 TA 2 TDGNOT
25、E 1A medium weight insulating firebrick has been found to be satisfactory for this purpose.NOTE 2Small wedges of ceramic (broken) crucible pieces can be used to hold samples in place.FIG. 1 Views of Furnace ChamberC 1179 91 (2005)2where:A = pre-test specimen/crucible set mass,B = post-test specimen/
26、crucible set mass, andT = crucible tare mass.9. Report9.1 Report the following information:9.1.1 Specimen identification, including material designa-tion and process lot number.9.1.2 Percent mass loss results for each specimen of 25, 50,75, and 100 h at designated test temperatures.10. Precision and
27、 Bias310.1 PrecisionThe precision of this test method wasdetermined via a round robin test among six laboratories. Twodifferent carbon materials were selected to verify the validity ofthe test method at lower and higher test temperatures. MaterialA, a carbon-graphite, was evaluated at 427C (800F) an
28、dMaterial B, an electrographite, was evaluated at 538C(1000F). All specimens of each material were from the sameprocessing lot, with six specimens of each material evaluatedby each laboratory. Evaluations were conducted in mufflefurnaces from various manufacturers with chamber volumesranging from 98
29、3 to 2458 cm3(60 to 150 in.3).10.2 The coefficient of variation for Material A within eachlaboratory was 0.1144 and between laboratories was 0.1140.For Material B, the coefficient of variation within each labo-ratory was 0.1804 and between laboratories was 0.4120.10.3 Testing was deliberately conduc
30、ted with different ma-terials to demonstrate capabilities of the test method for bothlower and higher temperatures. The data shows that morevariability exists at the higher test temperatures. At these morereactive temperature regimes, furnace differences, temperaturecontrol variations, and the avail
31、ability of oxygen must becarefully controlled to ensure consistent results.10.4 BiasNo statement on bias can be made because thetrue value of the oxidation mass loss has not been established.11. Keywords11.1 carbon; graphite; oxidation-airAPPENDIX(Nonmandatory Information)X1. OXIDATION TEST DATA SHE
32、ETX1.1 Fig. X1.1 is an example of a typical report sheet fortest data.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:C05-1009.C 1179 91 (2005)3ASTM International takes no position respecting the validity of any patent rights as
33、serted 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
34、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 rec
35、eive 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 Int
36、ernational, 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).FIG. X1.1 Sample Oxidation Test Data SheetC 1179 91 (2005)4
