ASTM C1179-1991(2010)e1 Standard Test Method for Oxidation Mass Loss of Manufactured Carbon and Graphite Materials in Air《室外加工碳素材料及石墨材料氧化质量损失的标准试验方法》.pdf

1、Designation: C1179 91 (Reapproved 2010)1An American National StandardStandard Test Method forOxidation Mass Loss of Manufactured Carbon and GraphiteMaterials in Air1This standard is issued under the fixed designation C1179; the number immediately following the designation indicates the year oforigin

2、al adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEUpdated units of measurement throughout the standard editorially in May

3、2010.1. Scope1.1 This test method provides a comparative oxidation massloss of manufactured carbon and graphite materials in air.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 purport to address a

4、ll 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. Summary of Test Method2.1 The test method determines mass l

5、oss characteristics ofcarbon and graphite articles in air as a function of temperatureand 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

6、-tion mass loss of manufactured carbon and graphite materialsin air at temperatures from 371 to 677C.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.

7、 Interferences4.1 Results can be affected by materials released 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 for 1 hprior to use for oxidation mass loss testing.4.2 Th

8、e validity of this test method depends upon theavailability 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 tha

9、tmight cause significant differences, this test method is onlyuseful for comparative results.5. Apparatus5.1 Muffle Furnace, with automatic temperature regulationwith 64C precision. Furnace chamber volume 983 to 2458cm3.NOTE 1Commercially available muffle furnaces advertised to achieve611C can be se

10、t up to achieve the necessary precision.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

11、-free.5.9 Analytical Balance, with 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 cont

12、ami-nation by placing them on clean nonmetallic surfaces during alloperations. Once the specimens have been oxidized, directhandling is not recommended.6.2 Test specimens are to consist of right cylinders 25.4-mmdiameter by 25.4 mm long 6 0.3 mm. Specimens are to be1This test method is under the jur

13、isdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.F0 on Manufactured Carbon and Graphite Products.Current edition approved May 1, 2010. Published May 2010. Originallyapproved in 1991. Last previous edition approved in 2005 as C117

14、9 91 (2005).DOI: 10.1520/C1179-91R10E01.2The sole source of supply of the crucible (Coors crucible 60048) known to thecommittee at this time is Coors Ceramics Co., 17750 W. 32nd Ave., Golden, CO80401. If you are aware of alternative suppliers, please provide this information toASTM International Hea

15、dquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.machined all over with carbide-tipped tools to ach

16、ieve asurface roughness visually comparable to 0.8-m. arithmeticaverage (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

17、be marked with ceramicink.6.5 Place 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 set

18、s in a vented oven at 120to 150C for a minimum of 2 h. Remove the specimen/cruciblesets and cool in a desiccator for a minimum of 30 min toachieve room temperature.7. Procedure7.1 Before the running of this test method, the operatorshould practice the transferring of similar shaped specimensfrom fur

19、nace to desiccator. 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 mon

20、itoring thermocouple extend-ing 50 mm into the chamber from the rear furnace wall (seeFig. 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

21、replicate 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 apart and centered on the monitoring thermocouple (seeFig. 1).7.5 Monitor the therm

22、ocouple reading and maintain furnacechamber temperature within 64C of the designated testtemperature. Record the temperature readings from the moni-toring thermocouple on the data sheet for the following timesfor each test period:7.5.1 Just before inserting samples into furnace,7.5.2 1 h after start

23、, 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 g andrecord da

24、ta 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 TDGNOTE 1A medium we

25、ight 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 ChamberC1179 91 (2010)12where:A = pre-test specimen/crucible set mass,B = post-test specimen/crucible set m

26、ass, 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 Bias310.1 Pre

27、cisionThe 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 and Material B,an elect

28、rographite, was evaluated at 538C. All specimens ofeach material were from the same processing lot, with sixspecimens of each material evaluated by each laboratory.Evaluations were conducted in muffle furnaces from variousmanufacturers with chamber volumes ranging from 983 to2458 cm3.10.2 The coeffi

29、cient 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 conducted with different ma-terials to demonstrate

30、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 availability of oxygen must becarefully controlled

31、 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 SHEETX1.1 Fig. X1.1 is an example of a typical r

32、eport sheet fortest data.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:C05-1009.C1179 91 (2010)13ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedi

33、n 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 responsible technical committee and mu

34、st 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 receive careful consideration at a meeting of th

35、eresponsible 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 C70

36、0, 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).FIG. X1.1 Sample Oxidation Test Data SheetC1179 91 (2010)14