1、Designation: C1179 91 (Reapproved 2010)1C1179 15 An 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
2、 oforiginal 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.1 NOTEUpdated units of measurement throughout the standard editorial
3、ly in May 2010.1. Scope Scope*1.1 This test method provides a comparative oxidation mass loss of manufactured carbon and graphite materials in air.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not
4、purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Summary of Test Method2.1 The test method
5、 determines mass loss characteristics of carbon and graphite articles in air as a function of temperature andtime by subjecting standard size specimens to muffle furnace exposure and then comparing pre-test and post-test mass differentials.3. Significance and Use3.1 This test method is primarily con
6、cerned with the oxidation mass loss of manufactured carbon and graphite materials in airat temperatures from 371371 C to 677C.677 C.3.2 The test method will provide acceptable results at preselected test temperatures that yield less than 10 % mass loss in 100h. 100 h. These results can be used to de
7、termine relative service temperatures.4. Interferences4.1 Results can be affected by materials released by the furnace walls or furniture.These materials may be present from previousoxidation test samples or other furnace use. It is recommended that the furnace be operated at 1093C1093 C for 1 h 1 h
8、 priorto use for oxidation mass loss testing.4.2 The validity of this test method depends upon the availability of oxygen to the test specimen. The door of the furnace shallbe kept closed to maintain temperature control; however, the furnace door shall not be sealed, rendering the door airtight.4.3
9、Due to factors beyond the scope of the test method that might cause significant differences, this test method is only usefulfor comparative results.5. Apparatus5.1 Muffle Furnace, with automatic temperature regulation with64C precision. Furnace chamber volume 983983 cm3 to 2458cm2458 cm3.NOTE 1Comme
10、rcially available muffle furnaces advertised to achieve 611C611 C can be set up to achieve the necessary precision.5.2 Thermocouple, K-type (chromel/alumel with Type 304 stainless steel sheath).5.3 Digital Thermometer, for temperature readout.5.4 Crucible Tongs.1 This test method is under the jurisd
11、iction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.F0 on Manufactured Carbon and Graphite Products.Current edition approved May 1, 2010Dec. 1, 2015. Published May 2010January 2016. Originally approved in 1991.
12、 Last previous edition approved in 2005 as C1179 91 (2005).(2010)1. DOI: 10.1520/C1179-91R10E01.10.1520/C1179-15.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not
13、be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end
14、of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.5 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 0.001-g0.001 g resolu
15、tion.5.10 Desiccator, charged with indicating desiccant.6. Sample Preparation6.1 All specimens are to be handled with lint-free nylon gloves or equivalent during all machining, handling, impregnation, andtesting. Specimens should be kept free of contamination by placing them on clean nonmetallic sur
16、faces during all operations. Oncethe specimens have been oxidized, direct handling is not recommended.6.2 Test specimens are to consist of right cylinders 25.4-mm25.4 mm diameter by 25.4 mm long 6 0.3 mm. 25.4 mm long60.3 mm. Specimens are to be machined all over with carbide-tipped tools to achieve
17、 a surface roughness visually comparableto 0.8-m.0.8 m. arithmetic average (AA).6.3 Wipe specimens with lint-free paper to remove carbon machining dust.6.4 Specimens and crucibles are to be clearly identified. To avoid sample contamination, use a carbide-tipped scribe to markthe specimens. Crucibles
18、 can be marked with ceramic ink.6.5 Place each specimen to be tested on its side (cylindrical surface) in a dried, tared crucible. Specimens are to be kept in thesame crucible for the test duration. Record the individual identification numbers for each specimen/crucible set.6.6 Dry the specimen/cruc
19、ible sets in a vented oven at 120120 C to 150C150 C for a minimum of 2 h. 2 h. Remove thespecimen/crucible sets and cool in a desiccator for a minimum of 30 min 30 min to achieve room temperature.7. Procedure7.1 Before the running of this test method, the operator should practice the transferring of
20、 similar shaped specimens fromfurnace to desiccator. The specimen/crucible set should be transferred so that the specimen is exposed to the atmosphere for nolonger than 30 s. 30 s. The desiccator should be in the immediate vicinity of the furnace.7.2 Preheat and stabilize the furnace to the designat
21、ed test temperature as verified by a monitoring thermocouple extending 50mm 50 mm into the chamber from the rear furnace wall (see Fig. 1).7.3 Just before testing, remove the specimen/crucible sets from the desiccator and immediately weigh on an analytical balanceto the nearest 0.001 g. 0.001 g. Rec
22、ord this data as pretest mass.7.4 Place two preweighed replicate specimen/crucible sets on a quartz glass tray or equivalent and insert into the furnacechamber so that the monitoring thermocouple is approximately centered between the specimens. Specimens are to be 2525 mm6 6 mm 6 mm apart and center
23、ed on the monitoring thermocouple (see Fig. 1).7.5 Monitor the thermocouple reading and maintain furnace chamber temperature within 64C64 C of the designated testtemperature. Record the temperature readings from the monitoring thermocouple on the data sheet for the following times for eachtest perio
24、d:7.5.1 Just before inserting samples into furnace,7.5.2 1 h 1 h after start, and7.5.3 Just before removing samples for weighing.7.6 Remove the specimen/crucible sets from the furnace every 25 61 h, 25 h 61 h, for a total test time of 100 h, 615 min.100 h, 615 min. Cool in a desiccator for a minimum
25、 of 30 min. 30 min. Weigh the specimen/crucible set on an analytical balanceto the nearest 0.001 g 0.001 g and record data as post-test mass for the specific test time interval at the designated test temperature.7.7 Repeat 7.4 through 7.6 for 100 h 100 h total test duration.8. Calculation8.1 Calcula
26、te the percent mass loss after each time interval and post test as follows:%mass loss51003F12SB 2 TA 2 TDG2 The sole source of supply of the crucible (Coors crucible 60048) known to the committee at this time is Coors Ceramics Co., 17750 W. 32nd Ave., Golden, CO 80401.If you are aware of alternative
27、 suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee,1 which you may attend.C1179 152where:A = pre-test specimen/crucible set mass,B = post-test specimen/crucible set mass, a
28、ndT = crucible tare mass.9. Report9.1 Report the following information:9.1.1 Specimen identification, including material designation and process lot number.9.1.2 Percent mass loss results for each specimen of 25, 50, 75, and 100 h 25 h, 50 h, 75 h, and 100 h at designated testtemperatures.10. Precis
29、ion and Bias310.1 PrecisionThe precision of this test method was determined via a round robin test among six laboratories. Two differentcarbon materials were selected to verify the validity of the test method at lower and higher test temperatures. Material A, acarbon-graphite, was evaluated at 427C4
30、27 C and Material B, an electrographite, was evaluated at 538C.538 C.All specimensof each material were from the same processing lot, with six specimens of each material evaluated by each laboratory. Evaluationswere conducted in muffle furnaces from various manufacturers with chamber volumes ranging
31、 from 983983 cm3 to 2458cm2458 cm3.10.2 The coefficient of variation for Material A within each laboratory was 0.1144 and between laboratories was 0.1140. ForMaterial B, the coefficient of variation within each laboratory was 0.1804 and between laboratories was 0.4120.10.3 Testing was deliberately c
32、onducted with different materials to demonstrate capabilities of the test method for both lowerand higher temperatures. The data shows that more variability exists at the higher test temperatures. At these more reactivetemperature regimes, furnace differences, temperature control variations, and the
33、 availability of oxygen must be carefullycontrolled to ensure consistent results.10.4 BiasNo statement on bias can be made because the true value of the oxidation mass loss has not been established.3 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting
34、 Research Report RR:C05-1009.NOTE 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 ChamberC1179 15311. Keywords11.1 air; carbon; graphite; oxida
35、tion-airoxidationAPPENDIX(Nonmandatory Information)X1. OXIDATION TEST DATA SHEETX1.1 Fig. X1.1 is an example of a typical report sheet for test data.SUMMARY OF CHANGESSubcommittee D02.F0 has identified the location of selected changes to this standard since the last issue(C1179 91 (2010)1) that may
36、impact the use of this standard. (Approved Dec. 1, 2015.)(1) Revised Keywords section.ASTM 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 determination of t
37、he 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 withdrawn.You
38、r 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 your comments
39、 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 mult
40、iple 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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ X1.1 Sample Oxidation Test Data SheetC1179 154
