1、Designation: E 159 06Standard Test Method forLoss of Mass in Hydrogen for Cobalt, Copper, Tungsten,and Iron Powders (Hydrogen Loss)1This standard is issued under the fixed designation E 159; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, 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. Scope*1.1 This test method covers the determination of the mass ofhydrogen-reducible constituents in the f
3、ollowing metal pow-ders: cobalt, copper, iron, and tungsten.1.2 This test method is useful for cobalt, copper, and ironpowders in the range from 0.05 to 3.0 % oxygen, and fortungsten powder in the range from 0.01 to 0.50 % oxygen.1.3 This test method does not measure the oxygen containedin oxides su
4、ch as silicon oxide (SiO2), aluminum oxide(Al2O3), magnesium oxide (MgO), calcium oxide (CaO),titanium dioxide (TiO2), and so forth that are not reduced byhydrogen at the test temperatures.1.4 For total oxygen content, vacuum or inert gas fusionmethods are available (see Test Methods E 1019).1.5 The
5、 values stated in SI units are to be regarded as thestandard. The values given in parentheses are provided forinformation only.1.6 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 a
6、ppro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B 215 Practices for Sampling Metal PowdersB 243 Terminology of Powder MetallurgyE 691 Practice for Conducting an Interlaboratory Study toDetermin
7、e the Precision of a Test MethodE 1019 Test Methods for Determination of Carbon, Sulfur,Nitrogen, and Oxygen in Steel and in Iron, Nickel, andCobalt Alloys3. Terminology3.1 DefinitionsDefinitions of powder metallurgy termscan be found in Terminology B 243. Additional descriptiveinformation on powder
8、 metallurgy is available in the RelatedMaterial section of Vol 02.05 of the Annual Book of ASTMStandards.4. Summary of Test Method4.1 This test method consists of subjecting a sample ofpowder to the action of a hydrogen-containing gas understandard conditions of temperature and time and measuring th
9、eresulting loss of mass.5. Significance and Use5.1 The oxygen content of a powder affects both its greenand sintered properties.5.2 Hydrogen loss is a term widely used in the powdermetallurgy industry even though the measurement representsan approximate oxygen content of the powder.5.3 Oxygen is the
10、 most common hydrogen-reducible con-stituent of metal powders, and this procedure may be used as ameasure of oxygen, reducible under the test conditions, if otherinterfering elements are absent.6. Interferences6.1 If carbon or sulfur is present, or both, are present, theywill be largely removed in t
11、he test. Their loss in mass isincluded in the total loss in mass measurement and must besubtracted from the total mass loss.6.2 If metals or compounds are present that vaporize at thetest temperature (such as cadmium, lead, zinc, and so forth),their effect is included in the loss of mass measurement
12、 andmust be subtracted from the total mass loss.6.3 If some components are present that are oxidized orhydrided during the test, there is a gain in mass that must beadded to the total mass loss.7. Apparatus7.1 Furnace, capable of operating at the prescribed tem-perature.7.2 Temperature Control, capa
13、ble of maintaining tempera-tures to 615 C (627 F).1This test method is under the jurisdiction of ASTM Committee B09 on MetalPowders and Metal Powder Products and is the direct responsibility of Subcom-mittee B09.02 on Base Metal Powders.Current edition approved Nov. 1, 2006. Published December 2006.
14、 Originallyapproved in 1986. Last previous edition approved in 2000 as E 159 00.2For 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
15、onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.3 Gastight Ceramic or Metallic Combustion Tube.7.4 Flow Meter, to measure flow of hydrogen.7.5 Com
16、bustion Boat, composed of alundum, quartz, ornickel, depending on the test conditions. The boat shall be ofsuch dimensions, for example 75 mm long and 12 mm wide,that the thickness of powder, when uniformly distributed, doesnot exceed 3 mm (18 in.).7.6 Balance, suitable for determining mass to the n
17、earest0.001 g.8. Reagents8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are av
18、ailable.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.8.2 Dissociated Ammonia, having a dew point lowerthan 40 C (40 F). May be used interchangeably with thehydrogen speci
19、fied in section 8.3.8.3 Hydrogen, having an oxygen content less than 20 ppmand a dew point lower than 40 C (40 F).8.4 Nitrogen, having an oxygen content less than 20 ppmand a dew point lower than 40 C (40 F).9. Test Specimen9.1 Obtain the test specimen in accordance with the proce-dure described in
20、Practices B 215.9.2 The test specimen shall weigh approximately 5 g.10. Procedure10.1 Spread the test specimen to a uniform depth in acombustion boat that has been preconditioned to a constantmass and weighed to the nearest 0.001 g. The depth of powderin the boat should be approximately 3 mm (18 in.
21、). Then weighthe boat and specimen to the nearest 0.001 g.10.2 Pass the nitrogen through the combustion tube for aperiod of at least 1 min before inserting the combustion boat atthe center of the zone of uniform temperature of the furnace.10.2.1 For cobalt, the temperature is 875 C (1607 F).10.2.2 F
22、or copper, the temperature is 875 C (1607 F).10.2.3 For iron, the temperature is 1120 C (2050 F).10.2.4 For tungsten, the temperature is 1120 C (2050 F).10.3 Start the flow of hydrogen and stop the flow ofnitrogen. Record the time when the hydrogen is introduced.10.4 Maintain a positive flow of hydr
23、ogen through thesystem for the time of reduction during which the temperatureof the furnace shall be held within 615 C (625 F).10.4.1 For cobalt, the time shall be 30 min.10.4.2 For copper, the time shall be 30 min.10.4.3 For iron, the time shall be 60 min.10.4.4 For tungsten, the time shall be 60 m
24、in.10.5 At the end of the prescribed time, discontinue the flowof hydrogen and restart the flow of nitrogen into the tube.10.6 After nitrogen has been flowing through the combus-tion tube for at least 1 min, open the tube and withdraw theboat under nitrogen atmosphere to the cooler part of thecombus
25、tion tube.10.7 Allow the specimen to cool in the nitrogen atmospherefor 15 to 30 min, then remove the specimen from the tube andpermit it to cool to room temperature in a desiccator.10.8 When the boat has cooled to room temperature, re-weigh it to the nearest 0.001 g.10.9 Alternative Test MethodThe
26、following alternativetest method may be used satisfactorily if the use of nitrogen isimpractical.10.9.1 Bring the furnace with the combustion tube insertedup to the prescribed temperature.10.9.2 Spread the test specimen to a uniform depth in thepreweighed combustion boat. The depth of powder in the
27、boatshould be approximately 3 mm (18 in.). Then weigh the boatand specimen to the nearest 0.001 g.10.9.3 Place the boat containing the specimen in the com-bustion tube through which dry hydrogen is flowing. The boatis inserted through the hydrogen discharge end of the tube thatis open to the atmosph
28、ere and at which hydrogen is burning.Place the boat within and at the center of the zone of uniformtemperature of the furnace and record the time of insertion.10.9.4 Maintain a positive flow of dry hydrogen through thesystem for the time of reduction, during which the temperatureof the furnace shall
29、 be held within 615 C (625 F).10.9.5 At the end of this period, either withdraw the entirecombustion tube with hydrogen still flowing through it fromthe furnace and set it on a rack until the specimen has cooledto a point at which it can be removed from the hydrogenatmosphere without danger of reoxi
30、dation, or, with the hydro-gen still flowing, withdraw the combustion boat from theheated section of the combustion tube and allow the boat tocool in the hydrogen atmosphere until there is no danger ofreoxidation. This normally takes 15 to 30 min. Then removethe specimen from the tube and permit it
31、to cool to roomtemperature in a desiccator.10.9.6 When the specimen has cooled to room temperature,reweigh it in the boat to the nearest 0.001 g.11. Calculation11.1 Calculate the mass loss as follows:Loss in mass, % 5A BA C3 100 (1)where:A = original mass of boat and powder specimen, g;B = mass of b
32、oat and powder specimen after reduction, g;andC = original mass of the boat, g.11.2 If the hydrogen loss value calculated in 11.1 is to beused as the oxygen content of the powder, correct the valueobtained in accordance with 6.1-6.3.3Reagent Chemicals, American Chemical Society Specifications , Amer
33、icanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by theAmerican Chemical Society, see Reagent Chemicals and Standards,byJoseph Rosin, D. Van Nostrand Co., Inc., New York, NY., and the United StatesPharmacopeia and National Formulary, U.S. Pharmacopeial Conve
34、ntion, Inc.(USPC), Rockville, MD.E15906212. Report12.1 Results shall be reported as percent loss in mass to thenearest 0.01 %.13. Precision and Bias13.1 A statement of precision provides guidelines as to thekind of variability that can be expected between test resultswhen the method is used in one o
35、r more reasonably competentlaboratories.13.2 The precision of this test method has not been deter-mined by a statistically valid interlaboratory test because of thelimited number of participating laboratories (less than six).13.3 The following precision data were developed using theprocedures contai
36、ned in Test Method E 159 from an interlabor-tory test conducted by four laboratories in 1994. The percentloss in mass in hydrogen was determined for four samples, acobalt powder, a copper powder, an iron powder, and atungsten powder. Except for the use of only four laboratories,Practice E 691 was fo
37、llowed for the design and analysis of thedata. The details are given in an ASTM research report.13.4 The precision information given below is for theresults. The results were obtained from the running of threereplicates by each lab on each sample.Cobalt Copper Iron TungstenAverage, % 0.45 0.15 0.22
38、0.47r, % 0.03 0.03 0.03 0.09R, % 0.12 0.03 0.07 0.1113.5 Repeatability, r, is a measure of the variability betweentest results obtained within a single laboratory in the shortestpractical period of time by a single operator with a specific setof test apparatus using test specimens taken at random fr
39、om asingle quantity of homogeneous material.13.6 Reproducibility, R, is a measure of the variabilitybetween test results obtained in different laboratories using testspecimens taken at random from a single quantity of homoge-neous material.13.7 Bias cannot be stated since there is no certifiedrefere
40、nce material.14. Keywords14.1 chemical analysis; cobalt powder; copper powder;hydrogen loss; iron powder; metal powders; oxygen content;tungsten powderSUMMARY OF CHANGESCommittee B09 has identified the location of selected changes to this standard since the last issue (Oct. 10,2000) that may impact
41、the use of this standard. (Approved Nov. 1, 2006.)(1) Changed the title.(2) Broke the Scope into a number of sections.(3) Removed second sentence from the previous scope andplaced it in a Summary of Test Method section.(4) Made a reference to methods E 1019 in Section 1.4 of therevised Scope.(5) Inc
42、luded an alternative option for the procedure in Section10.9.5 (former Section 9.9.5).(6) Deleted reference to the acceptability limits presented inthe former Section 11.1 (revised Section 12.1) as the limitswere not consistent with those in the Precision Section.ASTM International takes no position
43、 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 the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.T
44、his 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. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM In
45、ternational Headquarters. Your comments will receive 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 show
46、n 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).E159063
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