1、Designation: E 1447 09Standard Test Method forDetermination of Hydrogen in Titanium and Titanium Alloysby Inert Gas Fusion Thermal Conductivity/Infrared DetectionMethod1This standard is issued under the fixed designation E 1447; the number immediately following the designation indicates the year ofo
2、riginal 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. Scope1.1 This test method applies to the determination of hydro-gen i
3、n titanium and titanium alloys in concentrations from0.0006 % to 0.0260 %.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 all of thesafety concerns, if any, associated with its u
4、se. 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. For specifichazards, see Section 9.2. Referenced Documents2.1 ASTM Standards:2C 696 Test Methods for Chemical, Mass
5、Spectrometric, andSpectrochemical Analysis of Nuclear-Grade Uranium Di-oxide Powders and PelletsE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related
6、 MaterialsE 1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE 1914 Practice for Use of Terms Relating to the Develop-ment and Evaluation of Methods for Chemical Analysis3. Terminology3.1 DefinitionsFor definitions of terms used in this testmeth
7、od, see Terminology E 135 and E 1914.4. Summary of Test Method4.1 The specimen, contained in a small, single-use graphitecrucible, is fused under a flowing carrier gas atmosphere.Hydrogen present in the sample is released as molecularhydrogen into the flowing gas stream. The hydrogen is sepa-rated f
8、rom other liberated gases such as carbon monoxide andfinally measured in a thermal conductivity cell.4.2 Alternatively, hydrogen is converted to water by passingthe gas stream over heated copper oxide and subsequentlymeasuring in an appropriate infrared (IR) cell.4.3 This test method is written for
9、use with commercialanalyzers equipped to perform the above operations automati-cally and is calibrated using reference materials of knownhydrogen content.5. Significance and Use5.1 This test method is intended to test for compliance withcompositional specifications. It is assumed that all who use th
10、istest method will be trained analysts capable of performingcommon laboratory procedures skillfully and safely. It isexpected that the work will be performed in a properlyequipped laboratory.6. Interferences6.1 The elements ordinarily present in titanium and itsalloys do not interfere.7. Apparatus7.
11、1 Fusion and Measurement ApparatusAutomatic hy-drogen determinator, consisting of an electrode furnace orinduction furnace; analytical gas stream impurity removalsystems; auxiliary purification systems and either a thermalconductivity cell hydrogen measurement system or an infraredhydrogen measureme
12、nt system (Note 1).NOTE 1The apparatus and analysis system have been previouslydescribed in the Apparatus and Apparatus and Equipment sections of TestMethods C 696. Several models of commercial analyzers are available andpresently in use in industry. Each has its own unique design characteristicsand
13、 operational requirements. Consult the instrument manufacturersinstructions for operational details.1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and is the directresponsibility of Subcommittee E01.06 on Ti, Zr, W, Mo
14、, Ta, Nb, Hf, Re.Current edition approved March 1, 2009. Published March 2009. Originallyapproved in 1992. Last previous edition approved in 2005 as E 1447 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
15、ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Copyright by ASTM Intl (all rights reserved); Mon Apr 20 21:06:08 EDT 2009Downloaded/pr
16、inted byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.7.2 Graphite CruciblesThe crucibles are machined fromhigh-purity graphite. Use the size crucibles recommended bythe manufacturer of the instrument.7.3 Crucible TongsCapable of handling recommendedcrucibles.7.
17、4 Tweezers or ForcepsFor contamination-free samplehandling.8. Reagents and Materials8.1 Acetone, low-residue reagent grade or higher purity.8.2 Sodium Hydroxide on Clay Base, commonly known asAscarite II.8.3 High-Purity Carrier Gas (99.99 %)Argon, nitrogen,or helium (Note 2).NOTE 2Carrier gases vary
18、 by instrument model and include high-purity argon, nitrogen, and helium. Consult instrument manufacturersinstructions for proper gas recommendation.8.4 High-Purity Tin Metal (Low Hydrogen)Use the purityspecified by the instrument manufacturer.8.5 Magnesium Perchlorate, Anhydrone.8.6 Molecular Sieve
19、Characteristics specified by the in-strument manufacturer.8.7 Schutze ReagentIodine pentoxide over silica gel.8.8 Copper Oxide WireTo convert hydrogen to water inIR-detection instruments. Characteristics specified by the in-strument manufacturer.9. Hazards9.1 For hazards to be observed in the use of
20、 this test method,refer to Practices E50.9.2 Use care when handling hot crucibles and operatingelectrical equipment to avoid personal injury by either burn orelectrical shock.10. Preparation of Apparatus10.1 Assemble the apparatus as recommended by the manu-facturer.10.2 Test the furnace and analyze
21、r to ensure the absence ofgas leaks and make the required electrical power and waterconnections. Prepare the apparatus for operation in accordancewith the manufacturers instructions. Make a minimum of twodeterminations using a specimen as directed in 13.2 beforeattempting to calibrate the system or
22、to determine the blank.11. Sample Preparation11.1 Use solid form specimens prepared as directed in 11.2.Specimens must be of an appropriate size to fit into the graphitecrucible and should not exceed 0.30 g in weight.11.2 Cut the specimen to the approximate size of 0.15 g to0.30 g (preferably by she
23、aring). For specimens of unknownhistory or suspected surface contamination, abrade specimensurfaces with a clean file to remove contamination. Othermethods, such as turning down on a lathe, may be employedfor reducing sample size and removing the surface of thesample (Note 3). Rinse the sample in ac
24、etone, and air dry.Weigh to 6 0.001 g. Samples shall be handled only withtweezers or forceps after cleaning and weighing to preventcontamination.NOTE 3Regardless of the method used, the sample must not beallowed to overheat, as this will adversely affect the results of the analysis.Indications that
25、the sample has overheated while being worked mayinclude discoloration of the metal or the sample becoming too hot tohandle without tools.12. Calibration12.1 Calibration Reference MaterialsSelect only titaniumor titanium alloy reference materials (Note 4).NOTE 4Gas dosing: it is satisfactory to calib
26、rate the unit by dosingknown volume(s) of hydrogen gas into the detection system. If theinstrument has this feature, refer to the manufacturers recommendedprocedure. In this case instrument response must always be verified byanalyzing titanium or titanium alloy reference materials.12.2 Determination
27、 of Crucible/Tin Blank Reading:12.2.1 If the instrument is equipped with an electronic blankcompensator, adjust to zero, and proceed with the determina-tion of the blank value.12.2.2 Make at least three blank determinations as directedin 13.2 using the weight of tin flux as recommended by theinstrum
28、ent manufacturer (Note 5). Use a fresh crucible eachtime.NOTE 5Flux weight is dependent upon the model of the instrumentand the manufacturers instruction. Refer to the manufacturers instruc-tions and recommendations.12.2.3 If the average blank value exceeds 0.0000 % 60.0001 %, or a standard deviatio
29、n for the three consecutivevalues exceeds 6 0.0001 %, then determine the cause, makenecessary corrections, and repeat 12.2.1 and 12.2.2 (Note 6).NOTE 6Refer to the instrument manufacturers instructions concern-ing the troubleshooting and correction of blank determinations notmeeting the above criter
30、ion.12.2.4 Enter the average blank value in the appropriatemechanism of the analyzer (Note 7) according to the manu-facturers instruction. This mechanism will electronically com-pensate for the blank value.NOTE 7If the unit does not have this function, the average blank mustbe subtracted from the to
31、tal result.12.3 Calibration Procedure:12.3.1 Prepare at least four 0.15 g to 0.30 g specimens (atleast one specimen if calibrating by gas dosing) of a titaniumhydrogen reference material as directed in 11.2. This titaniumhydrogen reference material should have a hydrogen contentgreater than or appro
32、ximately equal to the unknown sampleswithin the scope of this test method (0.0006 % to 0.0260 %).12.3.2 Follow the calibration procedure recommended bythe manufacturer. Analyze at least three reference materialspecimens to determine the calibration slope (Note 8). Treateach specimen as directed in 1
33、3.2 before proceeding to the nextone (Note 9).NOTE 8For calibration by gas dosing, perform at least three gas doseanalyses to determine the calibration slope. Refer to instrument manufac-turers instructions.NOTE 9Some instruments have expanded computer capabilities thatallow multi-point calibration
34、which may improve the accuracy andprecision of the calibration over the single-point calibration methodologyas tested in the current interlaboratory study (ILS).E1447092Copyright by ASTM Intl (all rights reserved); Mon Apr 20 21:06:08 EDT 2009Downloaded/printed byGuo Dehua (CNIS) pursuant to License
35、 Agreement. No further reproductions authorized.12.3.3 Confirm the calibration by analyzing a specimen oftitanium hydrogen reference material (Note 10). The ILS usedan acceptance criterion where the value fell within the allow-able limits of the certified value. An alternate procedure can beimplemen
36、ted where this value should agree with the certifiedvalue within the limits of a prediction interval calculated usingEq 1. The prediction interval is defined as the range of valuesbounded by the analysis value -p and the analysis value +p.Ifthe prediction interval does not encompass the certified va
37、lue,determine and correct the cause, and repeat 12.3.1 and 12.3.2(Note 11). Either acceptance limit criterion is acceptable forroutine operation.NOTE 10Confirmation of the calibration does not ensure accuracy.The accuracy of this test method is largely dependent upon the absence ofbias in the hydrog
38、en values assigned to the reference materials and uponthe homogeneity of these materials.NOTE 11See the instrument manufacturers instructions concerningthe troubleshooting and correcting of errant calibration.p 5 t S1 11=nD s (1)where:p = one-half the prediction interval,n = number of replicates use
39、d in 12.3.2,t = students t chosen for the 95 % confidence level for nreplicate measurements (for example: t = 2.35 when n= 3, 2.13 when n = 4, 2.02, when n = 5), ands = standard deviation of n replicates in 12.3.2 (Note 12).NOTE 12Here, s should be comparable to Sm, the repeatabilitystandard deviati
40、on, given in Table 1.Ifs Sm, there is evidence that therepeatability of the particular instrument is not acceptable for use with thistest method. The user should determine and correct the cause, and repeat12.3.1 through 12.3.3.12.3.4 Confirm calibration linearity by analyzing a mid-range (Note 13) t
41、itanium hydrogen reference material, usingthe limits stated on the certified value as an acceptance range.Alternatively, analyze at least three specimens of a mid-range(Note 13) titanium hydrogen reference material. Calculate theaverage and standard deviation(s) of these results. In theabsence of bi
42、as among the reference materials, the averageresult for this reference material should agree with the certifiedvalue within a prediction interval defined by the repeatabilityof the measurement system at the mid-range of the calibration(Note 14). This prediction interval may be calculated using Eq1 a
43、nd the s and n values for the mid-range reference material.If the prediction interval does not encompass the certifiedvalue, determine and correct the cause and repeat 12.3.1 and12.3.4 (Note 15).NOTE 13Commercially available reference materials are not alwaysavailable at the concentration required t
44、o have a true mid-point check. Themid-range material must have a hydrogen concentration that is above thelimit of detection, but below that of the high calibration point, preferablyas close to the mid-point of the calibration curve as possible.NOTE 14Typically, repeatability standard deviation is a
45、function ofthe concentration of the analyte. Compare the values labeled ILS AnalyzedMean in Table 1 with the values for Minimum SD (Sm) to see a typicaltrend for laboratories using this test method. If your results are notcomparable, investigate and correct the cause.NOTE 15The presence of bias betw
46、een the reference material used in12.3.2 and the reference material used in 12.3.4 may cause the calibrationto appear to be non-linear. This cannot be corrected by making adjust-ments to the instrument.12.3.5 One or more continuing calibration verificationsmust be performed prior to and upon complet
47、ion of a period ofcontinuous operation, and throughout this period with a pre-determined minimum frequency to be established by eachindividual test facility. The acceptance range for the verifica-tion material may be the limits stated on the certified value forthe reference material, or may be calcu
48、lated using Eq 1 and thes and n values for multiple analyses of the verification material.If a continuing calibration verification indicates an out ofcalibration condition, stop analysis. Results must be supportedby acceptable preceding and subsequent verifications to bereported.12.4 Calibration Fre
49、quency:12.4.1 It is the responsibility of the user to document thefrequency of blank determination (12.2.1-12.2.4), routine cali-bration and confirmation (12.3.2 and 12.3.3) and linearityconfirmation (12.3.4), and the conditions under which blankdetermination or recalibration, or both, beyond this frequencyis required (examples may include changing reagents, chang-ing gas cylinders or a personnel shift change).13. Procedure13.1 Assemble the apparatus and condition it as directed inSection 10.TABLE 1 Hydrogen in Titanium Metal Statistical Info
