1、Designation: E1447 09 (Reapproved 2016)Standard Test Method forDetermination of Hydrogen in Titanium and Titanium Alloysby Inert Gas Fusion Thermal Conductivity/Infrared DetectionMethod1This standard is issued under the fixed designation E1447; the number immediately following the designation indica
2、tes the year 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. Scope1.1 This test method applies to the determinatio
3、n of hydro-gen in 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, assoc
4、iated 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. For specifichazards, see Section 9.2. Referenced Documents2.1 ASTM Standards:2C696 Test Methods for
5、Chemical, Mass 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 MaterialsE135 Terminology Relating to Analytical Chemistry forMetals, Ore
6、s, and Related MaterialsE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE1914 Practice for Use of Terms Relating to the Develop-ment and Evaluation of Methods for Chemical Analysis(Withdrawn 2016)33. Terminology3.1 DefinitionsFor definitions o
7、f terms used in this testmethod, see Terminology E135 and E1914.4. 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. T
8、he hydrogen is sepa-rated from 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
9、test method is written for 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
10、assumed that all who use thistest 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 n
11、ot interfere.7. Apparatus7.1 Fusion and Measurement ApparatusAutomatic hydro-gen determinator, consisting of an electrode furnace or induc-tion furnace; analytical gas stream impurity removal systems;auxiliary purification systems and either a thermal conductivitycell hydrogen measurement system or
12、an infrared hydrogenmeasurement system (Note 1).NOTE 1The apparatus and analysis system have been previouslydescribed in the Apparatus and Apparatus and Equipment sections of Test1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Ma
13、terials and is the directresponsibility of Subcommittee E01.06 on Ti, Zr, W, Mo, Ta, Nb, Hf, Re.Current edition approved Aug. 1, 2016. Published August 2016. Originallyapproved in 1992. Last previous edition approved in 2009 as E1447 09. DOI:10.1520/E1447-09R16.2For referenced ASTM standards, visit
14、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 onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM
15、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Methods C696. Several models of commercial analyzers are available andpresently in use in industry. Each has its own unique design characteristicsand operational requirements. Consult the instrument ma
16、nufacturersinstructions for operational details.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.7.4 Tweezers or ForcepsFor contamination-free
17、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 by instrument model and include high-purity
18、 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 SieveCharacteristics specified by the in-strument
19、 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 this test method,refer to Practices E50.9.2
20、 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 analyzer to ensure the absence ofgas leaks and make
21、 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 to determine the blank.11. Sample Preparatio
22、n11.1 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 shearing). For specimens of unknownhistory or s
23、uspected 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 acetone, and air dry.Weigh to 6 0.001 g. Sampl
24、es 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 the sample has overheated while being worked
25、 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 calibrate the unit by dosingknown volume(s) of hy
26、drogen 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 of Crucible/Tin Blank Reading:12.2.1 If the
27、 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 theinstrument manufacturer (Note 5). Use a fresh cruci
28、ble 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 deviation for the three consecutivevalues exceeds 6
29、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 criterion.12.2.4 Enter the average blank value in
30、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 total result.12.3 Calibration Procedure:12.3.1
31、 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 approximately equal to the unknown sampleswithin
32、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 13.2 before proceeding to the nextone (Note 9
33、).E1447 09 (2016)2NOTE 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 which may improve the accura
34、cy andprecision of the calibration over the single-point calibration methodologyas tested in the current interlaboratory study (ILS).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 withi
35、n the allow-able limits of the certified value. An alternate procedure can beimplemented 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 an
36、d the analysis value +p.Ifthe prediction interval does not encompass the certified value,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 ac
37、curacy of this test method is largely dependent upon the absence ofbias in the hydrogen 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 tS
38、111=nDs (1)where:p = one-half the prediction interval,n = number of replicates used 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 (Not
39、e 12).NOTE 12Here, s should be comparable to Sm, the repeatabilitystandard deviation, 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 throug
40、h 12.3.3.12.3.4 Confirm calibration linearity by analyzing a mid-range (Note 13) titanium 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. Ca
41、lculate theaverage and standard deviation(s) of these results. In theabsence of bias 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 o
42、f the calibration(Note 14). This prediction interval may be calculated using Eq1 and 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 ava
43、ilable reference materials are not alwaysavailable at the concentration required to 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 cali
44、bration curve as possible.NOTE 14Typically, repeatability standard deviation is a 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
45、 notcomparable, investigate and correct the cause.NOTE 15The presence of bias between 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 mo
46、re continuing calibration verificationsmust be performed prior to and upon completion 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 t
47、he limits stated on the certified value forthe reference material, or may be calculated 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 ac
48、ceptable preceding and subsequent verifications to bereported.12.4 Calibration Frequency:12.4.1 It is the responsibility of the user to document thefrequency of blank determination (12.2.1 12.2.4), routinecalibration and confirmation (12.3.2 and 12.3.3) and linearityconfirmation (12.3.4), and the co
49、nditions under which blankdetermination or recalibration, or both, beyond this frequencyTABLE 1 Hydrogen in Titanium Metal Statistical InformationAMaterial#LabsCertifiedValue(g/g)ILSAnalyzedMean(g/g)Difference(g/g)CertifiedPrecision(g/g)Minimum SD(Sm, PracticeE1601)ReproducabilitySD (SR, Prac-ticeE1601)ReproducabilityIndex(R, PracticeE1601)Rrel %BCR 318B10 12.2 11.4 0.8 0.8 0.44 1.01 2.83 24.9CEZUS LHC11 . 20.3 . . 1.64 2.63 7.36 36.3NBS 352D11 32 27.4 4.6 2 1.43 1.96 5.47 20.0CEZUS TIV25C11 . 90.2 . . 1.44 5.31 14.90 16.5NBS 353D11 98 9
