1、Designation: E 1447 05Standard Test Method forDetermination of Hydrogen in Titanium and Titanium Alloysby the Inert Gas Fusion Thermal Conductivity/InfraredDetection Method1This standard is issued under the fixed designation E 1447; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method applies to the determination of hydro-
3、gen in titanium and titanium alloys in concentrations from0.0006 to 0.0260 %.1.2 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 appro-priate safety and health practices and determ
4、ine the applica-bility of regulatory limitations prior to use. For specificprecautionary statements, see Section 9.2. Referenced Documents2.1 ASTM Standards:2C 696 Test Methods for Chemical, Mass Spectrometeric,and Spectrochemical Analysis of Nuclear-Grade UraniumDioxide Powders and PelletsE50 Pract
5、ices 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 MaterialsE 1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analyt
6、ical 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 testmethod, see Terminology E 135 and E 1914.4. Summary of Test Method4.1 The specimen, contained in a small, sin
7、gle-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 from other liberated gases such as carbon monoxide andfinally measured in a thermal conductivity cell.4.2
8、Alternately, hydrogen is converted to H2O by passingthe gas stream over heated copper oxide and subsequentlymeasuring in an appropriate IR cell.4.3 This test method is written for use with commercialanalyzers equipped to carry out the above operations automati-cally and is calibrated using reference
9、 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 thistest method will be trained analysts capable of performingcommon laboratory procedures skillfully and safely. It ise
10、xpected 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. Apparatus7.1 Fusion and Measurement ApparatusAutomatic hy-drogen determinator, consisting of an electrode furnace orinduction fur
11、nace; analytical gas stream impurity removalsystems; auxiliary purification systems and either a thermalconductivity cell hydrogen measurement system or an infraredhydrogen measurement system (Note 1).NOTE 1The apparatus and analysis system have been previouslydescribed in the Apparatus and Apparatu
12、s 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 operational requirements. Consult the instrument manufacturersinstructions for operational details.7.2 Graphite Cruci
13、blesThe crucibles are machined fromhigh-purity graphite. Use the size crucibles recommended bythe manufacturer of the instrument.7.3 Crucible TongsCapable of handling recommendedcrucibles.1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and R
14、elated Materials and is the directresponsibility of Subcommittee E01.06 on Ti, Zr, W, Mo, Ta, Nb, Hf.Current edition approved May 1, 2005. Published June 2005. Originallyapproved in 1992. Last previous edition approved in 2004 as E 1447 04.2For referenced ASTM standards, visit the ASTM website, www.
15、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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8. Rea
16、gents and Materials8.1 Acetone, low-residue.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 argon, nitrogen, and helium. Consult instrument man
17、ufacturersinstructions 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 manufacturer.8.7 Schutze ReagentIodine pentoxide ov
18、er silica gel.8.8 Copper Oxide WireTo convert H2to H2OinIRdetection instruments. Characteristics specified by the instru-ment manufacturer.9. Hazards9.1 For hazards to be observed in the use of this test method,refer to Practices E50.9.2 Use care when handling hot crucibles and operatingelectrical e
19、quipment 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 the required electrical power and waterconnections. Prepare th
20、e 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 Preparation11.1 Use solid form specimens prepared as directed in 11.2.Spe
21、cimens 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 to0.30 g (preferably by shearing). If necessary, abrade specimensurfaces with a clean file to remove contamination. Rinse thesample in a
22、cetone, and air dry. Weigh to 60.001 g. Aftercleaning and weighing, specimens must be handled withtweezers or forceps to prevent contamination.12. Calibration12.1 Calibration Reference MaterialsSelect only titaniumor titanium alloy reference materials (Note 3).NOTE 3Gas dosing: it is satisfactory to
23、 calibrate 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 Determi
24、nation 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 thei
25、nstrument manufacturer (Note 4). Use a fresh crucible eachtime.NOTE 4Flux 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 devi
26、ation for the three consecutivevalues exceeds 60.0001 %, then determine the cause, makenecessary corrections, and repeat 12.2.1 and 12.2.2 (Note 5).NOTE 5Refer to the instrument manufacturers instructions concern-ing the troubleshooting and correction of blank determinations notmeeting the above cri
27、terion.12.2.4 Enter the average blank value in the appropriatemechanism of the analyzer (Note 6), and refer to the manufac-turers instruction. This mechanism will electronically com-pensate for the blank value.NOTE 6If the unit does not have this function, the average blank mustbe subtracted from th
28、e total result (see Note 10).12.3 Calibration Procedure:12.3.1 Prepare at least four 0.15 to 0.30 g specimens of atitanium hydrogen reference material as directed in 11.2 (Note7). This titanium hydrogen reference material should have ahydrogen content greater than or approximately equal to theunknow
29、n samples within the scope of this test method (0.0006to 0.0260 %).NOTE 7The certificate of analysis may specify a minimum mass perspecimen greater than 0.15 to 0.30 g. In that case use the quantity specifiedon the certificate but not to exceed 0.35 g. None of the reference materialrequirements used
30、 in the ILS fell outside of the .15 to 0.30 g range.12.3.2 Follow the calibration procedure recommended bythe manufacturer. Analyze at least three reference materialspecimens to determine the calibration slope. Treat eachspecimen as directed in 13.2 before proceeding to the next one(Note 8).NOTE 8So
31、me instruments have expanded computer capabilities thatallow multi-point calibration which may improve the accuracy andprecision of the calibration over the single-point calibration methodologyas tested in the current interlaboratory study.12.3.3 Confirm the calibration by analyzing the fourthspecim
32、en of the titanium hydrogen reference material (Note 9).The ILS used an acceptance criterion where the value fellwithin the allowable limits of the certified value. An alternateprocedure can be implemented where this value should agreewith the certified value within the limits of a prediction interv
33、alcalculated using Eq 1. The prediction interval is defined as therange of values bounded by the analysis value -p and theanalysis value +p. If the prediction interval does not encompassthe certified value, determine and correct the cause, and repeat12.3.1 and 12.3.2 (Note 10).NOTE 9Confirmation of
34、the calibration does not ensure accuracy. Theaccuracy of this test method is largely dependent upon the absence of biasE1447052in the hydrogen values assigned to the reference materials and upon thehomogeneity of these materials.NOTE 10See the instrument manufacturers instructions concerningthe trou
35、bleshooting and correcting of errant calibration.p 5 t S1 11=nD s (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)
36、, ands = standard deviation of n replicates in 12.3.2 (Note 11).NOTE 11Here, 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 shoul
37、d determine and correct the cause, and repeat12.3.1 through 12.3.3.12.3.4 Confirm calibration linearity by analyzing at leastthree specimens of a mid-range titanium hydrogen referencematerial. Calculate the average and standard deviation(s) ofthese results. In the absence of bias among the reference
38、materials, the average result for this reference material shouldagree with the certified value within a prediction intervaldefined by the repeatability of the measurement system at themid-range of the calibration (Note 12). This prediction intervalmay be calculated using Eq 1 and the s and n values
39、for themid-range reference material. If the prediction interval doesnot encompass the certified value, determine and correct thecause and repeat 12.3.1 and 12.3.4 (Note 13).NOTE 12Typically, repeatability standard deviation is a function ofthe concentration of the analyte. Compare the values labeled
40、 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 13The presence of bias between the reference material used in12.3.2 and the reference material use
41、d in 12.3.4 may cause the calibrationto appear to be non-linear. This cannot be corrected by making adjust-ments to the instrument.13. Procedure13.1 Assemble the apparatus and condition it as directed inSection 10.13.2 Procedure for Operation:13.2.1 Set the analyzer to operate mode.13.2.2 Prepare a
42、0.15 to 0.30-g specimen as directed in 11.2.13.2.3 Place a 0.15 to 0.30-g specimen in the loadingdevice. If the instrument does not have this feature, refer to themanufacturers recommended procedure regarding entry ofsample.13.2.4 Enter the sample weight as recommended by themanufacturer.13.2.5 Plac
43、e a crucible containing high-purity tin as mea-sured in 12.2.2 on the furnace electrode/pedestal assembly andclose the furnace.13.2.6 Start the analysis cycle, referring to the manufactur-ers recommended procedure.14. Calculation14.1 The reading will be direct if the blank and weight havebeen entere
44、d correctly into the appropriate portion of theanalyzer (Note 14).NOTE 14If the analyzer does not offer these functions, calculate thehydrogen content by the following method: Dial the sample weight or amultiple of the sample weight on the weight compensator and use thefollowing formula (Eq 2) for t
45、he calculation of the result:Hydrogen, % 5A 2 B! 3 CD(2)where:A = sample DVM reading,B = blank DVM reading,C = weight compensator setting, andD = sample weight, g.15. Precision and Bias15.1 Precision3Eleven laboratories cooperated in testingeight samples in triplicate. The data are presented in Tabl
46、e 1.The testing and statistical analysis were performed in accor-dance with the provisions of Practice E 1601, Plan A. Sixinstruments were of the thermal conductivity hydrogen mea-surement system configuration and five instruments were of the3Supporting data are available from ASTM International Hea
47、dquarters. RequestRR: E01.1004.TABLE 1 Hydrogen in Titanium Metal Statistical InformationAMaterial#LabsCertifiedValue(g/g)ILSAnalyzedMean(g/g)Difference(g/g)CertifiedPrecision(g/g)Minimum SD(Sm, PracticeE 1601)ReproducabilitySD (SR, PracticeE 1601)ReproducabilityIndex(R, PracticeE 1601)Rrel %BCR 318
48、B10 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 95.8 2.2 5 3.42 4.00 11.19 11.7NBS 354D11 215 213.2 1.8 6 3.36 3.66 10.24 4.80NIST 2454E11 . 219.5 . . 5.80 11.35
49、 31.78 14.5CEZUS HHC10 . 260.1 . . 4.45 11.72 32.80 12.6AInterlaboratory Study conducted in accordance with Practice E 1601, Plan A.BCertified Reference Material: Commission of the European Communities, Community Bureau of Reference.CReference Material :CEZUS, Ugine, France.DStandard Reference Material: National Institute of Standards and Technology, formerly National Bureau of Standards.EStandard Reference Material (under development): National Institute of Standards and Technology. Material is in chip form.E1447053infrared hydrogen measu
