1、Designation: E 1409 05Standard Test Method forDetermination of Oxygen and Nitrogen in Titanium andTitanium Alloys by the Inert Gas Fusion Technique1This standard is issued under the fixed designation E 1409; the number immediately following the designation indicates the year oforiginal adoption or,
2、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 covers the determination of oxygen intitanium and titanium allo
3、ys in concentrations from 0.01 to0.33 % and the determination of nitrogen in titanium andtitanium alloys in concentrations from 0.003 to 0.11 %1.2 The values stated in both inch-pound and SI units are tobe regarded separately as the standard. The values given inparentheses are for information only.1
4、.3 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 determine the applica-bility of regulatory limitations prior to use. Specific precau
5、-tionary statements are given in 8.8.2. Referenced Documents2.1 ASTM Standards:2E50 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 MaterialsE 173
6、Practice for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals3E 882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE 1019 Test Method for Determination of Carbon, Sulfur,Nitrogen, and Oxygen in Steel and in IronE 1601 Practice for Conductin
7、g 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 thismethod, refer to Terminology E 135 and E 1914.4.
8、 Summary of Test Method4.1 This test method is intended for use with automated,commercially available, inert gas fusion analyzers. Theseanalyzers typically measure both oxygen and nitrogen simul-taneously or sequentially utilizing parallel measurement sys-tems.4.2 The test sample, plus flux, is fuse
9、d in a graphite crucibleunder a flowing inert gas stream (Ar, He) at a temperaturesufficient to release oxygen and nitrogen. Oxygen combineswith carbon to form CO and nitrogen is released as N2.Depending on instrument design, the CO is oxidized to CO2orleft as CO and swept by the inert gas stream in
10、to either aninfrared or thermal conductivity detector. The detector outputis compared to that of reference materials and the result isdisplayed as percent oxygen. The nitrogen is swept by the inertgas stream (helium gas) into a thermal conductivity detector.The detector response is compared to that
11、of reference mate-rials and the result is displayed as percent nitrogen.4.3 In a typical instrument for the determination of nitrogen,the sample gases are swept with inert gas through heated rareearth/copper oxide that converts CO to CO2and H2to H2O.The CO2is absorbed on sodium hydroxide impregnated
12、 onclay, and the H2O is removed with magnesium perchlorate. Thenitrogen, as N2, enters the measuring cell and the thermistorbridge output is integrated and processed to display percentoxygen.5. Significance and Use5.1 This test method is primarily intended as a test forcompliance with compositional
13、specifications. It is assumedthat all who use this test method will be trained analystscapable of performing common laboratory procedures skill-fully and safely. It is expected that the work will be performedin a properly equipped laboratory.1This test method is under the jurisdiction of ASTM Commit
14、tee E01 onAnalytical Chemistry for Metals, Ores, and Related 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 1991. Last previous edition approved in 2004 as E 1409 04.2For r
15、eferenced 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 onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO
16、 Box C700, West Conshohocken, PA 19428-2959, United States.6. Interferences6.1 The elements usually present in titanium and its alloysdo not interfere but there is some evidence to suggest that lowpurity flux can cause some adsorption of the released oxygen.7. Apparatus7.1 InstrumentFusion and measu
17、rement apparatus, auto-matic oxygen and nitrogen determinator consisting of anelectrode furnace, provision for scrubbing impurities fromanalytical gas stream; infrared or thermal conductivity mea-surement system(s), or both, and auxiliary gas purificationsystems. (Note 1).NOTE 1The apparatus and ana
18、lysis systems have been previouslydescribed in Test Method E 1019. Several models of commercial oxygenand nitrogen determinators are available and presently in use by industry.Each has its own unique design characteristics and operational require-ments. Consult the instrument manufacturers instructi
19、on manual foroperational details.7.2 Graphite CruciblesThe crucibles must be made ofhigh-purity graphite and be of the dimensions recommended bythe instrument manufacturer.7.3 FluxWire baskets must be made of high-purity nickeland the dimensions must meet the requirements of the auto-matic sample dr
20、op, if present, on the instrument. (See Note 2.)NOTE 2In some instruments, nitrogen and oxygen are run sequen-tially and platinum is the required flux for nitrogen. High-purity platinumcan be substituted for nickel in the same ratio of flux to sample.7.4 TweezersSix inch tweezers made of solvent and
21、acid-resistant plastic.8. Reagents8.1 AcetoneResidue after evaporation must be 0.0005 %.8.2 Graphite PowderHigh-purity as specified by the in-strument manufacturer.8.3 Inert GasUse the purity and type specified by theinstrument manufacturer.8.4 Magnesium Perchlorate, Anhydrous4Used in the in-strumen
22、t to absorb water. Use the purity specified by theinstrument manufacturer.8.5 Nickel Flux Cleaning SolutionPrepare a fresh solutionby combining 75 mL of acetic acid, 25 mL of HNO3and2mLof HCl.8.6 Rare Earth/Copper OxideReagent used in some in-struments to oxidize CO to CO2for thermal conductivitydet
23、ection. Use the purity specified by the instrument manufac-turer.8.7 Sodium Hydroxide on Clay5Reagent used in someinstruments to absorb CO2. Use a purity specified by theinstrument manufacturer.8.8 Titanium Sample Pickle SolutionPrepare a fresh solu-tion of 3 parts 30 % H2O2and 1 part 48 % HF. HNO3m
24、ay besubstituted for 30 % H2O2(see Note 3). (WarningHF causesserious burns that may not be immediately painful; refer to theparagraph about HF in the Safety Precautions Section ofPractices E50.)NOTE 3In 2004, alternative sample preparation procedures (Section12) were tested by seven laboratories. Th
25、ree laboratories processed thesample materials by picking their samples in HF-H2O2(8.8). Two labora-tories utilized the HF-HNO3alternative pickle solution (8.8). Twolaboratories utilized abrasion (in this case diamond saw and shear) inaccordance with 12.4. The prepared samples were distributed among
26、 thelaboratories for analysis. Six laboratories analyzed these samples inrandom order under a single operator, single-day, single calibration samplerun. The results of this testing are given in Tables X1.1 and X2.1 foroxygen and nitrogen, respectively. In both cases, the analysis of theANOVA indicat
27、es that there is no significant difference at the 95 % levelof confidence for either oxygen or nitrogen due to the preparationtechnique.9. Hazards9.1 Use care when handling hot crucibles and operatingfurnaces to avoid personal injury by either burn or electricalshock.9.2 For precautions to be observ
28、ed in the use of HF andother reagents in this test method, refer to Practices E50.10. Preparation of Apparatus10.1 Assemble the apparatus as recommended by the manu-facturer. Make the required power, gas, and water connections.Turn on the instrument and allow sufficient time to stabilize theequipmen
29、t.10.2 Change the chemical traps and filters as required. Testthe furnace and analyzer to ensure the absence of leaks. Makea minimum of two test runs using a sample as directed in 14.3and 14.4 to condition the newly changed filters before attempt-ing to calibrate the system or to determine the value
30、 of theblank.11. Nickel Flux Preparation11.1 Nickel is necessary to flux the titanium fusion reactionbut contamination can be present on the surface of the nickelwere baskets that must be removed before use.11.2 Immerse the flux in nickel flux cleaning solution for 50to 60 s, then rinse in running w
31、ater for 2 to 3 min. Pour fluxonto paper towels to remove excess water. Place flux insealable glass container, rinse with acetone and decant. Re-place with fresh acetone and store flux under acetone untilused. (See Notes 4 and 5.)NOTE 4Nickel is necessary to flux the titanium fusion reaction butsign
32、ificant oxidation can be present on the surface of nickel wire basketsthat can cause interference with the analysis. Ultra high purity nickelbaskets are commercially available that do not require the nickel cleaningprocedure above. Their sufficiency must be verified by satisfactory blankdeterminatio
33、ns.NOTE 5The fluxing agent must be of proper size to be introducedthrough the sample drop mechanism and into the graphite crucible.12. Sample Preparation12.1 The optimum test sample is a pin approximately18 in.(5 mm) in diameter and nominally weighing 0.12 to 0.15 g. Cutthe sample to this approximat
34、e weight range.12.2 Leach the test sample in the titanium sample picklesolution (see 8.8, Warning in 8.8, and Note 4) until the surface4Known commercially as Anhydrone.5Known commercially as Ascarite II.E1409052is clean. This will normally require approximately 5 s from thetime of the initial vigoro
35、us reaction between the sample and thesolution.12.3 Immediately remove the reacting test sample withtweezers and rinse it twice with water and once with acetoneand allow to air dry. This test sample should now weighbetween 0.100 and 0.140 g.12.4 Alternatively, clean surfaces may be prepared on thete
36、st sample by filing or cutting off all outside edges, retainingonly fresh surfaces, and finishing by rinsing with acetone andair drying. The test sample should now weigh between 0.100and 0.140 g.12.5 All subsequent operations on the test sample and fluxmust be done without introducing contamination
37、to either. Useonly clean tweezers and never let the test sample or flux contactthe analysts skin. In the event this does happen, rinse thesample plus nickel basket with acetone and air dry beforeanalysis.13. Standardization13.1 StandardantsSelect only titanium or titanium alloyreference materials. S
38、elect one containing approximately 0.2 %oxygen and approximately 0.02 % nitrogen. The accuracy ofthe test method is dependent upon the accuracy of the methodsused to certify the oxygen and nitrogen concentrations of thereference materials, as well as upon their homogeneity. Thus,wherever possible, r
39、eference materials used to confirm instru-ment standardization should be NIST Standard ReferenceMaterials or other certified reference materials.13.2 Gas DosingAutomatic and manual gas dosing, rec-ommended by some manufacturers, can be used to set up theinstrument, but instrument response must be ve
40、rified by stan-dardization with titanium reference materials because of thefusion characteristics of the furnace/sample combination.13.3 Initial Adjustment of Measurement System (that is,“warm-up”)Weigh a titanium material (not necessarily atitanium reference material) to the nearest milligram, plac
41、e it ina nickel basket and transfer it to an outgassed graphite cruciblecontaining graphite powder (Note 6). Proceed as directed in14.3 and 14.4. Repeat in triplicate. (Outgassing is accom-plished automatically either as part of the continuous analysiscycle used with the automatic sample drop, or as
42、 the first stepin a two-stage cycle associated with the manual addition of thesample to the crucible.)NOTE 6In some instruments the addition of graphite powder (0.1 to1.0 g depending on crucible size and style) is designed to optimize furnaceperformance and facilitate the release of nitrogen from th
43、e test sample.Refer to the instrument manufacturers instructions for recommendedgraphite powder additions (Note 2).13.4 Determination of BlankProceed as directed in 14.3and 14.4 with a graphite crucible containing graphite powder(Note 2 and Note 6) and analyze the nickel basket but withouta sample.
44、Determine the average blank of three to fiveindividual runs (maximum allowable blank average: 0.0005 %oxygen; 0.00007 % nitrogen) and enter this value into theappropriate mechanism of the analyzer. Problems with incon-sistent or high blank values must be corrected before theanalysis can be continued
45、. If the unit does not have provisionfor automatic blank compensation, then the blank value mustbe manually subtracted from the total result prior to any othercalculation. Refer to the manufacturers instructions for properblanking procedures (Note 7).NOTE 7Typical leak checks should be 0.0 to 0.5 mm
46、 Hg. Themaximum allowable leak check is 0.7 mm Hg.13.5 StandardizationFollow the standardization proce-dure recommended by the manufacturer using titanium refer-ence materials.13.5.1 Weigh a titanium reference material to the nearestmilligram, place it in a nickel basket and transfer it to anoutgass
47、ed graphite crucible containing graphite powder ifappropriate (Note 6).13.5.2 Proceed as directed in 14.3 and 14.4.13.5.3 Repeat 13.5.1 and 13.5.2. Analyze three to fivespecimens of the titanium reference material. Calculate theaverage and standard deviation(s) of these results. Compare theaverage t
48、ot he certified value for the reference material. Adjustthe instrument output to match the certified value unless theaverage already agrees with the certified value within the rangeof the uncertainty given on the certificate.13.5.4 Confirm the standardization by analyzing anotherspecimen of the refe
49、rence material after the standardizationprocedure is complete. The result should agree with thecertified value within a suitable confidence interval (Note 8). Ifthe result agrees with the certified value within the uncertaintyprovided on the certificate of analysis, the calibration isacceptable. Also, if the certified value falls within an intervalcalculated as described in Eq 1, the calibration is acceptable.Test Result 2 t s#Certified value#Test Result 1 t s (1)where:s = standard deviation of the analyses run in 13.5.3,n = number of analyses (that
