1、Designation: E 1409 08Standard 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of oxygen intitanium and titanium alloy
3、s in concentrations from 0.01 % to0.5 % 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 onl
4、y.1.3 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 war
5、ningstatements 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 Pract
6、ice for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals3E 882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE 1019 Test Methods for Determination of Carbon, Sulfur,Nitrogen, and Oxygen in Steel and in Iron, Nickel, andCobalt AlloysE 1601
7、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 thismethod, refer to Terminolo
8、gy E 135 and Practice E 1914.4. 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
9、test sample, plus flux, is fused in a graphite crucibleunder a flowing inert gas stream (argon, helium) at a tempera-ture sufficient to release oxygen and nitrogen. Oxygen com-bines with carbon to form carbon monoxide (CO) and nitrogenis released as N2. Depending on instrument design, the CO isoxidi
10、zed to carbon dioxide (CO2) or left as CO and swept bythe inert gas stream into either an infrared or thermal conduc-tivity detector. The detector output is compared to that ofreference materials and the result is displayed as percentoxygen. The nitrogen is swept by the inert gas stream (heliumgas)
11、into a thermal conductivity detector. The detector responseis compared to that of reference materials and the result isdisplayed 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 conv
12、erts CO to CO2and hydrogen (H2)to water (H2O). The CO2is absorbed on sodium hydroxideimpregnated on clay, and the H2O is removed with magnesiumperchlorate. The nitrogen, as N2, enters the measuring cell andthe thermistor bridge output is integrated and processed todisplay percent oxygen.5. Significa
13、nce and Use5.1 This test method is primarily intended as a test forcompliance with compositional specifications. It is assumedthat all who use this test method will be trained analysts1E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and is thedirect responsibility of Subcommittee
14、E01.06 on Ti, Zr, W, Mo, Ta, Nb, Hf, Re.Current edition approved June 15, 2008. Published July 2008. Originallyapproved in 1991. Last previous edition approved in 2005 as E 1409 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.or
15、g. 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 Box C700, West Conshohocken, PA 19428-2959, United States.capable of performing common laboratory procedures ski
16、ll-fully and safely. It is expected that the work will be performedin a properly equipped laboratory.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.
17、7. Apparatus7.1 InstrumentFusion and measurement 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 purificationsys
18、tems (Note 1).NOTE 1The apparatus and analysis 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. Consu
19、lt the instrument manufacturers instruction 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
20、 requirements of the auto-matic sample drop, 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 Twee
21、zersSix-inch tweezers made of solvent and acid-resistant plastic.8. Reagents8.1 AcetoneResidue after evaporation must be0.0005 %.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 Perc
22、hlorate, Anhydrous4Used in the in-strument 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 nitric acid(HNO3), and 2 mL of hydrochloric acid (HCl).8.6 Rare Earth/Copper OxideRe
23、agent used in some in-struments to oxidize CO to CO2for thermal conductivitydetection. 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
24、SolutionPrepare a fresh solu-tion of 3 parts 30 % hydrogen peroxide (H2O2) and 1 part 48 %hydrofluoric acid (HF). HNO3may be substituted for 30 %H2O2(see Note 3). (WarningHF causes serious burns thatmay not be immediately painful; refer to the paragraph aboutHF in the Safety Precautions Section of P
25、ractices E50.)NOTE 3In 2004, alternative sample preparation procedures (Section12) were tested by seven laboratories. Three laboratories processed thesample materials by picking their samples in HF-H2O2(8.8). Two labo-ratories utilized the HF-HNO3alternative pickle solution (8.8). Twolaboratories ut
26、ilized abrasion (in this case diamond saw and shear) inaccordance with 12.4. The prepared samples were distributed among thelaboratories for analysis. Six laboratories analyzed these samples inrandom order under a single operator, single-day, single calibration samplerun. The results of this testing
27、 are given in Tables X1.1 and X2.1 foroxygen and nitrogen, respectively. In both cases, the analysis of theANOVA indicates 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 cru
28、cibles and operatingfurnaces to avoid personal injury by either burn or electricalshock.9.2 For precautions to be observed 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
29、the required power, gas, and water connections.Turn on the instrument and allow sufficient time to stabilize theequipment.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
30、14.3and 14.4 to condition the newly changed filters before attempt-ing to calibrate the system or to determine the value 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 nickelwire baskets that
31、must be removed before use.11.2 Immerse the flux in nickel flux cleaning solution for 50s to 60 s, then rinse in running water for 2 min to 3 min. Pourflux onto paper towels to remove excess water. Place flux insealable glass container, rinse with acetone and decant. Re-place with fresh acetone and
32、store flux under acetone untilused. (See Notes 4 and 5.)NOTE 4Nickel is necessary to flux the titanium fusion reaction butsignificant oxidation can be present on the surface of nickel wire basketsthat can cause interference with the analysis. Ultra high-purity nickelbaskets are commercially availabl
33、e that do not require the nickel cleaningprocedure above. Their sufficiency must be verified by satisfactory blankdeterminations.NOTE 5The fluxing agent must be of proper size to be introducedthrough the sample drop mechanism and into the graphite crucible.4Known commercially as Anhydrone.5Known com
34、mercially as Ascarite II.E140908212. Sample Preparation12.1 The optimum test sample is a pin approximately18 in.(5 mm) in diameter and nominally weighing 0.12 g to 0.15 g.Cut the sample to this approximate weight range.12.2 Leach the test sample in the titanium sample picklesolution (WarningSee 8.8.
35、) (see Note 4) until the surface isclean. This will normally require approximately 5 s from thetime of the initial vigorous 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 dr
36、y. This test sample should now weighbetween 0.100 g and 0.140 g.12.4 Alternatively, clean surfaces may be prepared on thetest 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
37、 0.100 gand 0.140 g.12.5 All subsequent operations on the test sample and fluxmust be done without introducing contamination 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 aceton
38、e and air dry beforeanalysis.13. Standardization13.1 StandardantsSelect only titanium or titanium alloyreference materials. Select 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 t
39、he oxygen and nitrogen concentrations of thereference materials, as well as upon their homogeneity. Thus,wherever possible, reference materials used to confirm instru-ment standardization should be National Institute of Standardsand Technology (NIST) Standard Reference Materials or othercertified re
40、ference 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 verified by stan-dardization with titanium reference materials because of thefusion characteristics of the furnace/sample combina
41、tion.13.3 Initial Adjustment of Measurement System (that is,“warm-up”)Weigh a titanium material (not necessarily atitanium reference material) to the nearest milligram, place it ina nickel basket and transfer it to an outgassed graphite cruciblecontaining graphite powder (Note 6). Proceed as directe
42、d 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 the first stepin a two-stage cycle associated with the manual addition of thesample to the crucible.)NOTE 6In some instruments
43、 the addition of graphite powder (0.1 g to1.0 g depending on crucible size and style) is designed to optimize furnaceperformance and facilitate the release of nitrogen from the test sample.Refer to the instrument manufacturers instructions for recommendedgraphite powder additions (Note 2).13.4 Deter
44、mination 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. Determine the average blank of three to fiveindividual runs (maximum allowable blank average: 0.0005 %oxygen; 0.00007 % nitro
45、gen) 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. If the unit does not have provisionfor automatic blank compensation, then the blank value mustbe manually subtracted from t
46、he total result prior to any othercalculation. Refer to the manufacturers instructions for properblanking procedures (Note 7).NOTE 7Typical leak checks should be 0.0 mm Hg to 0.5 mm Hg. Themaximum allowable leak check is 0.7 mm Hg.13.5 StandardizationFollow the standardization proce-dure recommended
47、 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 anoutgassed graphite crucible containing graphite powder ifappropriate (Note 6).13.5.2 Proceed as directed in 14.3 and 14.4.13.5
48、.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 to the certified value for the reference material. Adjustthe instrument output to match the certified value unless theav
49、erage 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 reference 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
