1、BRITISH STANDARDBS ISO 22963:2008Titanium and titanium alloys Determination of oxygen Infrared method after fusion under inert gasICS 77.120.50g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37
2、g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS ISO 22963:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 May 2008 BSI 2008ISBN 978 0 580 57636 2National forewordThis British Standard is the UK implementation of ISO 22963:2008.The UK par
3、ticipation in its preparation was entrusted to Technical Committee NFE/35, Light metals and their alloys.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users ar
4、e responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsReference numberISO 22963:2008(E)INTERNATIONAL STANDARD ISO22963First edition2008-01-15Titanium and titanium alloys De
5、termination of oxygen Infrared method after fusion under inert gas Titane et alliages de titane Dosage de loxygne Mthode par infrarouge aprs fusion sous gaz inerte BS ISO 22963:2008ii iiiContents Page Foreword iv 1 Scope . 1 2 Principle. 1 3 Reagents 1 4 Apparatus 2 5 Sample . 3 6 Procedure 3 7 Prec
6、ision 6 BS ISO 22963:2008iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body intereste
7、d in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Com
8、mission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the techni
9、cal committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO sh
10、all not be held responsible for identifying any or all such patent rights. ISO 22963 was prepared by Technical Committee ISO/TC 79, Light metal and their alloys, Subcommittee SC 11, Titanium. BS ISO 22963:20081Titanium and titanium alloys Determination of oxygen Infrared method after fusion under in
11、ert gas 1 Scope This International Standard specifies an infrared method after fusion under inert gas for the determination of the mass fraction of oxygen in titanium and titanium alloys. The method is applicable to titanium and titanium alloys with a mass fraction of oxygen in the range from 0,02 %
12、 to 0,4 %. 2 Principle The test portion, plus flux (platinum or nickel metal) is fused in a graphite crucible under an inert gas stream (He or Ar) using an impulse furnace. The released oxygen combines with carbon to form carbon monoxide. Depending on the instrument design, the carbon monoxide is ox
13、idized into carbon dioxide or left as carbon monoxide and swept by the inert gas stream into an infrared detector. Infrared absorption of the carbon monoxide or dioxide is measured, against a calibration curve made of titanium standard sample. 3 Reagents 3.1 General During the analysis, unless other
14、wise stated, use only reagents of recognized analytical grade. 3.2 Magnesium perchlorate, Mg(ClO4) 2 (commercial designation: anhydrone) This is used in the instrument to absorb water. Use the purity specified by the instrument manufacturer. 3.3 Sodium hydroxide on clay (commercial designation: asca
15、rite) Used in some instruments to absorb carbon dioxide. Use purity specified by the instrument manufacturer. 3.4 Copper oxide Used in some instruments to oxidize carbon monoxide to carbon dioxide. Use the purity specified by the instrument manufacturer. 3.5 Helium or argon Use the purity and type (
16、He or Ar) specified by the instrument manufacturer. BS ISO 22963:20082 3.6 Nickel cleaning solution Mix 75 ml of acetic acid, 25 ml of nitric acid and 2 ml of hydrochloric acid. 3.7 Titanium cleaning solution 3.7.1 Titanium cleaning solution (A) Mix 100 ml of nitric acid (1+1) and 5 ml of hydrofluor
17、ic acid. 3.7.2 Titanium cleaning solution (B) Mix 90 ml of nitric acid (1+1) and 30 ml of hydrofluoric acid. 3.8 Acetone 3.9 Nickel Capsule, wire or baskets of minimum purity 99 % (mass fraction), with a mass fraction of oxygen less than 0,005 %. Nickel is immersed in the warm nickel cleaning soluti
18、on (3.6) for 30 s. Then rinse with water, ethanol, and acetone, each for 30 s, and store the nickel in acetone until used. Just before use, it should be dried with air. 3.10 Platinum Sheet (thickness 1 mm), wire ( 3 mm) or foil (thickness from 0,01 to 0,03 mm) of minimum purity 99 % (mass fraction)
19、and the mass fraction of oxygen is less than 0,005 %. Platinum is washed with acetone and stored in a desiccator until used. 3.11 Titanium standard sample Select only titanium and titanium alloy standards. Select one containing approximately from 0,2 % to 0,35 % (mass fraction) oxygen. The accuracy
20、of the test method is largely dependent upon the oxygen values assigned to the reference materials and upon the homogeneity of these materials. Thus, the titanium standard sample should be used with standard reference materials or certified reference materials. 4 Apparatus 4.1 Instrument. The instru
21、ment required for fusion of the test portion under an inert gas stream (He or Ar), using an impulse furnace and measurement of the carbon monoxide or dioxide extracted, may be obtained commercially from a number of manufacturers. 4.2 Graphite crucible, use high-purity crucibles suitable for the inst
22、rument. 4.3 Glass-wool filters. 4.4 Tweezer, made of solvent- and acid-resistant plastic (used during the sample preparation process). BS ISO 22963:200835 Sample 5.1 Sampling The sampling procedure for titanium and titanium alloys shall be agreed upon until a corresponding standard method has been p
23、ublished. 5.2 Preparation of test portions The optimum test portion is a pin (approximately 5 mm in diameter and nominally weighing from 0,06 g to 0,14 g) or a cube (of sides approximately 3 mm and nominally weighing from 0,06 g to 0,14 g). Cut off a test portion (from 0,08 g to 0,14 g) from the lab
24、oratory sample. The test portion shall be cut off by machining, using no lubricating fluid and avoiding test-portion over-heating. Clean the sample surface in accordance with method a), b) or c). a) Method a) Leach the test portion in the titanium cleaning solution (3.7.1) at about 20 C until the su
25、rface is clean. This will normally require approximately 50 s. Immediately remove the reacting test portion with tweezers and rinse it twice with water and once with ethanol and acetone, and allow to air dry. This test portion should now weigh between 0,05 g and 0,13 g. The test portion should be re
26、served in a desiccator. b) Method b) Leach the test portion in the titanium cleaning solution (3.7.2) for 5 s from the start of a violent reaction of the test portion with the solution. Immediately remove the reacting test portion with tweezers and rinse it twice with water and once with ethanol and
27、 acetone, and allow to air dry. This test portion should now weigh between 0,05 g and 0,13 g. The test portion should be reserved in a desiccator. c) Method c) File or cut off all outside edges, retaining only fresh surfaces, and finishing by rinsing with acetone and air drying. This test portion sh
28、ould now weigh between 0,05 g and 0,13 g. Weigh the test portion to the nearest 0,1 mg. 6 Procedure 6.1 Number of determinations Carry out the determination at least in duplicate and, as far as possible, under repeatability conditions. 6.2 Preparation of instrument Assemble the apparatus as recommen
29、ded by the manufacturer. Make the required power, gas and water connections. Place a graphite crucible (4.2) on the furnace pedestal and then degas by heating above the degassing temperature of the sample. Continuously heat at the oxygen-extraction temperature and record the analyzer reading signal.
30、 Repeat this operation until the stable value of the analyzer reading signal is obtained. Check that the glass-wool filters (4.3) are clean and change them as often as necessary. If the electricity supply has been switched off for a long time, allow the instrument to stabilize for the time recommend
31、ed by manufacturer. BS ISO 22963:20084 After changing the filter (4.3) and/or reagents (3.2, 3.3 and 3.4), or when the apparatus has been inoperative for a period, stabilize the instrument by carrying out trial analyses, the results of which are to be disregarded. Then proceed with blank, calibratio
32、n and preparation tests as indicated in 6.3, 6.4, and 6.5 before analyzing the sample. NOTE The appropriate degas temperature of the sample and oxygen extraction temperature are determined by the manufacturers instruction. When using devices for a computer system preparation of a working curve, stan
33、dardization (drift correction, normalization, recalibration) and measurement of the oxygen concentration shall be in accordance with the operating manual for the devices computer system software. 6.3 Blank test Prior to the determination, carry out the following blank test in duplicate. Proceed as d
34、irected in 6.5 with the graphite crucible, and analyze the nickel or platinum (same kind of metal and same mass during sample analysis) without the test portion. Obtain the reading of the blank test. The mean value of the blank test must be sufficiently low when compared to the content to be determi
35、ned in the test portion. If the blank values are abnormally high, investigate and eliminate the source of contamination. If the mean value of the blank is satisfactory, it may then be introduced into the blank subtraction device of the instrument. 6.4 Calibration Prior to the determination, carry ou
36、t the following calibration. Proceed as directed in 6.5, using a titanium standard sample (3.11) instead of the test portion. Subtract the mean of the blank value (6.3) from the analyzer reading signal. Repeat the process above several times. Calculate the intermediate oxygen equivalence factor ( f
37、) of the analyzer reading signal and calculate the oxygen equivalence factor (F) using Equations (1) and (2), iif mS=O/ (1) I ln= niifFn=1(2) BS ISO 22963:20085where F is the oxygen equivalence factor, expressed in mg, of the oxygen analyzer reading signal; f is the intermediate oxygen equivalence f
38、actor, expressed in mg, of the oxygen analyzer reading signal; mOis the mass of oxygen in the weighted titanium standard sample, expressed in mg (calculated in Equation (3); S is the intermediate analyzer reading signal after subtracting the mean value of the blank. NOTE 1 Calculate the mass of oxyg
39、en in the weighted titanium standard sample as follows: ()/mGP3O100 10= (3) where mOis the mass of oxygen in the weighted titanium standard sample, expressed in mg; G is the mass of titanium standard sample, expressed in g; P is the mass fraction of oxygen in the titanium standard sample, expressed
40、in percent. NOTE 2 Refer to the manufacturers instructions for proper blanking procedures. 6.5 Procedure Assemble the apparatus, calibrate it, and test the performance as directed in 6.2, 6.3 and 6.4. Clean the electrode with a brush and vacuum cleaner before each determination. Wrap a test portion
41、(5.2) in nickel (3.9) or platinum (3.10) and place it in the sample drop-port. NOTE The mass of nickel or platinum must exceed the mass of the test portion by at least a factor of ten. Place a graphite crucible (4.2) on the furnace pedestal and then degas by heating above the degassing temperature o
42、f the sample. Place the test portion in nickel (3.9) or platinum (3.10) in the degassed crucible, entering a test portion weight. Operate the furnace in accordance with the manufacturers instructions for fusion, extraction of oxygen and measurement of an infrared absorption. At the end of the fusion
43、 and measuring cycle, remove and discard the crucible, and record the analyzer reading signal. During the sample analysis run, the analysis of a titanium standard sample at regular intervals is recommended for monitoring drift when validating the initial calibration. BS ISO 22963:20086 6.6 Calculati
44、on The mass fraction of oxygen in the test portion, WO, expressed in a percentage, is calculated by Equation (4). ()WAAFm= 3O12100/ 10 (4) where A1is the analyzer reading signal of the sample analysis; A2is the mean value of the analyzer reading signal of the blank test; F is the oxygen equivalence
45、factor, expressed in mg, of the oxygen/analyzer reading signal; m is the mass in the test portion, expressed in g. NOTE The most modern fusion equipment gives the results directly in percent of oxygen, so that post-analysis calculations are normally not required. The difference in results of two par
46、allel determinations of the mass fraction of oxygen in the same sample shall not be greater than the tolerance Equation (5), (6) or (7). If the difference exceeds the tolerance, the analysis shall be repeated. 7 Precision The tolerance of this analytical method is expressed by the following equation
47、s: Within-laboratory-repeatability limit 2,8 0,004 8 (WO) + 0,001 5 % (mass fraction) (5) Within-laboratory-reproducibility limit 2,8 0,014 (WO) + 0,000 5 % (mass fraction) (6) Between-laboratory-reproducibility limit 2,8 0,017 1 (WO) + 0,001 % (mass fraction) (7) BS ISO 22963:2008blankBS ISO 22963:
48、2008BSI389 Chiswick High RoadLondonW4 4ALBSI British Standards InstitutionBSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter.RevisionsBritish Standards ar
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