1、 Reference number ISO/TS 13899-3:2005(E) ISO 2005TECHNICAL SPECIFICATION ISO/TS 13899-3 First edition 2005-02-15 Steel Determination of Mo, Nb and W contents in alloyed steel Inductively coupled plasma atomic emission spectrometric method Part 3: Determination of W content Aciers Dosage du Mo, du Nb
2、 et du W dans les aciers allis Mthode par spectromtrie dmission atomique avec plasma induit par haute frquence Partie 3: Dosage du W ISO/TS 13899-3:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but
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7、rg Web www.iso.org Published in Switzerland ii ISO 2005 All rights reservedISO/TS 13899-3:2005(E) ISO 2005 All rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references. 1 3 Principle. 1 4 Reagents 2 5 Apparatus 3 6 Sampling and samples. 4 7 Procedure 4 7.1 Preparation of test so
8、lution, T n . 4 7.2 Preparation for spectrometric measurements. 5 7.3 Pre-analysis of the test solution 5 7.4 Preparation of calibration solutions for bracketing, K Lnand K Hn6 7.5 Analysis of test solutions 6 8 Expression of results 6 8.1 Method of calculation . 6 8.2 Precision 6 9 Test report. 7 A
9、nnex A (normative) Procedure for the determination of instrumental criteria 8 Annex B (informative) Additional information on the international collaborative trial . 10 Annex C (informative) Graphical representation of precision data. 12 ISO/TS 13899-3:2005(E) iv ISO 2005 All rights reservedForeword
10、 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 interested in a subject for which a technical
11、 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 Commission (IEC) on all matters of elec
12、trotechnical 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 technical committees are circulated to the
13、 member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. In other circumstances, particularly when there is an urgent market requirement for such documents, a technical committee may decide to publish other types of n
14、ormative document: an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in an ISO working group and is accepted for publication if it is approved by more than 50 % of the members of the parent committee casting a vote; an ISO Technical Specification (IS
15、O/TS) represents an agreement between the members of a technical committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting a vote. An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a further three y
16、ears, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an International Standard or be withdrawn. Attention is drawn to the possibility that some of the
17、 elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TS 13899-3 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 1, Methods of determination of chemical composition. ISO/TS 13899 cons
18、ists of the following parts, under the general title Steel Determination of Mo, Nb and W contents in alloyed steel Inductively coupled plasma atomic emission spectrometric method: Part 1: Detemination of Mo content Part 2: Detemination of Nb content Part 3: Detemination of W content TECHNICAL SPECIF
19、ICATION ISO/TS 13899-3:2005(E) ISO 2005 All rights reserved 1Steel Determination of Mo, Nb and W contents in alloyed steel Inductively coupled plasma atomic emission spectrometric method Part 3: Determination of W content 1 Scope This Technical Specification specifies a method for the determination
20、of tungsten content in steel by means of inductively coupled plasma atomic emission spectrometry. This method is applicable to tungsten contents between 0,1 % and 20 % (mass fraction). 2 Normative references The following referenced documents are indispensable for the application of this document. F
21、or dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 648:1977, Laboratory glassware One-mark pipettes ISO 1042:1998, Laboratory glassware One-mark volumetric flasks ISO 3696:1987, Water for
22、analytical laboratory use Specification and test methods ISO 5725-1:1994, Accuracy (trueness and precision) of measurement methods and results Part 1: General principles and definitions ISO 5725-2:1994, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the
23、 determination of repeatability and reproducibility of a standard measurement method ISO 5725-3:1994, Accuracy (trueness and precision) of measurement methods and results Part 3: Intermediate measures of the precision of a standard measurement method ISO 14284:1996, Steel and iron Sampling and prepa
24、ration of samples for the determination of chemical composition 3 Principle The sample is dissolved in a hydrochloric, nitric and hydrofluoric acid mixture and fumed with a phosphoric and perchloric acid mixture. Hydrofluoric acid and an internal standard element (if used) are added and the solution
25、 is diluted to known volume. The solution is filtered and nebulized into an inductively coupled plasma (ICP) spectrometer and the intensity of the emitted light from the element is measured simultaneously with the light emitted from the internal standard element. ISO/TS 13899-3:2005(E) 2 ISO 2005 Al
26、l rights reservedThe method uses a calibration based on close matrix matching of the calibration solutions to the sample and close bracketing of the tungsten content around the approximate concentration of tungsten in the sample to be analysed. This compensates for matrix interferences and provides
27、high accuracy, even in highly alloyed steels where spectral interferences can be severe. Nonetheless, all interferences shall be kept to a minimum and it is therefore essential that the spectrometer used meets the performance criteria specified in the method for the selected analytical lines. In ord
28、er to accurately matrix match, it is necessary to know the content of all elements in the sample (to the nearest %). To this end, it may be necessary to carry out a preliminary analysis of the sample by a semi-quantitative method. 4 Reagents During the analysis, unless otherwise stated, use only rea
29、gents of recognised analytical grade and only grade 2 water as specified in ISO 3696. 4.1 Hydrofluoric acid, HF, 40 % (mass fraction), approximately 1,14 g/ml 4.2 Hydrochloric acid, HCl, approximately 1,19 g/ml 4.3 Nitric acid, HNO 3 , approximately 1,40 g/ml 4.4 Phosphoric acid, H 3 PO 4 , approxim
30、ately 1,70 g/ml, diluted 1 + 1 4.5 Perchloric acid, HClO 4 , approximately 1,54 g/ml, diluted 1 + 1 4.6 Fuming acid mixture: mix 100 ml of the phosphoric acid (4.4) and 300 ml of the perchloric acid (4.5) 4.7 Internal standard solution, 1 000 mg/l Choose a suitable element to be added as internal st
31、andard and prepare a 1 000 mg/l solution. The internal standard chosen shall be pure, shall not be present in the sample, and shall not interfere with analytical wavelengths, nor should the internal standard element wavelength be interfered with by elements in the test solution. The internal standar
32、d shall be soluble in the acids used and it shall not cause precipitation. Moreover, the excitation conditions of the analytical line and the internal standard element line should match. 4.8 Tungsten stock standard solution, 1 000 mg/l Weigh, to the nearest 0,001 g, 0,5 g of high purity tungsten min
33、imum 99,95 % (mass fraction) and dissolve in a mixture of 10 ml hydrofluoric acid (4.1) and 20 ml nitric acid (4.3). Cool and transfer the solution quantitatively to a calibrated 500 ml one-mark plastic volumetric flask. Dilute to the mark with water and mix. 1 ml of this solution contains 1 mg of W
34、. It is not permitted to use pre-prepared tungsten standard solutions supplied by second parties. 4.9 Tungsten standard solution, 100 mg/l Transfer, with a calibrated micropipette, 25 ml of the tungsten stock standard solution (4.8) into a calibrated 250 ml one-mark plastic volumetric flask. Add 5 m
35、l of hydrofluoric acid (4.1) and 10 ml of nitric acid (4.3). Dilute to the mark with water and mix. 1 ml of this solution contains 0,1 mg of W. ISO/TS 13899-3:2005(E) ISO 2005 All rights reserved 3NOTE If calibrated micropipettes of suitable volume are not available it would be more advantageous to
36、use more concentrated standard solutions. These solutions must, however, be prepared for each series of analysis, in order to avoid possible precipitation. 4.10 Standard solutions of interfering and matrix elements Prepare standard solutions for each element of which more than 1 % (mass fraction) is
37、 contained in the test sample. Use pure elements or oxides with tungsten contents less than 10 g/g. Commercial certified standard solutions can also be used if the tungsten content is less than the value specified above. NOTE If a large amount of an element is to be added (e.g. iron), it might be mo
38、re advantageous to use the pure metal and weigh the correct amount (see 7.3 and 7.4). In this case, use the dissolution procedure described in 7.1.2. 5 Apparatus The plastic pipettes and flasks to be used shall be calibrated in accordance with ISO 648 or ISO 1042, as appropriate. Ordinary laboratory
39、 apparatus and 5.1 Atomic emission spectrometer, equipped with an inductively coupled plasma (ICP) and a nebulization system resistant to hydrofluoric acid. When a polytetrafluoroethylene (PTFE) nebulizer is used, it is recommended that a surface active agent should be added to improve wetting in th
40、e nebulizer and spray chamber. Modern nebulizers are, however, often manufactured of plastic materials with better wetting-characteristics than PTFE and can therefore (as is the case with sapphire nebulizers) be used without a surface active agent. The ICP-ES spectrometer used will be satisfactory i
41、f, after optimising according to 7.2.1 to 7.2.4, it meets the performance criteria given in 5.1.2 to 5.1.4. The spectrometer can be either the simultaneous or the sequential type. A sequential type can be used either with or without an internal standard. However, if a sequential spectrometer is to b
42、e used with an internal standard, it shall be fitted with an arrangement which allows for the simultaneous measurement of the internal standard line. 5.1.1 Analytical lines This standard does not specify any particular emission line. It is mandatory that each laboratory carefully investigates the li
43、ne/lines available on its own equipment to find the most suitable one regarding sensitivity and freedom from interferences. In Table 1, however, a suggestion is given together with possible interferences. The line for the internal standard element should be selected according to 4.7. Table 1 Example
44、 of analytical line and lines for internal standard element Wavelength Element nm Possible interferences W 207,91 Cr, V, Mo Sr (as internal standard) 407,77 Sc (as internal standard) 363,07 Cd (as internal standard) 214,44 ISO/TS 13899-3:2005(E) 4 ISO 2005 All rights reserved5.1.2 Minimum practical
45、resolution of the spectrometer Calculate the bandwidth, according to Clause A.1, for the wavelength used including the line for internal standard. The bandwidth shall be less than 0,030 nm. 5.1.3 Minimum short-term precision Calculate the short-term precision according to Clause A.2. The relative st
46、andard deviation shall not exceed 0,5 % of the mean absolute or ratioed intensities for concentrations 100 to 1 000 times the LOD (5.1.4) mg/l. For concentrations 10 to 100 times the LOD the RSD shall not exceed 5 %. 5.1.4 Limit of Detection (LOD) and Limit of Quantification (LOQ) Calculate the LOD
47、and LOQ, according to Clause A.3, for the analytical line used. The values shall be below the values in Table 2. Table 2 Limit of Detection (LOD) and Limit of Quantification (LOQ) LOD LOQ Element mg/l mg/l W 1 5 5.2 Polytetrafluoroethylene (PTFE) beakers 5.3 100 ml polypropylene volumetric flasks 6
48、Sampling and samples Sampling and preparation of the laboratory sample shall be carried out in accordance with ISO 14284 or appropriate national standards for steel. 7 Procedure 7.1 Preparation of test solution, T n7.1.1 Weigh, to the nearest 0,000 5 g, a test portion of the laboratory sample in acc
49、ordance with Table 3, and transfer it to a PTFE beaker. Table 3 Test portion Expected content Test portion % (mass fraction) g 0,1 to 5 0,5 5 to 20 0,1 7.1.2 Add 10 ml of HCl (4.2), 2 ml of HNO 3(4.3) and 5 ml of HF (4.1). Heat to complete dissolution. Make sure that all deposits that may have formed on the walls of the beaker are washed down using a glass stick with a rubber head. Add 20 ml of fuming acid mixture (4.6) and heat until the perchloric acid starts to fume. Continue to
