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1、BRITISH STANDARD BS 6783-15: 1994 ISO 11433: 1993 Sampling and analysis of nickel, ferronickel and nickel alloys Part 15: Method for the determination of titanium in nickel alloys by diantipyrylmethane molecular absorption spectrometry UDC 669.245:543.422:546.22 Licensed Copy: sheffieldun sheffieldu
2、n, na, Wed Dec 06 15:08:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6783-15:1994 This British Standard, having been prepared under the direction of the Non-ferrous Metals Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 June 1994 B
3、SI 10-1999 The following BSI references relate to the work on this standard: Committee reference NFM/10 Draft for comment 92/39146 DC ISBN 0 580 23364 2 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Non-ferrous Metals Standards Policy
4、Committee (NFM/-) to Technical Committee NFM/10, upon which the following bodies were represented: Association of Bronze and Brass Founders British Non-ferrous Metals Federation British Stainless Steel Association British Steel Industry Department of Trade and Industry (Laboratory of the Government
5、Chemist) Engineering Equipment and Materials Users Association Institute of British Foundrymen London Metal Exchange Ministry of Defence Nickel Development Institute Non-ferrous Metal Stockists Steel Casting Research and Trade Association Coopted members Amendments issued since publication Amd. No.D
6、ateComments Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:08:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6783-15:1994 BSI 10-1999i Contents Page Committees responsibleInside front cover National forewordii 1Scope1 2Normative references1 3Principle1 4Reagents1 5Apparatus1 6Sampling a
7、nd sample preparation2 7Procedure2 8Expression of results3 9Interferences3 10Test report4 Table 1 Mass of sample to be taken2 Table 2 Nominal composition of test samples4 Table 3 Results of statistical analysis4 List of referencesInside back cover Licensed Copy: sheffieldun sheffieldun, na, Wed Dec
8、06 15:08:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6783-15:1994 ii BSI 10-1999 National foreword This Part of BS 6783 has been prepared under the direction of the Non-ferrous Metals Standards Policy Committee. It is identical with ISO 11433:1993 Nickel alloys Determination of titanium content
9、 Diantipyrylmethane molecular absorption spectrometric method, published by the International Organization for Standardization (ISO). At present this British Standard consists of 15 Parts all concerned with analysis of nickel, ferronickel and nickel alloys. Further International Standards are in pre
10、paration on sampling and analysis of nickel, ferronickel and nickel alloys and, when available, these will be published as further Parts of this British Standard. The Technical Committee has reviewed the provisions of ISO 385-1 and ISO 648, to which normative reference is made in the text, and has d
11、ecided that they are acceptable for use in conjunction with this standard. ISO 385-1 is related to BS 846:1985 Specification for burettes and ISO 648 is related to BS 1583:1986 Specification for one-mark pipettes. A British Standard does not purport to include all the necessary provisions of a contr
12、act. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International StandardCorresponding British Standard ISO 1042:1983BS 1792:1982 Specification for one-mark volu
13、metric flasks (Identical) ISO 5725:1986BS 5497 Precision of test methods Part 1:1987 Guide for the determination of repeatability and reproducibility for a standard test method by inter-laboratory tests (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages
14、i and ii, pages 1 to 4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:08:44 GMT+00
15、:00 2006, Uncontrolled Copy, (c) BSI BS 6783-15:1994 BSI 10-19991 1 Scope This International Standard specifies a molecular absorption spectrometric method for the determination of titanium in the range of 0,3 % (m/m) to 5,0 % (m/m) in nickel alloys. Evidence exists that extension of this method is
16、possible for titanium contents down to 0,05 % (m/m). Modifications in the general method allow the determination of titanium in alloys containing tungsten and/or tantalum. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions o
17、f this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indi
18、cated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 385-1:1984, Laboratory glassware Burettes Part 1: General requirements. ISO 648:1977, Laboratory glassware One-mark pipettes. ISO 1042:1983, Laboratory glassware One-mark volumetric flasks. ISO 572
19、5:1986, Precision of test methods Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests. 3 Principle Dissolution of a test portion in hydrochloric and nitric acids. Removal of hydrochloric acid and nitric acid by evaporation to fumes in the presence
20、of sulfuric acid. Formation of the titanium diantipyrylmethane complex and measurement of the absorbance of the test solution at a wavelength of 390 nm. 4 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equi
21、valent purity. 4.1 Hydrochloric acid, 20 = 1,18 g/ml. 4.2 Hydrochloric acid, 20 = 1,18 g/ml, diluted 1 + 1. 4.3 Sulfuric acid, 20 = 1,84 g/ml, diluted 1 + 1. Slowly, and with constant stirring, add 100 ml of sulfuric acid to 100 ml of water. 4.4 Nitric acid, 20 = 1,41 g/ml. 4.5 Ammonium hydroxide, s
22、olution 20 = 0,88 g/ml. 4.6 Potassium hydrogen sulfate (KHSO4). 4.7 Ascorbic acid, solution. Dissolve 20 g of ascorbic acid (C6H8O6) in water, dilute to 200 ml and mix. 4.8 Oxalic acid, solution. Dissolve 10 g of oxalic acid dihydrate (COOH)2.2H2O in water, dilute to 200 ml and mix. 4.9 Diantipyrylm
23、ethane, solution Dissolve 4g of diantipyrylmethane monohydrate (C23H24N4O2.H2O) in water containing 25 ml of the hydrochloric acid (4.2), dilute to 200 ml and mix. 4.10 Sodium chloride, solution. Dissolve 117 g of sodium chloride (NaCl) in water, dilute to 500 ml and mix. 4.11 Titanium, standard ref
24、erence solution (0,200 g/l). Dissolve 0,739 g of potassium titanyl oxalate dihydrate K2TiO(C2O4)2.2H2O in water. Add 50 ml of the dilute sulfuric acid (4.3) and evaporate to heavy fumes. Cool and dilute with water. Transfer the cold solution to a 500 ml one-mark volumetric flask, make up to the mark
25、 with water and mix. 4.12 Titanium, standard solution (25 mg/l). Transfer 25,0 ml of the titanium standard reference solution (4.11) to a 200 ml one-mark volumetric flask. Add 20 ml of the dilute sulfuric acid (4.3). Cool the solution, make up to the mark with water and mix. 5 Apparatus Ordinary lab
26、oratory apparatus and 5.1 Unetched conical beakers, of capacity 125 ml. 5.2 Volumetric flasks, of capacities 50 ml, 100 ml, 200 ml, 250 ml and 500 ml, in accordance with ISO 1042, Class A. 5.3 Pipette, of capacity 5 ml, in accordance with ISO 648, Class A. 5.4 Microburette, of capacity 10 ml, gradua
27、ted in divisions of 0,02 ml, in accordance with ISO 385-1, Class A. 5.5 Molecular absorption spectrometer, capable of measuring absorbance at a wavelength of 390 nm. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:08:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6783-15:1994 2 BSI 10-19
28、99 6 Sampling and sample preparation 6.1 Sampling and preparation of the laboratory sample shall be carried out by normal agreed procedures or, in the case of dispute, according to the relevant International Standard. 6.2 The laboratory sample is normally in the form of millings or drillings and no
29、further preparation of the sample is necessary. 6.3 If it is suspected that the laboratory sample is contaminated with oil or grease from the milling or drilling process, it shall be cleaned by washing with high-purity acetone and dried in air. 6.4 If the laboratory sample contains particles or piec
30、es of widely varying sizes, the test sample should be obtained by riffling. 7 Procedure 7.1 Preparation of test solution 7.1.1 Test portion Weigh, to the nearest 0,1 mg, a test portion of the sample according to Table 1. Table 1 Mass of sample to be taken 7.1.2 Dissolution of a test portion in acid
31、Transfer the test portion to the 125 ml conical beaker (5.1). Add 10 ml of the hydrochloric acid (4.1) and 3 ml of the nitric acid (4.4). Apply sufficient heat to initiate and maintain the reaction until dissolution is complete. If the alloy resists dissolution, some adjustment of the acid mixture m
32、ay be required. Add hydrochloric acid (4.1) in 1 ml increments and continue heating to dissolve the test portion. 7.1.3 Preparation of the final test solution Add 7 ml of the dilute sulfuric acid (4.3) and evaporate the solution until heavy white fumes appear. Cool the contents and proceed as direct
33、ed in 7.1.3.1 or 7.1.3.2, depending on whether tantalum is present or not. 7.1.3.1 In the absence of tantalum add 20 ml of the oxalic acid solution (4.8) and heat to dissolve the salts. Cool the solution and, in tungsten-free alloys, proceed as directed in 7.1.4. 7.1.3.1.1 If the alloy contains tung
34、sten, add sufficient ammonium hydroxide solution (4.5) to make the solution alkaline. Boil the solution until the tungstic acid is dissolved. Cool the solution and reacidify by adding 20 ml of the hydrochloric acid (4.1). Cool the solution and proceed as directed in 7.1.4. 7.1.3.2 In the presence of
35、 tantalum add 30 ml of water, heat to dissolve the salts and cool again. Filter the solution through a tightly packed filter pulp pad. Wash the precipitate with warm water. Retain the filtrate. Transfer the pad and precipitate to a platinum crucible. Ignite at 800 C and cool. Add 1 g of the potassiu
36、m hydrogen sulfate (4.6), cover the crucible with a platinum lid, and fuse carefully over a flame. Cool and transfer the crucible to a 150 ml beaker containing 20 ml of the oxalic acid solution (4.8). Heat carefully until the melt is dissolved. Wash and remove the platinum crucible. Combine the oxal
37、ate solution with the original filtrate and proceed as directed in 7.1.4. 7.1.4 Dilutions 7.1.4.1 Dilution for less than 1 % (m/m) titanium Transfer the test solution (7.1.3.1 or 7.1.3.1.1 or 7.1.3.2) to a 100 ml one-mark volumetric flask (5.2), make up to the mark with water and mix. 7.1.4.2 Diluti
38、on for 1 % (m/m) to 5 % (m/m) titanium Transfer the test solution (7.1.3.1 or 7.1.3.1.1 or 7.1.3.2) to a 250 ml one-mark volumetric flask (5.2), make up to the mark with water and mix. 7.2 Colour development 7.2.1 Using a pipette (5.3), transfer 5,0 ml aliquots of the test solution (7.1.4.1 or 7.1.4
39、.2) to each of two 50 ml one-mark volumetric flasks (5.2). 7.2.2 Add 5,0 ml of the dilute hydrochloric acid (4.2), 5,0 ml of the ascorbic acid solution (4.7) and 20,0 ml of the sodium chloride solution (4.10) to both volumetric flasks. Mix the solutions and allow to stand for a few minutes. 7.2.3 Ad
40、d 10,0 ml of the diantipyrylmethane solution (4.9) to one of the volumetric flasks. 7.2.4 Make up the solutions in both flasks (7.2.2 and 7.2.3) to the marks with water, mix and allow to stand for 40 min. Expected titanium content Mass of sample % (m/m)g 0,3 to 3,00,19 to 0,21 3,0 to 5,00,099 to 0,1
41、1 Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:08:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6783-15:1994 BSI 10-19993 7.3 Spectrometric measurement 7.3.1 Using 1 cm cells, measure the absorbance of tooth solutions in 7.2.4 against water as the reference, at a wavelength of 390 nm
42、 with the molecular absorption spectrometer (5.5). 7.3.2 Subtract the background absorbance of the test solution from the absorbance of the test solution containing the diantipyrylmethane complex. 7.4 Blank test Carry out a blank test in parallel with the determination, following the same procedure
43、and using the same quantities of all the reagents. 7.5 Calibration 7.5.1 Using a microburette (5.4), transfer 0 ml, 1,0 ml, 2,0 ml, 3,0 ml, 4,0 ml and 5,0 ml of the titanium standard solution (4.12) to a series of 50 ml one-mark volumetric flasks. 7.5.2 Add the dilute hydrochloric acid, ascorbic aci
44、d and sodium chloride solutions as described in 7.2.2. 7.5.3 Add 10,0 ml of the diantipyrylmethane solution (4.9) to the solutions. Dilute the solutions to the marks with water and mix. Allow to stand for 40 min. This series corresponds to 0 4g, 0,5 4g, 1,0 4g, 1,5 4g, 2,0 4g and 2,5 4g of titanium
45、per millilitre. 7.5.4 Measure the absorbance of the calibration solutions as described in 7.3. Subtract the measured absorbance of the 0 4g/ml calibration solution from the absorbance values of the remaining calibration solutions. 7.5.5 Plot the corrected absorbance values against the respective con
46、centrations of titanium, in micrograms per millilitre, in the calibration solutions. 7.6 Number of determinations Carry out the determination at least in duplicate. 7.7 Check test The performance of the method may be checked by analysing, in parallel with the determination and following the same pro
47、cedure, one or more samples of the same alloy type whose titanium content is known. 8 Expression of results 8.1 Calculation 8.1.1 Determine the concentration of titanium in the test solution (see 7.3.2), and in the blank test (7.4) by means of the calibration graph (7.5.5). 8.1.2 Calculate the titan
48、ium content wTi, expressed as a percentage by mass, of the test portion using the formula where 8.2 Precision 8.2.1 Laboratory tests Eleven laboratories in four countries participated in the testing of this procedure using four samples of nominal composition given in Table 2. Each sample was analyse
49、d in duplicate on different days. 8.2.2 Statistical analysis 8.2.2.1 Results from the interlaboratory test programme were evaluated according to ISO 5725, using the means of the duplicate results. The data were tested for statistical outliers by the Cochran and Dixon tests given in ISO 5725. 8.2.2.2 The principle of the Cochran test is that a set of results is an outlier if the within-laboratory variance is too large in relation to others. Dixons test is to determine if the mean from laboratory is too far from the other laboratory means. Both tes