BS-7455-3-1991 ISO-7530-3-1990.pdf

BRITISH STANDARD BS 7455-3: 1991 ISO 7530-3: 1990 Analysis of nickel alloys by flame atomic absorption spectrometry Part 3: Method for the determination of chromium Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:59:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7455-3:1991 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 28 June 1991 © BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference NFM/10 Draft for comment 89/47726 DC ISBN 0 580 19777 8 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Non-ferrous Metals Standards Policy Committee (NFM/-) to Technical Committee NFM/10, upon which the following bodies were represented: British Non-ferrous Metals Federation British Steel Industry Department of Trade and Industry (Laboratory of the Government Chemist) Engineering Equipment and Materials Users Association Ministry of Defence Nickel Development Institute Non-ferrous Metal Stockists Process Plant Association Stainless Steel Fabricators Association of Great Britain Coopted members Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:59:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7455-3:1991 © BSI 11-1999i Contents Page Committees responsibleInside front cover National forewordii 1Scope1 2Normative references1 3Principle1 4Reagents1 5Apparatus1 6Sampling and sample preparation1 7Procedure1 8Expression of results2 9Test report2 Table 1 Nominal composition of test samples2 Table 2 Results of statistical analysis2 Publication(s) referred toInside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:59:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7455-3:1991 ii © BSI 11-1999 National foreword This Part of BS 7455 has been prepared under the direction of the Non-ferrous Metals Standards Policy Committee. It is identical with ISO 7530-3 “Nickel alloys Flame atomic absorption spectrometric analysis Part 3:1990 Determination of chromium content”, published by the International Organization for Standardization (ISO). At present this British Standard consists of six Parts all concerned with methods for flame spectrometric analysis of nickel alloys. Further International Standards are in preparation on the same subject and when available, these will be published as further Parts of this British Standard. A British Standard does not purport to include all the necessary provisions of a contract. 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 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) ISO 7530-1:1990BS 7455 Analysis of nickel alloys by flame atomic absorption spectrometry Part 1:1991 General requirements and sample dissolution (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 and 2, 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: London South Bank University, London South Bank University, Fri Dec 08 13:59:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7455-3:1991 © BSI 11-19991 1 Scope This part of ISO 7530 specifies a flame atomic absorption spectrometric method for the determination of chromium in the range of 0,01 % (m/m) to 4 % (m/m) in nickel alloys. Typical compositions of some nickel alloys are given in ISO 7530-1, Annex B. The general requirements concerning the apparatus, sampling, dissolution of the test sample, atomic absorption measurements, calculations and test report are given in ISO 7530-1. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 7530. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO 7530 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 5725:1986, Precision of test methods Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests. ISO 7530-1: , Nickel alloys Flame atomic absorption spectrometric analysis Part 1: General requirements and sample dissolution1). 3 Principle Dissolution of a test portion in acid and aspiration of the test solution into a nitrous oxide-acetylene flame of an atomic absorption spectrometer. Measurement of the absorbance of the resonance line energy from the spectrum of chromium and comparison with that of calibration solutions at a wavelength of 357,9 nm. 4 Reagents In addition to the reagents listed in ISO 7530-1, the following special reagents are required. 4.1 Strontium chloride, solution. Transfer 113,5 g of strontium chloride hexahydrate (SrCl2·6H2O) to a 600 ml beaker, dissolve in 400 ml of hot water (50 °C to 60 °C), cool and transfer to a 1 000 ml one-mark volumetric flask. Make up to the mark with water and mix. The strontium chloride should be free of heavy metals. 4.2 Chromium, standard reference solution (1,000 g/l). Weigh, to the nearest 0,001 g, 1,000 g of chromium metal of 99,9 % (m/m) minimum purity and transfer to a 400 ml beaker. Add 30 ml of hydrochloric acid (Ô20= 1,18 g/ml) diluted 1 + 1 and heat to complete dissolution. Cool, transfer to a 1 000 ml one-mark volumetric flask and add 35 ml of hydrochloric acid (Ô20= 1,18 g/ml). Make up to the mark with water, mix and store in a polyethylene bottle. 4.3 Chromium, standard solution (50 mg/l). Pipette 50 ml of the chromium standard reference solution (4.2) into a 1 000 ml one-mark volumetric flask and add 50 ml of hydrochloric acid (Ô20= 1,18 g/ml). Make up to the mark with water, mix and store in a polyethylene bottle. 5 Apparatus The apparatus required is specified in clause 5 of ISO 7530-1. 6 Sampling and sample preparation Refer to clause 6 of ISO 7530-1. 7 Procedure 7.1 Preparation of test solution Proceed as directed in 7.1.1 to 7.1.4 of ISO 7530-1. 7.1.1 Primary dilutions 7.1.1.1 Initial dilution for 0,01 % (m/m) to 0,10 % (m/m) chromium Transfer the test solution (7.1) to a 100 ml one-mark volumetric flask. Add 4 ml of strontium chloride solution (4.1). Make up to the mark with water and mix. Remove any products of hydrolysis by settlement and dry filtration or by centrifuging. 7.1.1.2 Initial dilution for 0,1 % (m/m) to 4,0 % (m/m) chromium Transfer the test solution (7.1) to a 500 ml one-mark volumetric flask. Add 20 ml of hydrochloric acid (Ô20= 1,18 g/ml). Make up to the mark with water and mix. Remove any products of hydrolysis by settlement and dry filtration or by centrifuging. 1) To be published. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:59:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7455-3:1991 2 © BSI 11-1999 7.1.2 Secondary dilutions 7.1.2.1 Secondary dilution for 0,1 % (m/m) to 0,8 % (m/m) chromium Pipette 50 ml of the solution from 7.1.1.2 into a 100 ml one-mark volumetric flask. Add 4 ml of strontium chloride solution (4.1) and 3 ml of hydrochloric acid (Ô20= 1,18 g/ml). Make up to the mark with water and mix. 7.1.2.2 Secondary dilution for 0,4 % (m/m) to 4 % (m/m) chromium Pipette 10 ml of the solution from 7.1.1.2 into a 100 ml one-mark volumetric flask. Add 4 ml of strontium chloride solution (4.1) and 5 ml of hydrochloric acid (Ô20= 1,18 g/ml). Make up to the mark with water and mix. 7.2 Reagent blank solution Carry out a blank test in parallel with the determination, following the same procedure and using the same quantities of all the reagents. 7.3 Chromium calibration solutions Using pipettes, transfer to each of five 100 ml one-mark volumetric flasks, 0 ml, 5 ml, 10 ml, 15 ml and 20 ml of chromium standard solution (4.3). Add 4 ml of strontium chloride solution (4.1) and 5 ml of hydrochloric acid (Ô20= 1,18 g/ml). Make up to the mark with water and mix. 7.4 Calibration and determination 7.4.1 Atomic absorption measurements Proceed as directed in 7.4.1 of ISO 7530-1, using a wavelength of 357,9 nm and a nitrous oxideacetylene flame. 7.4.2 Preparation of calibration graphs Proceed as directed in 7.4.2 of ISO 7530-1. 7.5 Number of determinations Carry out the determination at least in duplicate. 8 Expression of results 8.1 Calculation Proceed as directed in 8.1 of ISO 7530-1. 8.2 Precision 8.2.1 Laboratory tests Ten laboratories in five countries participated in the testing of this procedure using one sample of nominal composition given in Table 1. 8.2.2 Statistical analysis 8.2.2.1 Results were treated according to ISO 5725 as described in 8.2.2 of ISO 7530-1. The results of this analysis are given in Table 2. 8.2.2.2 One laboratory was rejected as a Cochran outlier and one was rejected as a Dixon outlier. 9 Test report Refer to clause 9 of ISO 7530-1. Table 1 Nominal composition of test samples % (m/m) Table 2 Results of statistical analysis SampleAlCoCrCuFeMnNiSiTi 9020,40,0550,04480,4Remainder0,352,5 Sample reference Mean % (m/m) Within-laboratory standard deviation Between laboratory standard deviation RepeatabilityReproducibility 9025,160,0340,1020,0960,30 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:59:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7455-3:1991 © BSI 11-1999 Publication(s) referred to See national foreword. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:59:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7455-3: 1991 ISO 7530-3: 1990 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI 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. 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