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1、INTERNATIONAL STANDARD IS0 7530-3 First edition 1990-12-15 Nickel alloys - Flame atomic absorption spectrometric analysis - Part 3: Determination of chromium content Alliages de nickel - Analyse par spectrom6trie d/absorption atomique clans la flamme - Partie 3: Dosage du chrome Reference number IS0
2、 7530-3: 1990(E) IS0 7530-3:1990(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body i
3、nterested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the International Electrotec
4、hnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an Inter- national Standard requires approval by at least 75% of the member bodies casting a vo
5、te. International Standard IS0 7530-3 was prepared by Technical Committee ISO/TC 155, Nickel and nickel alloys. IS0 7530 consists of the following parts, under the general title Nickel alloys - Flame atomic absorption spectrometric analysis: - Part I: General requirements and sample dissolution - Pa
6、rt 2: Determination of cobalt content - Part 3: Determination of chromium content - Part 4: Determination of copper content - Part 5: Determination of iron content - Part 6: Determination of manganese content - Part 7: Determination of aluminium content - Part 8: Determination of silicon content - P
7、art 9: Determination of vanadium content 0 IS0 1990 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization
8、 for Standardization Case Postale 56 l CH-1211 Genkve 20 l Switzerland Printed in Switzerland ii -,-,- INTERNATIONAL STANDARD IS0 7530-3:1990(E) Nickel alloys - Flame atomic absorption spectrometric analysis - Part 3: Determination of chromium content 1 Scope This part of IS0 7530 specifies a flame
9、atomic ab- sorption spectrometric method for the determination of chromium in the range of 0,Ol % (m/m) to 4 % (m/m) in nickel alloys. Typical compositions of some nickel alloys are given in IS0 7530-1, annex B. The general requirements concerning the appar- atus, sampling, dissolution of the test s
10、ample, atomic absorption measurements, calculations and test report are given in IS0 7530-I. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of IS0 7530. At the time of publication, the editions indicated wer
11、e valid. All standards are subject to revision, and parties to agreements based on this part of IS0 7530 are encouraged to investi- gate the possibility of applying the most recent edi- tions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International
12、 Standards. IS0 5725:1986, Precision of test methods - Determi- nation of repeatability and reproducibility for a stan- dard test method by inter-laboratory tests. IS0 7530-1:-l), Nickel alloys - Flame atomic ab- sorption spectromefric analysis - Part 1: Genera/ requirements and sample dissolution.
13、1) To be published. 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 ca
14、libration solutions at a wavelength of 357,9 nm. 4 Reagents In addition to the reagents listed in IS0 7530-1, the following special reagents are required. 4.1 Strontium chloride, solution. Transfer 113,5 g of strontium chloride hexahydrate (SrCI,.GH,O) to a 600 ml beaker, dissolve in 400 ml of hot w
15、ater (50 “C to 60 “C), cool and transfer to a 1000 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
16、/m) minimum purity and transfer to a 400 ml beaker. Add 30 ml of hydrochloric acid (pzO = I,18 g/ml) diluted 1 + 1 and heat to com- plete dissolution. Cool, transfer to a 1000 ml one- mark volumetric flask and add 35 ml of hydrochloric acid (pzO = I,18 g/ml). Make up to the mark with water, mix and
17、store in a polyethylene bottle. -,-,- IS0 7530-3:1990(E) 4.3 Chromium, standard solution (50 mg/l). Pipette 50 ml of the chromium standard reference solution (4.2) into a 1000 ml one-mark volumetric flask and add 50 ml of hydrochloric acid (p2u = I,18 g/ml). Make up to the mark with water, mix and s
18、tore in a polyethylene bottle. 5 Apparatus The apparatus required is specified in clause 5 of IS0 7530-I. 6 Sampling and sample preparation Refer to clause 6 of IS0 7530-I 7 Procedure 7.1 Preparation of test solution Proceed as directed in 7.1.1 to 7.1.4 of IS0 7530-I. 7.1.1 Primary dilutions 7.1.1.
19、1 Initial dilution for 0,Ol % (m/m) to 0,lO % (?z/m) chromium Transfer the test solution (7.1) to a 100 ml one-mark volumetric flask. Add 4 ml of strontium chloride sol- ution (4.1). Make up to the mark with water and mix. Remove any products of hydrolysis by settlement and dry filtration or by cent
20、rifuging. 7.1.1.2 Initial dilution for 0,l % (/HZ) 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 (p2u = I,18 g/ml). Make up to the mark with water and mix. Remove any products of hydrolysis by settlement and dry filtrat
21、ion or by centrifuging. 7.1.2 Secondary dilutions 7.1.2.1 Secondary dilution for 0,l % (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 (p20 = I,18 g/ml). Make
22、 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 (ppo = I,18 g/ml). Make up to the mark
23、with water and mix. 7.2 Reagent blank solution Carry out a blank test in parallel with the determi- nation, 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,
24、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 (p20 = I,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
25、 7.4.1 of IS0 7530-1, using a wavelength of 357,9 nm and a nitrous oxide- acetylene flame. 7.4.2 Preparation of calibration graphs Proceed as directed in 7.4.2 of IS0 7530-I. 7.5 Number of determinations Carry out the determination at least in duplicate. 8 Expression of results 8.1 Calculation Proce
26、ed as directed in 8.1 of IS0 7530-I. 8.2 Precision 8.2.1 Laboratory tests Ten laboratories in five countries participated in the testing of this procedure using one sample of nom- inal composition given in table 1. 8.2.2 Statistical analysis 8.2.2.1 Results were treated according to IS0 5725 as desc
27、ribed in 8.2.2 of IS0 7530-I. 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. 2 -,-,- IS0 7530-3:1990(E) 9 Test report Refer to clause 9 of IS0 7530-I. Sample 902 Table 1 - Nominal composition of tes
28、t samples % (m/m) Al co Cr cu Fe Mn Ni Si Ti 0,4 0,05 5 0,04 48 0,4 Remainder 0,35 2,5 Table 2 - Results of statistical analysis Within-laboratory Between Sample reference Mean % (m/m) standard laboratory Repeatability Reproducibility deviation standard deviation 902 5.16 0,034 0,102 0,096 0,30 , 3 -,-,- IS0 7530-3:1990(E) UDC 669.245:543.422:546.76 Descriptors: nickel alloys, chemical analysis, determination of content, chromium, atomic absorption spectrometric method Price based on 3 pages