1、BSI Standards PublicationBS EN ISO 4938:2016Steel and iron Determination of nickelcontent Gravimetric ortitrimetric methodBS EN ISO 4938:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 4938:2016.It supersedes BS 6200-3.20.1:1989 which is withdrawn.The U
2、K participation in its preparation was entrusted to TechnicalCommittee ISE/102, Methods of Chemical Analysis for Iron and Steel.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of
3、 a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 81555 3ICS 77.080.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under th
4、e authority of theStandards Policy and Strategy Committee on 31 March 2016.Amendments/corrigenda issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORMEN ISO 4938 March 2016 ICS 77.080.01 Supersedes EN 24938:1990English Version Steel and iron - Determination of n
5、ickel content - Gravimetric or titrimetric method (ISO 4938:2016) Aciers et fontes - Dtermination du nickel - Mthode gravimtrique ou titrimtrique (ISO 4938:2016) Stahl und Eisen - Bestimmung des Nickelanteils - Gravimetrisches oder titrimetrisches Verfahren (ISO 4938:2016) This European Standard was
6、 approved by CEN on 21 November 2015. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such n
7、ational standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own la
8、nguage and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Gree
9、ce, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG C
10、EN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 4938:2016 EBS EN ISO 4938:2016EN ISO 4938:2016 (E) 3 European foreword This document (EN ISO 4938:2016) has be
11、en prepared by Technical Committee ISO/TC 17 “Steel” in collaboration with Technical Committee ECISS/TC 102 “Methods of chemical analysis for iron and steel” the secretariat of which is held by SIS. This European Standard shall be given the status of a national standard, either by publication of an
12、identical text or by endorsement, at the latest by September 2016, and conflicting national standards shall be withdrawn at the latest by September 2016. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not
13、 be held responsible for identifying any or all such patent rights. This document supersedes EN 24938:1990. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the CEN-CENELEC Internal Regulations, the national
14、 standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuan
15、ia, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 4938:2016 has been approved by CEN as EN ISO 4938:2016 without any modification. BS EN ISO 4938:2016ISO 4938:2016(E
16、)Foreword iv1 Scope . 12 Normative references 13 Principle 14 Reagents 15 Apparatus . 46 Sampling 57 Procedure. 57.1 Test portion 57.2 Determination . 57.2.1 Preparation of the test solution 57.2.2 First nickel precipitation . 57.2.3 Second nickel precipitation 67.2.4 Gravimetric determination . 77.
17、2.5 Titrimetric determination . 78 Expression of results 88.1 Methods of calculation . 88.1.1 Gravimetric determination . 88.1.2 Titrimetric determination . 88.2 Precision . 89 Test report . 9Annex A (informative) Additional information on the international interlaboratory test.10Annex B (informativ
18、e) Graphical representation of precision data .11Annex C (normative) Determination of nickel in combined filtrates by atomic absorption spectrometry 13Bibliography .16 ISO 2016 All rights reserved iiiContents PageBS EN ISO 4938:2016ISO 4938:2016(E)ForewordISO (the International Organization for Stan
19、dardization) 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 committee has been established has the right
20、 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 electrotechnical standardization.The procedures u
21、sed to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules
22、 of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the 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. Details of any patent rights identifi
23、ed during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on t
24、he meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.The committee responsible for this document is ISO
25、/TC 17, Steel, Subcommittee SC 1, Methods of determination of chemical composition.This second edition cancels and replaces the first edition (ISO 4938:1988), which has been technically revised.iv ISO 2016 All rights reservedBS EN ISO 4938:2016INTERNATIONAL STANDARD ISO 4938:2016(E)Steel and iron De
26、termination of nickel content Gravimetric or titrimetric method1 ScopeThis International Standard specifies a method for the determination of nickel in steel and iron by gravimetry or titrimetry.The method is applicable to nickel contents from 1 % to 30 % (mass fraction).2 Normative referencesThe fo
27、llowing documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 648, Labor
28、atory glassware Single-volume pipettesISO 1042, Laboratory glassware One-mark volumetric flasksISO 3696, Water for analytical laboratory use Specification and test methodsISO 4793, Laboratory sintered (fritted) filters Porosity grading, classification and designationISO 14284, Steel and iron Samplin
29、g and preparation of samples for the determination of chemical composition3 PrincipleDissolution of a test portion with appropriate acids.Precipitation of the nickel as nickel-dimethylglyoxime. Cobalt, if present, is oxidized by potassium hexacyanoferrate(lll). Copper, if present with cobalt, prefer
30、ably is removed by controlled potential electrolysis. Acid dissolution of the precipitate and filtration of the solution, followed by a second precipitation of the nickel as nickel dimethylglyoxime.In the case of the gravimetric determination, weighing the dried dimethylglyoxime precipitate.In the c
31、ase of the titrimetric determination, acid dissolution of the precipitate, addition of excess EDTA.Na2solution and back titration of the excess EDTA.Na2by zinc solution using xylenol orange as an indicator.In both cases, determination of residual nickel in the filtrate(s) by atomic absorption spectr
32、ometry (see Annex C).4 ReagentsDuring the analysis, unless otherwise specified, use only reagents of recognized analytical grade and only distilled grade 2 water as specified in ISO 3696 or water of equivalent purity.4.1 Sodium hydrogen sulphate (NaHSO4). ISO 2016 All rights reserved 1BS EN ISO 4938
33、:2016ISO 4938:2016(E)4.2 Ethanol, 95 % (volume fraction).4.3 Acetic acid, glacial, approximately 1,05 g/ml.4.4 Hydrofluoric acid, approximately 1,15 g/ml.WARNING Hydrofluoric acid is extremely irritating and corrosive to skin and mucous membranes producing severe skin burns which are slow to heal. I
34、n case of contact with skin, wash well with water, apply a topical gel containing 2,5 % (mass fraction) calcium gluconate and seek immediate medical treatment.4.5 Nitric acid, approximately 1,40 g/ml.4.6 Perchloric acid, approximately 1,54 g/ml.WARNING Perchloric acid vapour can cause explosions in
35、the presence of ammonia, nitrous fumes or organic material in general.4.7 Sulphuric acid, approximately 1,84 g/ml.4.8 Ammonia solution, approximately 0,90 g/ml.4.9 Hydrochloric acid, approximately 1,19 g/ml, diluted 1 + 1.Add 500 ml of hydrochloric acid ( approximately 1,19 g/ml) to 500 ml of water.
36、4.10 Hydrochloric acid, approximately 1,19 g/ml, diluted 1 + 99.Add 10 ml of hydrochloric acid ( approximately 1,19 g/ml) to 990 ml of water.4.11 Nitric acid, approximately 1,40 g/ml, diluted 2 + 3.Add 200 ml of nitric acid (4.5) to 300 ml of water.4.12 Perchloric acid, approximately 1,54 g/ml, dilu
37、ted 1 + 49.Add 10 ml of perchloric acid (4.6) to 490 ml of water.4.13 Ammonia solution, approximately 0,90 g/ml, diluted 1 + 1.Add 500 ml of ammonia solution (4.8) to 500 ml of water.4.14 Ammonia solution, approximately 0,90 g/ml, diluted 1 + 3.Add 100 ml of ammonia solution (4.8) to 300 ml of water
38、.4.15 Hydrochloric/nitric acids mixture.Mix three volumes of hydrochloric acid ( approximately 1,19 g/ml) with one volume of nitric acid (4.5).Prepare this mixture immediately prior to use.4.16 Ammonium acetate, 200 g/l solution.2 ISO 2016 All rights reservedBS EN ISO 4938:2016ISO 4938:2016(E)4.17 A
39、mmonium citrate buffer solution.Dissolve 500 g of citric acid monohydrate (C6H8O7H2O) in 675 ml of ammonia solution (4.8) and dilute to 1 l with water.Filter before use.4.18 Citric acid, 500 g/l solution.Dissolve 500 g of citric acid monohydrate (C6H8O7H2O) in water and dilute to 1 l with water.Filt
40、er before use.4.19 Dimethylglyoxime, 30 g/l solution in alkaline medium.Dissolve 20 g of potassium hydroxide in 400 ml of water, add 30 g of dimethylglyoxime (C4H8N2O2) and stir until dissolution is complete. Dilute to 1 l with water and mix.Filter before use.4.20 Dimethylglyoxime, 10 g/l solution i
41、n ethanol.Dissolve 10 g of dimethylglyoxime (C4H8N2O2) in 1 000 ml of ethanol (4.2).Filter before use.4.21 Hydrazine dihydrogen sulphate (N2H6SO4), 100 g/l solution.4.22 Potassium hexacyanoferrate(III), K3Fe(CN)6, 100 g/l solution.This solution is stable for approximately 30 days.1 ml of this soluti
42、on corresponds approximately to 0,02 g of cobalt and manganese, respectively.4.23 Washing water, adjusted to pH 8 with a few drops of ammonia solution (4.13).4.24 Ethylenediaminetetraacetic acid disodium salt (EDTA.Na2), standard-volumetric solution.4.24.1 Preparation of the solutionDissolve 6,33 g
43、of ethylenediaminetetraacetic acid disodium salt (C10H14O8N2Na22H2O) in water, transfer the solution to a 1 000 ml one-mark volumetric flask, dilute to the mark with water and mix.1 ml of this standard solution corresponds approximately to 1 mg of nickel.4.24.2 Standardization of the solutionTransfe
44、r 25,0 ml of the nickel standard solution (4.24.3) to a 250 ml beaker and add 33 ml of EDTA.Na2solution (4.24.1). Add 15 ml of ammonium acetate solution (4.16) and dilute to about 150 ml with water. Continue as described in the third paragraph of 7.2.5. ISO 2016 All rights reserved 3BS EN ISO 4938:2
45、016ISO 4938:2016(E)The corresponding concentration, c, of the EDTA.Na2solution (4.24.1), expressed in milligrams of nickel per millilitre, is given by Formula (1):cmmVV=()+()121225(1)wherem1is the mass of nickel contained in 1 ml of the nickel standard solution (4.24.3), in milligrams;m2is the mass
46、of nickel corresponding to 1 ml of the zinc standard solution (4.25), in milligrams;V1is the volume of the zinc standard solution (4.25) used for the titration, in millilitres;V2is the volume of the EDTA.Na2solution (4.24.1) used for the standardization, in millilitres.4.24.3 Nickel standard solutio
47、nWeigh, to the nearest 0,1 mg, 1,000 g of nickel Ni 99,95 % (mass fraction). Dissolve in 20 ml of nitric acid (4.11). Boil to remove nitrous fumes, cool, transfer quantitatively to a 1 000 ml one-mark volumetric flask, dilute to the mark with water and mix.1 ml of this standard solution contains 1,0
48、 mg of nickel.4.25 Zinc standard solution.Weigh, to the nearest 0,1 mg, 1,114 0 g of zinc purity 99,9 % mass fraction and transfer to a 300 ml beaker. If the zinc is oxidized, it should be cleaned with hydrochloric acid (4.9), water and acetone, and dried for 5 min at 110 C before use.Add about 50 m
49、l of water, 20 ml of hydrochloric acid (4.9) and five drops of bromine-saturated water. Cover with a watch glass and heat until the metal is completely dissolved. Continue the heating until the colour of the bromine disappears, cool to room temperature and add 20 ml of glacial acetic acid (4.3). Adjust the pH of the solution to 6,0 0,2 with ammonia solution (4.14). Transfer quantitatively to a 1 000 ml one-mark volumetric flask, dilute to the mark with water and mix.1 ml of this standard solution c
