1、August 2016 English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 77.040.30!%Y.Q“2541146www.din.deD
2、IN EN ISO 4938Steel and iron Determination of nickel content Gravimetric or titrimetric method (ISO 4938:2016);English version EN ISO 4938:2016,English translation of DIN EN ISO 4938:2016-08Stahl und Eisen Bestimmung des Nickelanteils Gravimetrisches oder titrimetrisches Verfahren (ISO 4938:2016);En
3、glische Fassung EN ISO 4938:2016,Englische bersetzung von DIN EN ISO 4938:2016-08Aciers et fontes Dtermination du nickel Mthode gravimtrique ou titrimtrique (ISO 4938:2016);Version anglaise EN ISO 4938:2016,Traduction anglaise de DIN EN ISO 4938:2016-08SupersedesDIN EN 24938:1992-10www.beuth.deDocum
4、ent comprises 22 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.08.16 DIN EN ISO 4938:2016-08 2 A comma is used as the decimal marker. National foreword This document (EN ISO 4938:2016) has been prepared by Technical Committee
5、 ISO/TC 17 “Steel” in collaboration with Technical Committee ECISS/TC 102 “Methods of chemical analysis for iron and steel” (Secretariat: SIS, Sweden). The responsible German body involved in its preparation was DIN-Normenausschuss Eisen und Stahl (DIN Standards Committee Iron and Steel), Working Co
6、mmittee NA 021-00-30 AA Analysenverfahren. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 648 DIN EN ISO 648 ISO 1042 DIN EN ISO 1042 ISO 3696 DIN ISO 3696 ISO 5725*)DIN ISO 5725*)ISO 14284 DIN EN ISO 14284 Amendments This standard dif
7、fers from DIN EN 24938:1992-10 as follows: a) the last paragraph in Clause 3 has been newly added; b) the standard has been issued in collaboration with CEN as an ISO Standard in the parallel voting procedure; c) the standard has been editorially revised. Previous editions DIN EN 24938: 1992-10 Nati
8、onal Annex NA (informative) Bibliography DIN EN ISO 648, Laboratory glassware Single-volume pipettes DIN EN ISO 1042, Laboratory glassware One-mark volumetric flasks DIN ISO 3696, Water for analytical laboratory use Specification and test methods DIN ISO 5725, Precision of test methods Determination
9、 of repeatability and reproducibility for a standard test method by interlaboratory tests*)DIN EN ISO 14284, Steel and iron Sampling and preparation of samples for the determination of chemical composition *)Has been replaced by the ISO 5725 standards series. *)Has been replaced by the DIN ISO 5725
10、standards series. EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 4938 March 2016 ICS 77.080.01 Supersedes EN 24938:1990English Version Steel and iron - Determination of nickel content - Gravimetric or titrimetric method (ISO 4938:2016) Aciers et fontes - Dtermination du nickel - Mthode gra
11、vimtrique ou titrimtrique (ISO 4938:2016) Stahl und Eisen - Bestimmung des Nickelanteils - Gravimetrisches oder titrimetrisches Verfahren(ISO4938:2016) This European Standard was approved by CEN on 21 November 2015. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stip
12、ulate 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 national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European
13、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 language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the
14、 national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania
15、, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any
16、 means reserved worldwide for CEN national Members. Ref. No. EN ISO 4938:2016 EForeword . 41 Scope . 52 Normative references 53 Principle 54 Reagents 55 Apparatus . 86 Sampling 97 Procedure. 97.1 Test portion 97.2 Determination . 97.2.1 Preparation of the test solution 97.2.2 First nickel precipitat
17、ion . 97.2.3 Second nickel precipitation . 107.2.4 Gravimetric determination 117.2.5 Titrimetric determination 118 Expression of results .128.1 Methods of calculation 128.1.1 Gravimetric determination 128.1.2 Titrimetric determination 128.2 Precision 129 Test report 13Annex A (informative) Additiona
18、l information on the international interlaboratory test.14Annex B (informative) Graphical representation of precision data .15Annex C (normative) Determination of nickel in combined filtrates by atomic absorption spectrometry 17Bibliography .20Contents PageEN ISO 4938:2016 (E) DIN EN ISO 4938:2016-0
19、8 2European foreword . 3European foreword This document (EN ISO 4938:2016) has been 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 Standa
20、rd shall be given the status of a national standard, either by publication of an 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 o
21、f this document may be the subject of patent rights. CEN and/or CENELEC shall not 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 T
22、rade Association. According to the CEN-CENELEC Internal Regulations, the national 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 Mace
23、donia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, 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
24、 as EN ISO 4938:2016 without any modification. EN ISO 4938:2016 (E) DIN EN ISO 4938:2016-08 3 ForewordISO (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
25、 out through ISO technical committees. Each member body interested in a subject for which a technical 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
26、 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different a
27、pproval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules 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 th
28、e subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified 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
29、 trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in th
30、e Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.The committee responsible for this document is ISO/TC 17, Steel, Subcommittee SC 1, Methods of determination of chemical composition.This second edition cancels and replaces the first edition (ISO 4938:19
31、88), which has been technically revised.EN ISO 4938:2016 (E) DIN EN ISO 4938:2016-08 4 1 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 No
32、rmative referencesThe following 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
33、) applies.ISO 648, Laboratory 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
34、, Steel and iron Sampling 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 pre
35、sent with cobalt, preferably 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 dimethylglyox
36、ime precipitate.In the case 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
37、atomic absorption spectrometry (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).EN ISO 4938:2016 (E)
38、DIN EN ISO 4938:2016-08 5 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 he
39、al. In 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 explosion
40、s in 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 w
41、ater.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,
42、 diluted 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
43、water.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.EN ISO 4938:2016 (E) DIN EN ISO 4938:2016-08 6 The corresponding c
44、oncentration, 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 of nickel corresponding to 1 ml of the
45、 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 solutionWeigh, to the nearest 0,1 mg, 1,000 g
46、 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 mg of nickel.4.25 Zinc standard solut
47、ion.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 ml of water, 20 ml of hydrochloric acid
48、 (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 ma
