EN 24937:1990
(Main)Steel and iron - Determination of chromium content - Potentiometric or visual method (ISO 4937:1986)
Steel and iron - Determination of chromium content - Potentiometric or visual method (ISO 4937:1986)
The method is applicable to chromium contents between 0.25 % (m/m) and 35 % (m/m). Specifies principle, reagents, apparatus, sampling, procedure, expression of results and test report. Annex A gives additional information on the international co-operative tests, and Annex B represents the precision data graphically.
Stahl und Eisen - Bestimmung des Chromgehalts - Potentiometrische oder visuelle Methode (ISO 4937:1986)
Qualitaet. Rationalisierung.
Aciers et fontes - Détermination de la teneur en chrome - Méthode potentiométrique ou visuelle (ISO 4937:1986)
La présente Norme internationale spécifie une méthode de dosage par titrage potentiométrique ou visuel du chrome dans les aciers et les fontes. La méthode est applicable aux teneurs en chrome comprises entre 0,25 et 35 % (m/m). En présence de vanadium, le titrage visuel ne s'applique qu'aux prises d'essai contenant moins de 3 mg de vanadium.
Jeklo in železo - Določevanje kroma - Potenciometrična ali vizualna metoda (ISO 4937:1996)
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Stahl und Eisen - Bestimmung des Chromgehalts - Potentiometrische oder visuelle Methode (ISO 4937:1986)Aciers et fontes - Détermination de la teneur en chrome - Méthode potentiométrique ou visuelle (ISO 4937:1986)Steel and iron - Determination of chromium content - Potentiometric or visual method (ISO 4937:1986)77.080.01Železne kovine na splošnoFerrous metals in generalICS:Ta slovenski standard je istoveten z:EN 24937:1990SIST EN 24937:1997en01-december-1997SIST EN 24937:1997SLOVENSKI
STANDARD
SIST EN 24937:1997
SIST EN 24937:1997
SIST EN 24937:1997
G - International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.ME~YHAPO~HAfl OPrAHM3Al&lR fl0 CTAH~APTM3ALWWORGANISATION INTERNATIONALE DE NORMALISATION Steel and iron - Determination of chromium content - Potentiometric or visual titration method Aciers et fontes - Dosage du chrome - M&hode par titrage potentiome trique ou visuel First edition - 1986-12-15 UDC 629.13/.14 : 543.24/.25 : 546.76 Ref. No. ISO 4937-1986 (E) Descriptors : steels, iron, Chemical analysis, determination of content, chromium, potentiometric methods, volumetric analysis. F; % 0 v) Price based on 8 pages SIST EN 24937:1997
Foreword ISQ (the International Organization for Standardization) is a worldwide federation of national Standards bodies (ISO member bedies). The work of preparing International Standards is normally carried out through ISO technical committees. Esch 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, govern- mental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISQ Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 4937 was prepared by Technical Committee ISO/TC 17, S teel. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless othervvise stated. 0 International Organization for Standardkation, 1986 Printed in Switzerland SIST EN 24937:1997
INTERNATIONAL STANDARD ISO 49374986 IE) Steel and iron - Determination of chromium content - Potentiometric or visual titration method 1 Scope and field of application This International Standard specifies a method for the deter- mination of chromium in steel and iron by potentiometric or visual titration. The method is applicable to chromium contents between 0,25 and 35 % (mlm). If vanadium is present, the visual titration is applicable only to test portions containing less than 3 mg of vanadium. 2 References ISO 377, Wrought steel - Selection and preparation of samples and test pieces. ISO 385/1, Laboratory gfassware - Burettes - Part I: General requiremen ts. ISO 648, Laboratory glassware - One-mark pipettes. I S 0 1042, L abora tot-y glassware - One-mark volume tric flasks. ISO 5725, Precision of test methods - Determination of repea tability and reproducibifity b y in ter-labora tory tes ts. 3 Principle Dissolution of a test Portion with appropriate acids. Oxidation of chromium in an acid medium to chromium(Vl) by ammonium peroxydisulfate in the presence of silver sulfate. Reduction of manganese(VII) by hydrochloric acid. Reduction of chromium(VIf by ammonium iron(ll) sulfate stan- dard solution. In the case of potentiometric detection, determination of the equivalence Point by measurement of the potential Variation when the ammonium iron(ll) sulfate Standard Solution is being added. In the case of visual detection, titration of the excess am- monium iron(ll) sulfate by potassium permanganate Standard Solution which also acts as the indicator. 4 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity, free from oxidizing or reducing activity. 4.1 Urea. 4.2 Perchlorit acid, Q approximately 1,67 g/ml. 4.3 Hydrofluoric acid, Q approximately l,l5 g/mI. 4.4 Orthophosphoric acid, Q approximately 1,70 g/ml. 4.5 Nitrit acid, Q approximately 140 g/ml. 4.6 Hydrochlorit acid, Q approximately 1,19 g/ml, diluted 1 + 1. 4.7 Hydrochlorit acid, Q approximately 1,19 g/ml, diluted 1 + 10. 4.8 Sulfuric acid, Q approximately 1,84 g/ml, diluted 1 + 1. 4.9 Sulfuric acid, Q approximately IJ34 g/ml, diluted 1 + 5. 4.10 Sulfuric acid, ,Q approximately 1,84 g/ml, diluted 1 + 19. 4.11 Silver sulfate, 5 g/l Solution. 4.12 Ammonium peroxydisulfate [(NH&S208], 500 g/l Solution. Prepare this solution immediately before use. 4.13 Manganese sulfate [MnS0,*H201, 4 g/i Solution. 4.14 Mang
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.