CEN/TS 14940-1:2009

Copper and copper alloys - Determination of chromium content - Part 1: Titrimetric method

This part of this document specifies a titrimetric method for the determination of the chromium content of
copper and copper alloys in the form of castings or unwrought or wrought products.
The method is applicable to products having chromium mass fractions between 0,10 % and 2,0 %.

Kupfer und Kupferlegierungen - Bestimmung des Chromgehaltes - Teil 1: Titrimetrisches Verfahren

Dieser Teil dieses Dokuments legt ein titrimetrisches Verfahren für die Bestimmung des Chromgehaltes in
Kupfer und Kupferlegierungen fest, die als Gussstücke oder als plastisch oder nicht plastisch geformte Produkte
vorliegen.
Das Verfahren ist geeignet für Produkte mit Chrom-Massenanteilen zwischen 0,10 % und 2,0 %.

Cuivre et alliages de cuivre - Dosage du chrome - Partie 1: Méthode titrimétrique

La présente partie de ce document spécifie une méthode titrimétrique permettant de doser le chrome dans le
cuivre et les alliages de cuivre sous la forme de produits non corroyés, corroyés ou moulés.
La méthode s’applique aux produits présentant une teneur en chrome comprise entre 0,10 % et 2,0 % en
masse.

Baker in bakrove zlitine - Določevanje kroma - 1. del: Titrimetrijske metode

Ta del tega dokumenta opredeljuje titrimetrijsko metodo določevanja kroma v bakru in bakrovih zlitinah v obliki odlitkov ali neobdelanih oziroma obdelanih proizvodov. Metoda se uporablja za proizvode, ki imajo masne deleže kroma med 0.10 in 2.0 %.

General Information

• Status: Published
• Publication Date: 20-Oct-2009
• ICS: 77.040.30 - Chemical analysis of metals
• ICS: 77.120.30 - Copper and copper alloys
• Technical Committee: CEN/TC 133 - Copper and copper alloys
• Drafting Committee: CEN/TC 133/WG 10 - Methods of analysis
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 07-Nov-2012
• Completion Date: 07-Nov-2012
• Ref Project: SIST-TS CEN/TS 14940-1:2010 - Copper and copper alloys - Determination of chromium content - Part 1: Titrimetric method

Overview

CEN/TS 14940-1:2009 - Copper and copper alloys - Determination of chromium content - Part 1: Titrimetric method - is a European technical specification that defines a titrimetric (potentiometric) procedure to measure chromium mass fraction in copper and copper alloys. It applies to cast, unwrought and wrought products with chromium contents between 0.10 % and 2.0 %. The document describes sampling references, reagents, apparatus, a step-by-step analytical procedure and rules for expressing results.

Key topics and requirements

• Scope and applicability: Chromium determination in copper and copper alloys (0.10–2.0 % Cr).
• Sampling: Follow ISO 1811-1 or ISO 1811-2; test samples prepared as fine drillings, chips or millings (max 0.5 mm thickness).
• Principle: Dissolve test portion → oxidize chromium(III) to chromium(VI) (perchloric + orthophosphoric acid; KMnO4) → reduce chromium(VI) with iron(II) ammonium sulphate → determine endpoint potentiometrically while titrating with the iron(II) solution.
• Reagents: Analytical-grade acids (HCl, HNO3, HF, HClO4, H2SO4, H3PO4), potassium permanganate, potassium dichromate standard solution, iron(II) ammonium sulphate titrant. The iron(II) titrant must be standardized daily against the K2Cr2O7 standard.
• Apparatus: Potentiometric titration setup (electrodes, stirrer), beakers (e.g., 600 ml tall-form).
• Procedure highlights: Typical test portion is 2.00 g; controlled dissolution with acid mix, oxidation steps, blank test, check test with reference material, and potentiometric titration to a clear potential shift (document notes ~200 mV change, between ~900 mV and 700 mV using a platinum/saturated calomel electrode).
• Expression of results: Chromium mass fraction (%) calculated from measured titrant volumes (sample and blank), titrant titre (mg Cr per ml) and sample mass.
• Safety: Strong cautions for use of hydrofluoric acid and perchloric acid - special fume hoods and handling procedures required.

Applications and users

• Quality control and composition verification in metallurgical and materials testing laboratories.
• Producers and processors of copper alloys (castings, wrought products) for specification compliance and product certification.
• Third‑party testing bodies, research labs, and standards organizations validating chromium content for alloy design, failure analysis, and regulatory reporting.
• Use case examples: batch acceptance testing, alloy certification, cross-check of instrumental methods (e.g., FAAS/ICP).

Related standards

• EN 14940-2: Chromium determination by FAAS (complementary instrumental method).
• ISO 1811-1 / ISO 1811-2: Sampling and preparation for chemical analysis of copper alloys.
• ISO 6437 and national methods (e.g., BS 6721-10) referenced historically for titrimetric chromium analysis.

Keywords: CEN/TS 14940-1:2009, copper and copper alloys, chromium determination, titrimetric method, potentiometric titration, iron(II) ammonium sulphate, potassium dichromate, sample preparation, alloy quality control.

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2010
%DNHULQEDNURYH]OLWLQH'RORþHYDQMHNURPDGHO7LWULPHWULMVNHPHWRGH
Copper and copper alloys - Determination of chromium content - Part 1: Titrimetric
method
Kupfer und Kupferlegierungen - Bestimmung des Chromgehaltes - Teil 1: Titrimetrisches
Verfahren
Cuivre et alliages de cuivre - Dosage du chrome - Partie 1: Méthode titrimétrique
Ta slovenski standard je istoveten z: CEN/TS 14940-1:2009
ICS:
77.120.30 Baker in bakrove zlitine Copper and copper alloys
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN/TS 14940-1
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
October 2009
ICS 77.040.30; 77.120.30
English Version
Copper and copper alloys - Determination of chromium content -
Part 1: Titrimetric method
Cuivre et alliages de cuivre - Dosage du chrome - Partie 1: Kupfer und Kupferlegierungen - Bestimmung des
Méthode titrimétrique Chromgehaltes - Teil 1: Titrimetrisches Verfahren
This Technical Specification (CEN/TS) was approved by CEN on 23 May 2009 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 14940-1:2009: E
worldwide for CEN national Members.

Contents Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Principle .4
4 Reagents and materials .4
5 Apparatus .6
6 Sampling .6
7 Procedure .6
8 Expression of results .7
9 Test report .7
Bibliography .8

Foreword
This document (CEN/TS 14940-1:2009) has been prepared by Technical Committee CEN/TC 133 “Copper
and copper alloys”, the secretariat of which is held by DIN.
Within its programme of work, Technical Committee CEN/TC 133 requested CEN/TC 133/WG 10 "Methods of
Analysis" to prepare the following document:
CEN/TS 14940-1, Copper and copper alloys — Determination of chromium content — Part 1: Titrimetric
method
This is one of two parts of the document for the determination of chromium content in copper and copper al-
loys. The other part is:
EN 14940-2, Copper and copper alloys — Determination of chromium content — Part 2: FAAS method.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech Re-
public, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithua-
nia, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Swe-
den, Switzerland and the United Kingdom.

1 Scope
This part of this document specifies a titrimetric method for the determination of the chromium content of
copper and copper alloys in the form of castings or unwrought or wrought products.
The method is applicable to products having chromium mass fractions between 0,10 % and 2,0 %.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated refer-
ences, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 1811-1, Copper and copper alloys — Selection and preparation of samples for chemical analysis —
Part 1: Sampling of cast unwrought products
ISO 1811-2, Copper and copper alloys — Selection and preparation of samples for chemical analysis —
Part 2: Sampling of wrought products and castings
NOTE Informative references to documents used in the preparation of this standard, and cited at the appropriate
places in the text, are listed in the Bibliography.
3 Principle
Dissolution of a test portion followed by oxidation of the greater part of chromium by perchloric acid in the
presence of orthophosphoric acid to avoid loss of chromium. Oxidation of residual chromium(III) by potassium
perman
...