oSIST prEN ISO 8407:2020

Corrosion of metals and alloys - Removal of corrosion products from corrosion test specimens (ISO/DIS 8407:2020)

Korrosion von Metallen und Legierungen - Entfernen von Korrosionsprodukten von Korrosionsprobekörpern (ISO/DIS 8407:2020)

Dieses Dokument legt Verfahren für das Entfernen von Korrosionsprodukten fest, die sich während der Auslagerung von Korrosionsprobekörpern aus Metallen und Legierungen in korrosiven Umgebungen gebildet haben. In diesem Dokument bezieht sich der Begriff „Metalle“ auf reine Metalle und Legierungen.
Die aufgeführten Verfahren wurden entwickelt, um alle Korrosionsprodukte zu entfernen, ohne das Grundmetall signifikant zu entfernen. Dadurch ist eine genaue Bestimmung des Masseverlustes des Metalls möglich, der während der Auslagerung in korrosiver Umgebung stattfindet.
Diese Verfahren sind in einigen Fällen auch bei metallischen Beschichtungen anwendbar, vorausgesetzt, dass die möglichen Einwirkungen durch das Substrat berücksichtigt werden.

Corrosion des métaux et alliages - Élimination des produits de corrosion sur les éprouvettes d'essai de corrosion (ISO/DIS 8407:2020)

Korozija kovin in zlitin - Odstranjevanje produktov korozije s preskusnih vzorcev (ISO/DIS 8407:2020)

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN ISO 8407:2020
01-marec-2020

Korozija kovin in zlitin - Odstranjevanje produktov korozije s preskusnih vzorcev

(ISO/DIS 8407:2020)

Corrosion of metals and alloys - Removal of corrosion products from corrosion test

specimens (ISO/DIS 8407:2020)
Korrosion von Metallen und Legierungen - Entfernen von Korrosionsprodukten von
Korrosionsprobekörpern (ISO/DIS 8407:2020)
Corrosion des métaux et alliages - Élimination des produits de corrosion sur les
éprouvettes d'essai de corrosion (ISO/DIS 8407:2020)
Ta slovenski standard je istoveten z: prEN ISO 8407
ICS:
77.060 Korozija kovin Corrosion of metals
oSIST prEN ISO 8407:2020 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 8407:2020
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oSIST prEN ISO 8407:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 8407
ISO/TC 156 Secretariat: SAC
Voting begins on: Voting terminates on:
2020-01-13 2020-04-06
Corrosion of metals and alloys — Removal of corrosion
products from corrosion test specimens

Corrosion des métaux et alliages — Élimination des produits de corrosion sur les éprouvettes d'essai de

corrosion
ICS: 77.060
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 8407:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2020
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oSIST prEN ISO 8407:2020
ISO/DIS 8407:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

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ii © ISO 2020 – All rights reserved
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oSIST prEN ISO 8407:2020
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Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Procedures .................................................................................................................................................................................................................. 1

4.1 General ........................................................................................................................................................................................................... 1

4.2 Chemical procedures ......................................................................................................................................................................... 3

4.3 Electrolytic procedures .................................................................................................................................................................... 4

4.4 Mechanical procedures .................................................................................................................................................................... 4

5 Test report ................................................................................................................................................................................................................... 4

Annex A (informative) Chemical and electrolytic cleaning procedures for removal of

corrosion products ............................................................................................................................................................................................. 5

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Foreword

ISO (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 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 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 approval 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 the 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 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 voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/ iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 156, Corrosion of metals and alloys., WG 6,

General principles of testing and data interpretation.

This third edition cancels and replaces the second edition (ISO 8407:2009), which has been technically

revised.
The main changes compared to the previous edition are as follows:
— Annex A
A list of all parts in the ISO 8407:2009 series can be found on the ISO website.
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oSIST prEN ISO 8407:2020
DRAFT INTERNATIONAL STANDARD ISO/DIS 8407:2020(E)
Corrosion of metals and alloys — Removal of corrosion
products from corrosion test specimens

WARNING — Safety rules for personnel: handling of the solutions used for removal of corrosion

products must be left to skilled personnel or conducted under their control. The equipment must

be used and maintained by skilled personnel, not only so that the procedures can be performed

correctly, but also because of the hazards to health and safety that are involved.

1 Scope

This document specifies procedures for the removal of corrosion products formed on metal and alloy

corrosion test specimens during their exposure in corrosive environments. For the purpose of this

document, the term "metals" refers to pure metals and alloys.

The specified procedures are designed to remove all corrosion products without significant removal of

base metal. This allows an accurate determination of the mass loss of the metal, which occurred during

exposure to the corrosive environment.

These procedures may, in some cases, also be applied to metal coatings. However, possible effects from

the substrate must be considered.

NOTE If a significant portion of the substrate is visible after the pickling procedure is completed, the results

will be unreliable.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at http:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Procedures
4.1 General

4.1.1 A light mechanical cleaning treatment by brushing with a soft bristle brush under running water

should first be applied to remove lightly adherent or bulky corrosion products.

4.1.2 If the treatment described in 4.1.1 does not remove all corrosion products, it will be necessary to

use other procedures. These are of three types:
a) chemical;
b) electrolytic;
c) more vigorous mechanical treatments.
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oSIST prEN ISO 8407:2020
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NOTE These treatments will also remove some base metal.

Whichever method is used, it might be necessary to repeat the cleaning treatment to ensure complete

removal of the corrosion products. Removal shall be confirmed by visual examination. The use of a low-

power microscope (i.e. x7 to x30) is particularly helpful with a pitted surface since corrosion products

may accumulate in pits.

4.1.3 An ideal procedure should remove corrosion products and not result in removal of any base

metal. Two procedures can be used to confirm this point. One procedure uses a control specimen

(4.1.3.1) and the other requires a certain number of cleaning cycles on the corroded specimen (4.1.3.2).

The procedures shall be maintained during the entire service life of the cleaning solutions listed in Tables

A.1 and A.2.

NOTE 1 Indications that the solution needs to be discarded can be discoloration or significant amount of

corrosion products in the solution.

NOTE 2 Some solutions might need some “running in” before working without etching the substrate.

4.1.3.1 Uncorroded control specimens, which should be similar chemically, metallurgically, and

geometrically to the test specimens, should be cleaned by the same procedure as used for the test

specimen. By weighing the control specimen before and after cleaning (weighing to the fifth significant

figure is suggested, e.g. a 70 g specimen should be weighed to three decimal places), the metal loss

resulting from cleaning may be determined. The mass loss of the control specimen will reflect the mass

loss of test specimens resulting from the cleaning procedure.

4.1.3.2 The cleaning of each corroded test specimen should be repeated several times after the removal

of the corrosion products is completed. The mass shall be plotted as a function of the number of equal

cleaning cycles (see Figure 1). Point A represents the mass of corroded specimens before the start of the

cleaning. In many cases two straight lines, AB and BC, will be obtained. Line AB characterizes the removal

of corrosion products and may not always be visible. Line BC characterizes the removal of substrate after

the corrosion products are gone. Point D, which characterizes the mass of the pure metal at zero number

of cleaning cycles, is obtained by extrapolation of line BC to the ordinate axis. In some cases, the relation

may not be linear and the most appropriate extrapolation shall then be made.

If no intervals of equal cleaning cycles are used during one cleaning procedure, the x-axis should be

expressed in time units.
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Key
X numbers of cleaning cycles or time units
Y mass
Figure 1 — Mass of corroded specimens after repetitive cleaning cycles

NOTE The number of points needed to establish the line BC can be less than indicated in the figure for the

specific case, especially if there is significant experience for the pickled material and solution.

4.1.3.3 The true mass of the specimen, after removal of the corrosion products, will be a value between

the masses represented by the points B and D, depending on the degree of protection furnished by the

corrosion products during the cleaning procedure. If the relation from B to C is not linear, the point D

should be obtained by a mathematical formula such as a least square method from reliable last points of

cleaning cycles
4.1.4 The preferred cleaning method will be that which
a) provides efficient removal of corrosion products,

b) provides low or zero mass loss when applied to new uncorroded specimens (see 4.1.3.1), and

c) provides a curve of mass as a function of the number of cleaning cycles or time of pickling, which is

close to horizontal when the latter is plotted as the abscissa (see 4.1.3.2).

4.1.5 When chemical or electrolytic procedures are used, solutions freshly prepared with distilled or

deionized water and reagent grade chemicals shall be used.

4.1.6 After cleaning, the specimen should be thoroughly rinsed with tap water, a light brushing during

this procedure will help to remove any remaining surface products resulting from the cleaning process.

Finally, the specimens shall be rinsed with distilled or deionized water. The specimen shall then be rinsed

thoroughly in ethanol and dried using a hot air blower or an oven. After that, the specimens shall be

allowed to cool in a dessicator to the balance room temperature before weighing.
4.2 Chemical procedures

4.2.1 Chemical procedures involve immersion of the corrosion test specimen in a chemical solution

which is specifically designed to remove the corrosion products with minimal dissolution of any base

metal. Several procedures are listed in Annex A (see Table A.1). To facilitate the cleaning, it is strongly

recommended to use an ultrasonic bath treatment.
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4.2.2 Chemical cleaning is often preceded by light brushing of the test specimen to remove lightly

adherent, bulky corrosion products.

4.2.3 Before the chemical treatment, clean the specimens as described in 4.1.1. In connection with

the intermittent removal of specimens for weighing, brush the specimens, if necessary, to facilitate the

removal of tightly adherent corrosion products.
4.3 Electrolytic procedures

Electrolytic cleaning can also be used to remove corrosion products. Several methods of electrolytic

cleaning of corrosion test specimens are given in Annex A (see Table A.2). To facilitate the cleaning, it is

strongly recommended to use an ultrasonic bath treatment.

Electrolytic cleaning should be preceded by light brushing of the test specimen to remove lightly

adherent, bulky corrosion products. Brushing should also follow electrolytic cleaning to remove any

loose slime or deposits. This will help to minimize
...