EN ISO 3651-1:1998

SLOVENSKI STANDARD
01-februar-2000
Ugotavljanje odpornosti nerjavnih jekel proti medkristalni koroziji - 1. del:
Avstenitna in feritno-avstenitna (dupleksna) nerjavna jekla - Korozijski preskus v
mediju, ki vsebuje dušikovo kislino, z merjenjem izgube mase (Hueyev preskus)
(ISO 3651-1:1998)
Determination of resistance to intergranular corrosion of stainless steels - Part 1:
Austenitic and ferritic-austenitic (duplex) stainless steels - Corrosion test in nitric acid
medium by measurement of loss in mass (Huey test) (ISO 3651-1:1998)
Ermittlung der Beständigkeit nichtrostender Stähle gegen interkristalline Korrosion - Teil
1: Nichtrostende austenitische und ferritisch-austenitische (Duplex-) Stähle
Korrosionsversuch in Salpetersäure durch Messung des Massenverlustes (Huey-Test)
(ISO 3651-1:1998)
Détermination de la résistance a la corrosion intergranulaire des aciers inoxydables -
Partie 1: Aciers austénitiques et austéno-ferritiques (duplex) - Essai de corrosion en milie
u acide nitrique par mesurage de la perte de masse (essai de Huey) (ISO 3651-1:1998)
Ta slovenski standard je istoveten z: EN ISO 3651-1:1998
ICS:
77.060 Korozija kovin Corrosion of metals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 3651-1
Second edition
1998-05-15
Determination of resistance to intergranular
corrosion of stainless steels —
Part 1:
Austenitic and ferritic-austenitic (duplex)
stainless steels — Corrosion test in nitric acid
medium by measurement of loss in mass
(Huey test)
Détermination de la résistance à la corrosion intergranulaire des aciers
inoxydables —
Partie 1: Aciers inoxydables austénitiques et austéno-ferritiques (duplex) —
Essai de corrosion en milieu acide nitrique par mesurage de la perte de
masse (essai de Huey)
A
Reference number
ISO 3651-1:1998(E)
ISO 3651-1:1998(E)
Contents Page
1 Scope . 1
2 Purpose of the test . 1
2.1 Verification of the intrinsic resistance of
the alloy to intergranular corrosion . 1
2.2 Inspection of the efficiency of the solution
treatment . 1
Heat treatment of sensitization .
3 2
4 Corrosion test . 2
4.1 Principle . 2
4.2 Test pieces . 2
5 Apparatus . 3
6 Corrosive solution . 5
7 Procedure . 5
8 Calculation . 5
9 Test report . 6
©  ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
ii
©
ISO ISO 3651-1:1998(E)
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.
Draft International Standards adopted by the technical committees
are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the
member bodies casting a vote.
International Standard ISO 3651-1 was prepared by Technical
Committee ISO/TC 17, Steel, Subcommittee SC 7, Methods of
testing (other than mechanical tests and chemical analysis)
.
This second edition cancels and replaces the first edition
(ISO 3651-1:1976), which has been technically revised.
ISO 3651 consists of the following parts, under the general title
Determination of resistance to intergranular corrosion of stainless
steels:
— Part 1: Austenitic and ferritic-austenitic (duplex) stainless steels
— Corrosion test in nitric acid medium by measurement of loss
in mass (Huey test)
— Part 2: Ferritic, austenitic and ferritic-austenitic (duplex) stainless
steels — Corrosion test in media containing sulfuric acid
iii
©
ISO 3651-1:1998(E) ISO
Introduction
The term “intergranular corrosion test” denotes the corrosion test
carried out by means of preferential attack of the grain boundaries.
Austenitic and ferritic-austenitic (duplex) stainless steels may be
subject to such attack when they are held at a temperature between
about 500 °C and 1 000 °C. This heat cycle, which may provoke
sensitization to intergranular corrosion, may occur during hot
forming (forging, rolling) as the result of incorrect solution treatment
or during a welding operation.
NOTE —  Intergranular corrosion in nitric acid may be associated with one or
more of the following:
— precipitation of chromium carbides;
— precipitation of intermetallic compounds such as sigma phase, in
molybdenum-bearing grades;
— segregation of impurity elements to the grain boundaries.
The interpretation of the result (for example, maximum rate of
corrosion) shall form the subject of an agreement between the
interested parties.
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©
INTERNATIONAL STANDARD  ISO ISO 3651-1:1998(E)
Determination of resistance to intergranular corrosion of stainless
steels —
Part 1:
Austenitic and ferritic-austenitic (duplex) stainless steels — Corrosion
test in nitric acid medium by measurement of loss in mass (Huey test)
1 Scope
This part of ISO 3651 specifies a method for the determination of the resistance to intergranular
corrosion of austenitic and ferritic-austenitic (duplex) stainless steels in a nitric acid medium by
measurement of the loss in mass (Huey test). It also specifies the purpose which may be assigned to
the test.
The method is applicable only to austenitic and ferritic-austenitic (duplex) stainless steels supplied in the
form of rolled or forged products, tubes and cast products and intended for use in a strongly oxidizing
medium (for example, relatively concentrated nitric acid). In general the Huey test should not be used for
grades containing molybdenum unless the material tested is to be used in nitric acid service.
NOTE —  It is important to note that the result of the corrosion test is only strictly valid for the corrosive medium used in the
test. It constitutes a basis for estimating the resistance to intergranular corrosion but may not be used to check resistance to
other forms of corrosion (general corrosion, pitting, stress corrosion, etc.). It is necessary for the user to adapt the specified
corrosion test to the use which will be made of the alloy. This test should, in no
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