EN ISO 11782-1:2008
(Main)Corrosion of metals and alloys - Corrosion fatigue testing - Part 1: Cycles to failure testing (ISO 11782-1:1998)
Corrosion of metals and alloys - Corrosion fatigue testing - Part 1: Cycles to failure testing (ISO 11782-1:1998)
Provides guidance and instruction on corrosion fatigue testing of metals and alloys in aqueous or gaseous environments and is concerned with cycles to failure testing.
Korrosion von Metallen und Legierungen - Prüfung der Schwingungskorrosion - Teil 1: Prüfung unter Anwendung von Bruch-Schwingspielen (ISO 11782-1:1998)
1.1 Diese Internationale Norm enthält einen Leitfaden und Anleitungen für die Prüfung der Schwingungs¬korrosion von Metallen und Legierungen in wässrigen oder gasförmigen Korrosionsmedien; es werden Prüfungen mit Schwingspielen bis zum Bruch der Proben durchgeführt. Die Rissausbreitungsprüfung wird in ISO 11782 2 behandelt.
1.2 Ein Korrosionsmedium oder eine auf andere Weise chemische aktive Umgebung kann die Auslösung von Daueranrissen in Metallen und Legierungen fördern und die Rissausbreitungsgeschwindigkeit dieser Daueranrisse erhöhen. Die Vorgänge bei der Schwingungskorrosion sind nicht auf bestimmte Systeme Metall/Korrosionsmedium begrenzt; für alle Kombinationen von Beanspruchung und Korrosionsmedium können zuverlässige Abschätzungen der Lebensdauer nur mit den Daten durchgeführt werden, die bei Laboratoriumsprüfungen ermittelt wurden.
1.3 Diese Internationale Norm ist nicht zur Anwendung für die Prüfung der Schwingungskorrosion von Bauteilen oder Produktionsteilen vorgesehen, obwohl viele der allgemeinen Grundsätze gelten.
Corrosion des métaux et alliages - Essais de fatigue-corrosion - Partie 1: Essais cycliques à la rupture (ISO 11782-1:1998)
La présente partie de l'ISO 11782 donne des indications et des instructions sur les essais de fatigue-corrosion des métaux et alliages dans des environnements aqueux ou gazeux et concerne les essais cycliques à la rupture. Les essais d'amorce de rupture sont pris en compte dans l'ISO 11782-2. Les environnements corrosifs ou autrement actifs chimiquement peuvent provoquer l'amorce de fissures par la fatigue des métaux et alliages et augmenter la vitesse de propagation de fissures par la fatigue. Les procédés de fatigue-corrosion ne sont pas limités à des systèmes environ nement/métal spécifiques; des estimations fiables de résistance à la fatigue pour toutes les combinaisons de chargement et d'environnement ne peuvent être réalisées sans données provenant des essais de laboratoire. La présente partie de l'ISO 11782 n'est pas destinée à être appliquée à des essais de fatigue-corrosion de composants ou de pièces; cependant, beaucoup des principes généraux s'appliquent.
Korozija kovin in zlitin - Ugotavljanje pokanja zaradi korozijske utrujenosti - 1. del: Število ciklov do končne porušitve (ISO 11782-1:1998)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2008
.RUR]LMDNRYLQLQ]OLWLQ8JRWDYOMDQMHSRNDQMD]DUDGLNRUR]LMVNHXWUXMHQRVWLGHO
âWHYLORFLNORYGRNRQþQHSRUXãLWYH ,62
Corrosion of metals and alloys - Corrosion fatigue testing - Part 1: Cycles to failure
testing (ISO 11782-1:1998)
Korrosion von Metallen und Legierungen - Prüfung der Schwingungskorrosion - Teil 1:
Prüfung unter Anwendung von Bruch-Schwingspielen (ISO 11782-1:1998)
Corrosion des métaux et alliages - Essais de fatiguecorrosion - Partie 1: Essais cycliques
a la rupture (ISO 11782-1:1998)
Ta slovenski standard je istoveten z: EN ISO 11782-1:2008
ICS:
77.060 Korozija kovin Corrosion of metals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN ISO 11782-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2008
ICS 77.060
English Version
Corrosion of metals and alloys - Corrosion fatigue testing - Part
1: Cycles to failure testing (ISO 11782-1:1998)
Corrosion des métaux et alliages - Essais de fatigue- Korrosion von Metallen und Legierungen - Prüfung der
corrosion - Partie 1: Essais cycliques à la rupture (ISO Schwingungskorrosion - Teil 1: Prüfung unter Anwendung
11782-1:1998) von Bruch-Schwingspielen (ISO 11782-1:1998)
This European Standard was approved by CEN on 21 March 2008.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate 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 Management Centre or to any CEN member.
This European 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 Management Centre has the same status as the
official versions.
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: rue de Stassart, 36 B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11782-1:2008: E
worldwide for CEN national Members.
Contents Page
Foreword.3
Foreword
The text of ISO 11782-1:1998 has been prepared by Technical Committee ISO/TC 156 “Corrosion of metals
and alloys” of the International Organization for Standardization (ISO) and has been taken over as EN ISO
11782-1:2008 by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” the secretariat of
which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by October 2008, and conflicting national standards shall be withdrawn at
the latest by October 2008.
Attention is drawn to the possibility that some of the elements of 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.
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, 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 the United Kingdom.
Endorsement notice
The text of ISO 11782-1:1998 has been approved by CEN as a EN ISO 11782-1:2008 without any
modification.
INTERNATIONAL ISO
STANDARD 11782-1
First edition
1998-07-15
Corrosion of metals and alloys — Corrosion
fatigue testing —
Part 1:
Cycles to failure testing
Corrosion des métaux et alliages — Essais de fatigue-corrosion —
Partie 1: Essais cycliques à la rupture
A
Reference number
ISO 11782-1:1998(E)
ISO 11782-1:1998(E)
Contents Page
1 Scope . 1
2 Normative reference . 1
3 Definitions . 1
4 Test. 3
Principle .
4.1 3
4.2 Specimens . 3
4.3 Environmental considerations. 8
4.4 Stressing considerations. 8
5 Apparatus . 9
Procedure .
6 9
7 Test report . 10
Annex A (informative) Bibliography . 12
© 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 11782-1:1998(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 11782-1 was prepared by Technical Committee
ISO/TC 156, Corrosion of metals and alloys.
ISO 11782 consists of the following parts, under the general title Corrosion
of metals and alloys — Corrosion fatigue testing
— Part 1: Cycles to failure testing
— Part 2: Crack propagation testing using precracked specimens
Annex A of this part of ISO 11782 is for information only.
iii
©
ISO 11782-1:1998(E) ISO
Introduction
The study of cycles to failure testing uses plain or notched specimens to
provide data on the intrinsic corrosion fatigue crack like behaviour of a
metal or alloy and can be used to develop criteria for engineering design to
prevent fatigue failures.
The study of cycles to failure can be applied to a wide variety of product
forms including plate, rod, wire, sheet and tubes as well as to parts joined
by welding.
The results of corrosion fatigue testing are suitable for direct application
only when the service conditions exactly parallel the test conditions es-
pecially with regard to material, environmental and stressing consider-
ations. The combination of material/load/environmental may not be directly
comparable to the application. For these cases engineering judgement
must be applied.
iv
©
INTERNATIONAL STANDARD ISO ISO 11782-1:1998(E)
Corrosion of metals and alloys — Corrosion fatigue testing —
Part 1:
Cycles to failure testing
1 Scope
1.1 This International Standard provides guidance and instruction on corrosion fatigue testing of metals and alloys
in aqueous or gaseous environments and is concerned with cycles to failure testing. Crack propagation testing is
considered in ISO 11782-2.
1.2 Corrosive or otherwise chemically active environments can promote the initiation of fatigue cracks in metals
and alloys and increase the rate of fatigue crack propagation. Corrosion fatigue processes are not limited to specific
metal/environment systems and reliable estimates of fatigue life for all combinations of loading and environment
cannot be made without data from laboratory tests.
1.3 This International Standard is not intended for application to corrosion fatigue testing of components or parts;
nevertheless many of the general principles will apply.
2 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this part of
ISO 11782. At the time of publication, the edition indicated was valid. All standards are subject to revision, and
parties to agreements based on this part of ISO 11782 are encouraged to investigate the possibility of applying the
most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid
International Standards.
ISO 7539-1:1987, Corrosion of metals and alloys — Stress corrosion testing — Part 1: General guidance on testing
procedures.
3 Definitions
For the purposes of this part of ISO 11782, the following definitions apply.
3.1 corrosion fatigue: Process involving conjoint corrosion and alternating straining of the metal, often leading to
cracking.
NOTE — Corrosion fatigue may occur when a metal is subjected to cyclic straining in a corrosive environment.
3.2 stress amplitude, S , in fatigue loading: One half of the range of a cycle (also known as the alternating
a
stress):
SS-
max min
S =
a
©
ISO
ISO 11782-1:1998(E)
3.3 mean stress, S , in fatigue loading: Algebraic average of the maximum and minimum stresses in constant
m
amplitude loading or of individual cycles in spectrum loading:
SS+
max
min
S =
m
3.4 maximum stress, S , in fatigue loading: That stress having the highest algebraic value:
max
SS=+S
max m a
3.5 minimum stress, S , in fatigue loading: That stress having the lowest algebraic value:
min
SS=−S
min ma
3.6 stress ratio, R, in fatigue loading: Algebraic ratio of the minimum and maximum stress of a cycle:
S
min
R =
S
max
NOTE — The stress ratio, R, is equal to the load ratio P /P , where P and P are the minimum and maximum loads in
min max min max
the cycle, respectively.
3.7 S-N diagram: Plot of stress against the number of cycles to failure.
The stress can be the maximum stress, S , minimum stress, S , stress range, DS or S , or alternating stress, S .
max min r a
The diagram indicates the S-N relationship for a specified value of S , R and a specified probability of survival. For
m
N, a log scale is almost always used. For S, a linear scale or a log scale is used.
3.8 fatigue notch factor, K : Ratio of the fatigue strength of a specimen with no stress concentrator to that of a
f
specimen with a stress concentrator for the same percent survival at N cycles for the same loading and
environmental conditions.
NOTE — In specifying K , it is necessary to specify the geometry and the values of stress amplitude, mean stress and N for
f
which it is computed.
3.9 stress concentration factor, K: Ratio of the greatest stress in the region of a notch or other stress
t
concentrator as determined by the theory of elasticity to the corresponding nominal stress.
K becomes invalid when the stress at the notch root exceeds the yield strength.
t
3.10 cycle (in fatigue): Smallest segment of the load- or stress-time function which is repeated periodically. The
terms fatigue cycle, load cycle and stress cycle are also commonly used.
3.11 waveform: Shape of the peak-to-peak variation of load as a function of time.
3.12 cyclic frequency, f: Number of cycles per unit time, usually expressed in terms of cycles per second (Hz).
3.13 fatigue strength at N load cycles, S : Value of stress for failure at exactly N load cycles as determined
N
from an S-N diagram. The value of S thus determined is subject to the same conditions as those that apply to the
N
S-N diagram.
NOTES
1 The value of S is also known as the median fatigue strength for N cycles.
N
2 In a corrosive environment the fatigue strength is likely to be reduced compared with that in air.
©
ISO
ISO 11782-1:1998(E)
3.14 fatigue strength limit, S : Limiting value of the median fatigue strength as the fatigue life, N, becomes very
f
large. Most materials and environments preclude the attainment of well defined fatigue limits.
4 Test
4.1 Principle
In the presence of an aggressive environment the fatigue strength of a metal or alloy is reduced to an extent which
depends on the nature of the environment and the test conditions. For example, the well-defined fatigue strength
limit observed for steels in air may no longer be evident as illustrated in figure 1. Interpretation of results is then
based on the assumption of an acceptable life of the component.
The test involves subjecting a series of specimens to the number of stress cycles required for a fatigue crack to
initiate and grow large enough to cause failure during exposure to a corrosive or otherwise chemically active
environment at progressively smaller alternating stresses in order to define either the fatigue strength at N cycles,
S , from an S-N diagram or the fatigue strength limit as the fatigue life becomes very large.
N
The test is used to determine the effect of environment, material, geometry, surface condition, stress, etc, on the
corrosion fatigue resistance of metals or alloys subjected to applied stress for relatively large number
...
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