EN ISO 11782-2:2008
(Main)Corrosion of metals and alloys - Corrosion fatigue testing - Part 2: Crack propagation testing using precracked specimens (ISO 11782-2:1998)
Corrosion of metals and alloys - Corrosion fatigue testing - Part 2: Crack propagation testing using precracked specimens (ISO 11782-2:1998)
Describes the fracture mechanics method of determining the crack growth rates of pre-existing cracks under cyclic loading in a controlled environment and the measurement of the treshold stress intensity factor range for crack growth below which the rate of crack advance falls below some defined limit agreed between parties. This part provides guidance and instruction on corrosion fatigue testing of metals and alloys in aqueous or gaseous environments.
Korrosion von Metallen und Legierungen - Prüfung der Schwingungskorrosion - Teil 2: Rissausbreitungsprüfung an angerissenen Proben (ISO 11782-2:1998)
1.1 Dieser Teil von ISO 11782 beschreibt ein Verfahren der Bruchmechanik zur Bestimmung der Wachs¬tumsgeschwindigkeiten bereits vorhandener Anrisse unter wechselnder Beanspruchung in einer kontrollierten Umgebung und Messung des für den Spannungsintensitätsfaktor beim Risswachstum kritischen Bereichs, den die Rissausbreitungsgeschwindigkeit nicht erreicht, wenn eine zwischen den Beteiligten vereinbarte Grenze unterschritten wird.
1.2 Der vorliegende Teil von ISO 11782 bietet einen Leitfaden und Anleitungen für die Schwingungs¬korrosionsprüfung von Metallen und Legierungen in wässrigen oder gasförmigen Korrosionsmedien
Corrosion des métaux et alliages - Essais de fatigue-corrosion - Partie 2: Essais d'amorce de rupture sur des éprouvettes préfissurées (ISO 11782-2:1998)
La présente partie de l'ISO 11782 décrit une méthode reposant sur la mécanique de la rupture, permettant de déterminer les vitesses de propagation de fissures préexistantes sous chargement cyclique en milieu contrôlé et de mesurer la plage de facteur d'intensité de contrainte limite pour la propagation de fissure au-dessous de laquelle la vitesse de progression de la fissure devient inférieure à une limite définie convenue entre les parties. La présente partie de l'ISO 11782 donne des indications et des instructions sur les essais de fatigue-corrosion des métaux et des alliages en milieux aqueux ou gazeux.
Korozija kovin in zlitin - Ugotavljanje pokanja zaradi korozijske utrujenosti - 2. del: Preskus za ugotavljanje napredovanja razpok z vzorci z umetno razpoko (ISO 11782-2:1998)
Opisuje metodo lomne mehanike za določevanje hitrosti širjenja že obstoječih razpok pod ciklično obremenitvijo v nadzorovanem okolju in merjenje mejne vrednosti koeficienta lomne žilavosti za širjenje razpok, pod katero stopnja napredovanja razpok pade pod določeno mejo, dogovorjeno med strankama. Ta del podaja smernice in navodila za ugotavljanje pokanja zaradi korozijske utrujenosti za kovine in zlitine v vodnem ali plinastem okolju.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2008
1DGRPHãþD
SIST ISO 11782-2:1999
Korozija kovin in zlitin - Ugotavljanje pokanja zaradi korozijske utrujenosti - 2. del:
Preskus za ugotavljanje napredovanja razpok z vzorci z umetno razpoko (ISO
11782-2:1998)
Corrosion of metals and alloys - Corrosion fatigue testing - Part 2: Crack propagation
testing using precracked specimens (ISO 11782-2:1998)
Korrosion von Metallen und Legierungen - Prüfung der Schwingungskorrosion - Teil 2:
Rissausbreitungsprüfung an angerissenen Proben (ISO 11782-2:1998)
Corrosion des métaux et alliages - Essais de fatiguecorrosion - Partie 2: Essais d'amorce
de rupture sur des éprouvettes préfissurées (ISO 11782-2:1998)
Ta slovenski standard je istoveten z: EN ISO 11782-2:2008
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 11782-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2008
ICS 77.060
English Version
Corrosion of metals and alloys - Corrosion fatigue testing - Part
2: Crack propagation testing using precracked specimens (ISO
11782-2:1998)
Corrosion des métaux et alliages - Essais de fatigue- Korrosion von Metallen und Legierungen - Prüfung der
corrosion - Partie 2: Essais d'amorce de rupture sur des Schwingungskorrosion - Teil 2: Rissausbreitungsprüfung an
éprouvettes préfissurées (ISO 11782-2:1998) angerissenen Proben (ISO 11782-2:1998)
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,
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Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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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 11782-2:2008: E
worldwide for CEN national Members.
Contents Page
Foreword.3
Foreword
The text of ISO 11782-2:1998 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
11782-2:2008 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 11782-2:1998 has been approved by CEN as a EN ISO 11782-2:2008 without any
modification.
INTERNATIONAL ISO
STANDARD 11782-2
First edition
1998-07-15
Corrosion of metals and alloys — Corrosion
fatigue testing —
Part 2:
Crack propagation testing using precracked
specimens
Corrosion des métaux et alliages — Essais de fatigue-corrosion —
Partie 2: Essais d'amorce de rupture sur des éprouvettes préfissurées
A
Reference number
ISO 11782-2:1998(E)
ISO 11782-2:1998(E)
Contents Page
1 Scope . 1
2 Normative reference . 1
3 Definitions . 1
4 Test. 3
Principle of corrosion fatigue crack propagation testing .
4.1 3
4.2 Specimens for corrosion fatigue crack propagation testing 4
5 Apparatus . 5
6 Fatigue precracking . 6
7 Test conditions . 7
Test procedure .
8 9
9 Test report . 11
Annex A (informative) Information on methods for measuring
crack lengths . 13
© 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 11782-2:1998(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 11782-2 was prepared by Technical Committee
ISO/TC 158, 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 11782-2:1998(E) ISO
Introduction
Crack propagation testing employs precracked specimens to provide
information on the threshold conditions and on rates of corrosion fatigue
crack growth. These data can be used in the design and evaluation of
engineering structures where corrosion fatigue crack growth can dominate
component life.
Because of the need to maintain elastically constrained conditions at the
crack tip, the precracked specimens used for crack propagation tests are
not suitable for the evaluation of thin products such as sheet or wire and
are generally used for thicker products including plate, bar and forgings.
They can also be used for 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
especially with regard to material, environmental and stressing
considerations.
iv
©
INTERNATIONAL STANDARD ISO ISO 11782-2:1998(E)
Corrosion of metals and alloys — Corrosion fatigue testing —
Part 2:
Crack propagation testing using precracked specimens
1 Scope
1.1 This part of ISO 11782 describes the fracture mechanics method of determining the crack growth rates of pre-
existing cracks under cyclic loading in a controlled environment and the measurement of the threshold stress
intensity factor range for crack growth below which the rate of crack advance falls below some defined limit agreed
between parties.
1.2 This part of ISO 11782 provides guidance and instruction on corrosion fatigue testing of metals and alloys in
aqueous or gaseous environments.
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 force, P: Force applied to the specimen considered positive when its direction is such as to cause the crack
faces to move apart.
3.3 maximum force, P : Algebraic maximum value of force during a loading cycle.
max
3.4 minimum force, P : Algebraic minimum value of force during a loading cycle.
min
3.5 Difference between the algebraic maximum and minimum values of the force.
force range, DP:
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ISO
ISO 11782-2:1998(E)
3.6 stress intensity factor, K : Function of applied load, crack length and specimen geometry having dimensions
I
1/2
of stress (length) which uniquely defines the elastic stress field intensification at the tip of a crack subjected to
opening mode displacements (mode I).
NOTE — It has been found that stress intensity factors, calculated assuming that specimens respond purely elastically,
correlate the behaviour of real cracked bodies provided that the size of the zone of plasticity at the crack tip is small compared
to the crack length and the length of the uncracked ligament. In this standard, mode I is assumed and the subscript I is implied
everywhere.
3.7 maximum stress intensity factor, K , in fatigue: Highest algebraic value of the stress intensity factor in a
max
cycle corresponding to the maximum load.
3.8 minimum stress intensity factor, K , in fatigue: Lowest algebraic value of the stress intensity factor in a
min
cycle.
NOTE — This value corresponds to the minimum load when the stress ratio, R, is greater than zero and is set equal to zero
when R is less than or equal to zero.
3.9 range of stress intensity factor, DK, in fatigue: Algebraic difference between the maximum and minimum
stress intensity factors in a cycle:
DKK=−K
max min
3.10 threshold stress intensity factor range, DK , in fatigue: Value of the stress intensity factor range below
th
which the rate of crack advance becomes insignificant for the application.
3.11 stress ratio, R, in fatigue loading: Algebraic ratio of the minimum and maximum force in a cycle
P K
min min
R==
P K
max max
3.12 cycle: 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.
3.13 fatigue crack growth rate, da/dN: Rate of crack extension caused by fatigue loading and expressed in
terms of crack extension per cycle.
3.14 stress intensity factor coefficient, Y: Factor derived from the stress analysis for a particular specimen
geometry which relates the stress intensity factor for a given crack length to the load and specimen dimensions.
3.15 plane strain fracture toughness, K : The critical value of K at which the first significant environmentally
lc
independent extension of the crack occurs under the influence of rising stress intensity under conditions of high
constraint to plastic deformation.
3.16 specimen orientation: The fracture plane of the specimen identified in terms of firstly the direction of
stressing and secondly the direction of crack growth expressed with respect to three reference axes. These are
identified by the letters X, Y and Z.
where
Z is coincident with the main working force employed during manufacture of the material (short-transverse
axis);
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ISO
ISO 11782-2:1998(E)
X is coincident with the direction of grain flow (longitudinal axis);
Y is normal to the X and Z axes (see figure 1).
3.17 crack length, a: Effective crack length measured from the crack tip to either the mouth of the notch or the
loading point axis depending on the specimen geometry.
3.18 specimen width, W: Effective width of the specimen measured from the back face to either the face
containing the notch or the loading plane depending on the specimen geometry.
3.19 waveform: Shape of the peak-to-peak variation of load as a function of time.
3.20 cyclic frequency: Number of cycles per unit time, usually expressed in terms of cycles per second (Hz).
4 Test
4.1 Principle of corrosion fatigue crack propagation testing
A fatigue pre-crack is induced in a notched speci
...
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