SIST EN 16602-70-37:2015
(Main)Space product assurance - Determination of the susceptibility of metals to stress-corrosion cracking
Space product assurance - Determination of the susceptibility of metals to stress-corrosion cracking
This document defines the requirements for the evaluation of the susceptibility of the SCC resistance.
It defines the preferred way to determine the susceptibility of metals and weldments to stress-corrosion cracking by alternate immersion
in 3.5 % sodium chloride under constant load.
The results obtained from test programmes made according to this specification are used to classify alloys, weldments and their individual heat treatment conditions. When sufficient stress-corrosion data exists, the alloy designations can be submitted for inclusion into the
various tables contained in ECSS-Q-ST-70-36.
In this document, the supplier is identified as the entity that performs the test.
This standard may be tailored for the specific characteristics and constrains of a space project in conformance with ECSS-S-ST-00.
Raumfahrtproduktsicherung - Bestimmung der Anfälligkeit von Metallen für Spannungsrisskorrosion
Assurance produit des projets spatiaux - Détermination de la susceptibilité des métaux à la fissuration par corrosion sous contrainte
La présente norme définit les exigences relatives aux essais mécaniques effectués sur les matériaux métalliques utilisés lors de la fabrication du matériel spatial.
La présente norme fixe les exigences relatives aux méthodes d'essai les plus pertinentes utilisées pour évaluer les propriétés de traction, de fatigue et de rupture des matériaux métalliques. Elle ne passe pas en revue toutes les méthodes d'essai utilisées pour évaluer les propriétés mécaniques de ces matériaux.
En outre, la présente norme définit les exigences relatives à l'évaluation, à la présentation et à la communication des résultats des essais.
La présente norme peut être adaptée aux caractéristiques et contraintes spécifiques d'un projet spatial, conformément à l'ECSS-S-ST-00.
Zagotavljanje varnih proizvodov v vesoljski tehniki - Ugotavljanje občutljivosti kovin za stresne korozijske razpoke
Ta dokument določa zahteve za oceno občutljivosti odpornosti na stresne korozijske razpoke. Določa prednostni način za ugotavljanje občutljivosti kovin in zvarov za stresne korozijske razpoke z izmeničnim potapljanjem v 3,5-odstotno raztopino natrijevega klorida pod trajno obremenitvijo. Rezultati, pridobljeni na podlagi preskusnih programov, izvedenih v skladu s to specifikacijo, se uporabljajo za razvrščanje zlitin, zvarov in njihovih posameznih pogojev toplotne obdelave. Ko obstajajo zadostni podatki v zvezi s stresno korozijo, je mogoče oznake zlitin predložiti za vključitev v različne preglednice iz standarda ECSS-Q-ST-70-36. V tem dokumentu je dobavitelj opredeljen kot subjekt, ki izvede preskus. Ta standard se lahko prilagodi posameznim lastnostim in omejitvam vesoljskega projekta v skladu s standardom ECSS-S-ST-00.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 16602-70-37:2015
01-januar-2015
=DJRWDYOMDQMHYDUQLKSURL]YRGRYYYHVROMVNLWHKQLNL8JRWDYOMDQMHREþXWOMLYRVWL
NRYLQ]DVWUHVQHNRUR]LMVNHUD]SRNH
Space product assurance - Determination of the susceptibility of metals to stress-
corrosion cracking
Raumfahrtproduktsicherung - Bestimmung der Anfälligkeit von Metallen für
Spannungsrisskorrosion
Assurance produit des projets spatiaux - Détermination de la susceptibilité des métaux à
la fissuration par corrosion sous contrainte
Ta slovenski standard je istoveten z: EN 16602-70-37:2014
ICS:
49.140 Vesoljski sistemi in operacije Space systems and
operations
77.060 Korozija kovin Corrosion of metals
SIST EN 16602-70-37:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 16602-70-37:2015
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SIST EN 16602-70-37:2015
EUROPEAN STANDARD
EN 16602-70-37
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2014
ICS 49.025.01; 49.140
English version
Space product assurance - Determination of the susceptibility of
metals to stress-corrosion cracking
Assurance produit des projets spatiaux - Détermination de Raumfahrtproduktsicherung - Bestimmung der Anfälligkeit
la susceptibilité des métaux à la fissuration par corrosion von Metallen für Spannungsrisskorrosion
sous contrainte
This European Standard was approved by CEN on 25 October 2014.
CEN and CENELEC 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-CENELEC Management Centre or to any CEN and CENELEC
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 and CENELEC member into its own language and notified to the CEN-CENELEC Management Centre
has the same status as the official versions.
CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia,
Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
CEN-CENELEC Management Centre:
Avenue Marnix 17, B-1000 Brussels
© 2014 CEN/CENELEC All rights of exploitation in any form and by any means reserved Ref. No. EN 16602-70-37:2014 E
worldwide for CEN national Members and for CENELEC
Members.
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SIST EN 16602-70-37:2015
EN 16602-70-37:2014 (E)
Table of contents
Foreword . 5
1 Scope . 6
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 9
3.1 Terms defined in other standards . 9
3.2 Terms specific to the present standard . 9
3.3 Abbreviated terms. 10
3.4 Symbols . 11
4 Principles . 12
4.1 Overview . 12
4.2 Tensile test . 12
4.3 Fracture toughness test . 12
4.3.1 Overview . 12
4.3.2 Determination of fracture toughness using the K test method . 12
Ic
4.3.3 Determination of fracture toughness using the J test method . 13
Ic
4.3.4 Characterization of fracture toughness using the R-curve test method . 13
4.3.5 Characterization of fracture toughness using the CTOD test method . 13
4.4 Fatigue test . 14
4.4.1 General . 14
4.4.2 Force controlled constant amplitude axial fatigue test . 14
4.4.3 Strain-controlled fatigue test . 14
4.5 Fatigue crack propagation test . 14
4.5.1 Stable crack growth rate. 14
4.5.2 Crack propagation threshold . 15
4.6 Fracture and fatigue test in special environment . 15
4.7 Stress corrosion cracking test . 15
4.7.1 Overview . 15
4.7.2 Stress corrosion cracking test using smooth specimens . 15
4.7.3 Stress corrosion cracking test using pre-cracked specimens . 16
2
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EN 16602-70-37:2014 (E)
4.8 Creep test . 16
4.9 Test results presentation. 16
5 Requirements . 17
5.1 Customer agreement . 17
5.2 Tensile testing . 17
5.2.1 General . 17
5.2.2 Tensile testing of weldments . 17
5.3 Fracture toughness test . 18
5.3.1 K test method . 18
Ic
5.3.2 J test method . 18
Ic
5.3.3 R-curve test method . 18
5.3.4 CTOD test method . 18
5.4 Fatigue test . 19
5.4.1 Force controlled constant amplitude axial fatigue test . 19
5.4.2 Strain-controlled fatigue test . 19
5.5 Fatigue crack propagation test . 20
5.5.1 Determination of fatigue crack growth rate . 20
5.5.2 Determination of a fatigue crack propagation threshold . 20
5.6 Fracture and fatigue tests in special environments . 21
5.7 Stress corrosion cracking test . 21
5.7.1 Stress corrosion cracking test using smooth specimens . 21
5.7.2 Stress corrosion cracking test using pre-cracked specimens . 21
5.8 Creep test . 21
5.9 Evaluation of test results . 21
5.10 Storage . 22
5.11 Reporting . 22
5.12 Quality assurance . 22
5.12.1 General . 22
5.12.2 Calibration . 22
5.12.3 Quality control of raw materials . 23
5.12.4 Nonconformance . 23
5.12.5 Traceability and records . 23
Annex A (normative) Request for mechanical testing of materials – DRD . 24
Annex B (normative) Proposal for mechanical testing of materials – DRD . 26
Annex C (normative) Report of mechanical testing of materials – DRD . 28
3
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EN 16602-70-37:2014 (E)
Annex D (informative) References . 31
Bibliography . 32
4
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SIST EN 16602-70-37:2015
EN 16602-70-37:2014 (E)
Foreword
This document (EN 16602-70-37:2014) has been prepared by Technical
Committee CEN/CLC/TC 5 “Space”, the secretariat of which is held by DIN.
This standard (EN 16602-70-37:2014) originates from ECSS-Q-ST-70-45C.
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 April 2015,
and conflicting national standards shall be withdrawn at the latest by April
2015.
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.
This document has been prepared under a mandate given to CEN by the
European Commission and the European Free Trade Association
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, Croatia, Cyprus, Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
5
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SIST EN 16602-70-37:2015
EN 16602-70-37:2014 (E)
1
Scope
This Standard specifies requirements for mechanical testing of metallic
materials to be used in the fabrication of spacecraft hardware.
This Standard establishes the requirements for most relevant test methods
carried out to assess the tensile, fatigue and fracture properties of metallic
materials. It does not give a complete review of all the existing test methods for
the evaluation of mechanical properties of metallic materials.
Furthermore, this Standard specifies requirements for the evaluation,
presentation and reporting of test results.
This standard may be tailored for the specific characteristic and constrains of a
space project in conformance with ECSS-S-ST-00.
6
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EN 16602-70-37:2014 (E)
2
Normative references
The following normative documents contain provisions which, through
reference in this text, constitute provisions of this ECSS Standard. For dated
references, subsequent amendments to, or revision of any of these publications
do not apply, However, parties to agreements based on this ECSS Standard are
encouraged to investigate the possibility of applying the more recent editions of
the normative documents indicated below. For undated references, the latest
edition of the publication referred to applies.
EN reference Reference in text Title
EN 16601-00-01 ECSS-S-ST-00-01 ECSS system — Glossary of terms
EN 16602-10-09 ECSS-Q-ST-10-09 Space product assurance — Nonconformance control
system
EN 16602-70 ECSS-Q-ST-70 Space product assurance — Materials, mechanical
parts and processes
EN 16602-70-37 ECSS-Q-ST-70-37 Space product assurance — Determination of the
susceptibility of metals to stress-corrosion cracking
EN 16602-70-46 ECSS-Q-ST-70-46 Space product assurance — Requirements for
manufacturing and procurement of threaded fasteners
ASTM E 139 Standard test methods for conducting creep, creep-
rupture, and stress-rupture tests of metallic materials
ASTM E 399 Standard test method for plane-strain fracture
toughness of metallic materials
ASTM E 466 Standard practice for conducing force controlled
constant amplitude axial fatigue tests of metallic
materials
ASTM E 561 Standard practice for R-curve determination
ASTM E 606 Standard practice for strain-controlled fatigue testing
ASTM E 647 Standard test method for measurement of fatigue
crack growth rates
ASTM E 739 Standard practice for statistical analysis of linear or
linarized stress-life (S-N) and strain-life (e-N) fatigue
data
7
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ASTM E 1290 Standard test method for crack-tip opening displace-
ment (CTOD) fracture toughness measurement
ASTM E 1820 Standard test method for measurement of fracture
toughness
EN 10002-1 Metallic materials — Tensile testing — Part 1: Method
of test at ambient temperature
EN 10002-2 Metallic materials — Tensile testing — Part 2:
Verification of the force measuring system of the
tensile testing machines
EN 10002-4 Metallic materials — Tensile testing — Part 4:
Verification of the extensometers used in uniaxial
testing
ESDU 96013:1996 Fracture toughness (KIc) values of some aluminium
alloys
ISO 7539-6:2003 Corrosion of metals and alloys — Stress corrosion
testing — Part 6: Preparation and use of pre-cracked
specimens for tests under constant load or constant
displacement
8
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SIST EN 16602-70-37:2015
EN 16602-70-37:2014 (E)
3
Terms, definitions and abbreviated terms
3.1 Terms defined in other standards
For the purpose of this Standard, the terms and definitions from
ECSS-S-ST-00-01 and ECSS-Q-ST-70 apply.
3.2 Terms specific to the present standard
3.2.1 crack tip plastic zone
plastically deformed region in a material adjacent to a crack tip
3.2.2 creep
time-dependent increase in strain in a material resulting from force
3.2.3 damage tolerance
in a material or structure, the capability to withstand stresses or loads in the
presence of defects
3.2.4 failure
condition generally caused by break or collapse so that a structural element can
no longer fulfil its purpose
3.2.5 fatigue
in a material, the failure phenomenon which results from repeated fluctuation
of stress
3.2.6 fracture toughness
inherent resistance of a material in the presence of a crack-like defect
3.2.7 finite life range
life range, in which all test pieces before a predetermined number of cycles fail
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SIST EN 16602-70-37:2015
EN 16602-70-37:2014 (E)
3.2.8 mechanical properties
those properties of a material that are associated with elastic and inelastic
reaction when force is applied, or that involve the relationship between stress
and strain
3.2.9 mechanical testing
determination of mechanical properties
3.2.10 raw material
material from which specimens are manufactured
3.2.11 specimen
representative fraction of material tested or analysed in order to determine
mechanical properties
3.2.12 transition range
-6 -7
predetermined number of cycles of stress cycles (typically 5 x 10 to 5 x 10
cycles), where failure as well as non-failure occur.
3.2.13 threaded fastener
device composed by a cylindrical screwed bar provided with a head and a
metal collar, screwed internally, to fit the cylindrical bar that is to hold parts
firmly together in an assembly
3.2.14 weld heat affected zone (HAZ)
portion of material in a welded joint whose microstructure and physical
properties are affected by the heat input during welding
3.3 Abbreviated terms
For the purpose of this Standard, the abbreviated terms from ECSS-S-ST-00-01
and the following apply:
Abbreviation Meaning
American Society for Testing and Materials
ASTM
European Committee for Standardization
CEN
crack tip opening displacement
CTOD
engineering sciences data unit
ESDU
heat affected zone
HAZ
International Organization for Standardization
ISO
nonconformance report
NCR
non-destructive inspection
NDI
raw material certificate
RMC
10
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SIST EN 16602-70-37:2015
EN 16602-70-37:2014 (E)
3.4 Symbols
Symbol Meaning
compact tension specimen
C(T)
J-integral
J
J-integral plane-strain fracture toughness
JIc
stress intensity factor
K
stress intensity plane-strain fracture toughness
KIc
maximum stress intensity factor
Kmax
opening mode of loading
Mode I
stress ratio
R
specimen stress ratio
Rsx
middle tension specimen
M(T)
crack growth rate
da/dn
stress intensity factor range
ΔK
fatigue crack propagation threshold
ΔKth
threshold stress intensity factor for susceptibility
KISCC
to stress corrosion cracking
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SIST EN 16602-70-37:2015
EN 16602-70-37:2014 (E)
4
Principles
4.1 Overview
This Standard specifies requirements to conduct tests in order to characterize
mechanical behaviour and properties of metallic materials. Selection criteria of
mechanical tests are based on the significance and use of each specified test
method. Test methods, which are covered in this Standard, are characterized in
the following paragraphs.
4.2 Tensile test
Tensile tests provide information on the strength and ductility of materials
under uniaxial tensile stresses. Test results can be used in comparing materials,
alloy development, design and quality control. The test method covers the
tension testing of metallic materials in any form at room temperature, and
specifically the methods determine yield strength, yield point elongation,
tensile strength, elongation and reduction of area.
4.3 Fracture toughness test
4.3.1 Overview
This test refers to methods to determine fracture toughness of metallic materials
using the following parameters: stress intensity factor (K), J-integral (J), R-curve
and crack tip opening displacement (CTOD). The fracture toughness
determined in accordance with this method is for opening mode (Mode I) of
loading.
4.3.2 Determination of fracture toughness using
the K test method
Ic
This method provides the measurement of crack-extension resistance at the
start of a crack extension for slow rates of loading and when the crack-tip
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plastic zone is small compared to both the crack size and to the specimen
dimension in the direction of the constraint.
The method covers the determination of linear elastic plane-strain fracture
toughness (KIc) of metallic materials by tests using a variety of fatigue-
precracked specimens.
4.3.3 Determination of fracture toughness using
the J test method
Ic
This method provides the measurement of crack-extension resistance near the
onset of stable crack extension for slow rates of loading and substantial plastic
deformation.
The method covers the determination of the J-integral plane-strain fracture
toughness (JIc) of metallic materials.
4.3.4 Characterization of fracture toughness
using the R-curve test method
This method provides a characterization of the resistance to fracture of metallic
materials during incremental slow stable crack extension and result from
growth of the plastic zone as the crack extends from a sharp notch. Materials
that can be tested for R-curve development are not limited by strength,
thickness, or toughness provided that specimens are of sufficient size to remain
predominantly elastic.
The method covers the determination of resistance to fracturing of metallic
materials by R-curves obtained by testing compact tension specimens C(T) or
middle tension specimens M(T).
4.3.5 Characterization of fracture toughness
using the CTOD test method
This test method provides a characterization of the fracture toughness of
metallic materials and is used for materials that exhibit a change from ductile to
brittle behaviour with decreasing temperature. This method is also used to
characterize the toughness of materials for which the properties and thickness
of interest preclude the determination of KIc fracture toughness in accordance
with ASTM E 399.
The specimen dimensions can affect the values of CTOD. For this reason
specimens of same dimensions are used when comparing test results.
The method covers the determination of critical crack tip opening displacement
(CTOD) values at one or more of several crack extension events. These CTOD is
used as measures of fracture toughness for metallic materials.
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EN 16602-70-37:2014 (E)
4.4 Fatigue test
4.4.1 General
Fatigue test refers to tests methods for the determination of fatigue strength of
metallic materials subjected to constant amplitude cycling loading.
4.4.2 Force controlled constant amplitude axial
fatigue test
The force controlled axial fatigue test is used to determine the effect of
variations in stress, material, geometry and surface condition on the fatigue
resistance of materials subjected to fatigue loading. The results can also be used
as a guideline for the selection of metallic materials for service under conditions
of repeated direct stress.
The method covers axial force controlled fatigue tests to obtain the fatigue
strength of materials in the fatigue regime, where the strains are predominately
elastic throughout the test.
4.4.3 Strain-controlled fatigue test
Strain-controlled fatigue is important for situations in which components or
portions of components undergo either mechanically or thermally induced
cyclic plastic strains that cause failure within relatively few cycles (i.e. fatigue
5
life < 10 cycles).
The method covers axial strain-controlled fatigue tests to obtain the fatigue
strength of materials in the fatigue regime where the strains are predominately
plastic.
4.5 Fatigue crack propagation test
4.5.1 Stable crack growth rate
Fatigue crack growth rate (da/dn) expressed as a function of crack tip stress
intensity factor range (∆K), characterizes a material’s resistance to stable crack
propagation under cyclic loading. Results from this test together with data on
toughness are used in the prediction of the damage tolerance behaviour
(typically the cycles or service period to grow a crack to a certain crack size, the
maximum permissible crack size and residual strength) and fatigue life
prediction for structural components.
The method covers the determination of stable crack growth rates from near-
threshold propagation regime to controlled crack propagation instability.
Results are expressed in terms of da/dn versus ∆K.
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SIST EN 16602-70-37:2015
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4.5.2 Crack propagation threshold
Although the fatigue-crack propagation threshold (∆Kth) is defined as the
asymptotic value of ∆K at which da/dn approaches zero, an operational, though
arbitrary, definition of ∆Kth is given for most materials. This value is defined as
∆K, which corresponds to a specified fatigue crack growth rate (typically for
-8
crack growth rates of 10 m/cycle or less).
It is found that the propagation threshold behaviour of long cracks can be
described in terms of stress ratio (R) as well as in terms of maximum stress
intensity Kmax, (see references [1], [2] and [3] in Annex D). From a practical point
of view, testing at constant Kmax allows to proceed faster compared to testing at
constant R, since load history effects are generally negligible. The approach is
based on the observation that for many alloys ∆Kth vs. Kmax relationships show a
quasi-linear dependency above certain Kmax values. Similarly, Kmax vs. R
relationships at low R values can be approximated by linear relations.
Under the assumption of linear dependence, ∆Kth vs. Kmax or Kmax vs. R,
relations for a material can be determined by a relatively low number of tests.
Accordingly the requirement section covers two methods to determine the
fatigue crack propagation threshold for metallic materials:
Determination of an operational value of ∆Kth) according to ASTM E 647.
Determination of (∆Kth) by testing at constant Kmax.
4.6 Fracture and fatigue test in special environment
Fatigue and crack propagation behaviour of metallic materials exposed to
gaseous or liquid environments can differ from that exhibited in air. Test results
obtained from fatigue and fracture tests in environments representative of the
service conditions are used to evaluate the influence of specific environments
on the material behaviour.
The method covers tests to determine the influence of environments
representative of service conditions on the fatigue and fracture behaviour of
metallic materials.
4.7 Stress corrosion cracking test
4.7.1 Overview
The test refers to methods for the determination of the susceptibility of metallic
materials to stress corrosion cracking.
4.7.2 Stress corrosion cracking test using smooth
specimens
The results of this tests are used to classify alloys, weldments and their
individual heat treatment conditions with respect to the material resistance
15
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SIST EN 16602-70-37:2015
EN 16602-70-37:2014 (E)
against stress corrosion cracking. When sufficient stress corrosion data exists
the alloy designation can be submitted for inclusion into relevant tables
contained in ECSS-Q-ST-70-36.
The method covers the determination of the susceptibility of metals and
weldments to stress corrosion cracking by alternate immersion in 3,5 % sodium
chloride water solution under constant load.
4.7.3 Stress corrosion cracking test using pre-
cracked specimens
This test method allows the determination of the threshold stress intensity
factor value for stress corrosion cracking KISCC, and the kinetics of crack
propagation.
The use of pre-cracked specimens acknowledges the fact that defects introduced
during manufacturing and subsequent services are always present in real
structures. Furthermore, the presence of such defects can cause a susceptibility
to stress corrosion cracking, which in some materials (e.g. titanium alloys) is not
always evident from tests conducted on smooth specimens.
This test method covers preparing and testing of pre-cracked specimens for
investigating susceptibility to stress corrosion cracking of metallic materials.
4.8 Creep test
The results of this test method are used to assess the load-carrying ability of a
material at high temperatures for limited deformations and as a function of
time. The test provides information to assess the suitability of materials for high
temperature structural applications.
The method covers the determination of the amount of deformation as a
function of time (creep test) and of the time for fracture to occur (rupture test) in
materials subjected to constant tensile forces at constant temperature.
4.9 Test results presentation
Before results obtained from mechanical tests can be applied with confidence,
allowable values are statistically determined. The applicability of statistical
methods to the evaluation of numerical results depends on:
• the number of tests performed on a specific material and test conditions,
which should be large enough to constitute a statistically sig
...
SLOVENSKI STANDARD
kSIST FprEN 16602-70-37:2014
01-september-2014
HREþXWOMLYRVWL=DJRWDYOMDQMHYDUQLKSURL]YRGRYYYHVROMVNLWHKQLNL8JRWDYOMDQM
NRYLQ]DVWUHVQHNRUR]LMVNHUD]SRNH
Space product assurance - Determination of the susceptibility of metals to stress-
corrosion cracking
Raumfahrtproduktsicherung - Bestimmung der Anfälligkeit von Metallen für
Spannungsrisskorrosion
Assurance produit des projets spatiaux - Détermination de la susceptibilité des métaux à
la fissuration par corrosion sous contrainte
Ta slovenski standard je istoveten z: FprEN 16602-70-37
ICS:
49.140 Vesoljski sistemi in operacije Space systems and
operations
77.060 Korozija kovin Corrosion of metals
kSIST FprEN 16602-70-37:2014 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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kSIST FprEN 16602-70-37:2014
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kSIST FprEN 16602-70-37:2014
EUROPEAN STANDARD
FINAL DRAFT
FprEN 16602-70-37
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2014
ICS 49.025.01; 49.140
English version
Space product assurance - Determination of the susceptibility of
metals to stress-corrosion cracking
Assurance produit des projets spatiaux - Détermination de Raumfahrtproduktsicherung - Bestimmung der Anfälligkeit
la susceptibilité des métaux à la fissuration par corrosion von Metallen für Spannungsrisskorrosion
sous contrainte
This draft European Standard is submitted to CEN members for unique acceptance procedure. It has been drawn up by the Technical
Committee CEN/CLC/TC 5.
If this draft becomes a European Standard, CEN and CENELEC 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.
This draft European Standard was established by CEN and CENELEC in three official versions (English, French, German). A version in any
other language made by translation under the responsibility of a CEN and CENELEC member into its own language and notified to the
CEN-CENELEC Management Centre has the same status as the official versions.
CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium, Bulgaria,
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Table of contents
Foreword . 5
1 Scope . 6
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 9
3.1 Terms defined in other standards . 9
3.2 Terms specific to the present standard . 9
3.3 Abbreviated terms. 10
3.4 Symbols . 11
4 Principles . 12
4.1 Overview . 12
4.2 Tensile test . 12
4.3 Fracture toughness test . 12
4.3.1 Overview . 12
4.3.2 Determination of fracture toughness using the K test method . 12
Ic
4.3.3 Determination of fracture toughness using the J test method . 13
Ic
4.3.4 Characterization of fracture toughness using the R-curve test method . 13
4.3.5 Characterization of fracture toughness using the CTOD test method . 13
4.4 Fatigue test . 14
4.4.1 General . 14
4.4.2 Force controlled constant amplitude axial fatigue test . 14
4.4.3 Strain-controlled fatigue test . 14
4.5 Fatigue crack propagation test . 14
4.5.1 Stable crack growth rate. 14
4.5.2 Crack propagation threshold . 15
4.6 Fracture and fatigue test in special environment . 15
4.7 Stress corrosion cracking test . 15
4.7.1 Overview . 15
4.7.2 Stress corrosion cracking test using smooth specimens . 15
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4.7.3 Stress corrosion cracking test using pre-cracked specimens . 16
4.8 Creep test . 16
4.9 Test results presentation. 16
5 Requirements . 17
5.1 Customer agreement . 17
5.2 Tensile testing . 17
5.2.1 General . 17
5.2.2 Tensile testing of weldments . 17
5.3 Fracture toughness test . 18
5.3.1 K test method . 18
Ic
5.3.2 J test method . 18
Ic
5.3.3 R-curve test method . 18
5.3.4 CTOD test method . 18
5.4 Fatigue test . 19
5.4.1 Force controlled constant amplitude axial fatigue test . 19
5.4.2 Strain-controlled fatigue test . 19
5.5 Fatigue crack propagation test . 20
5.5.1 Determination of fatigue crack growth rate . 20
5.5.2 Determination of a fatigue crack propagation threshold . 20
5.6 Fracture and fatigue tests in special environments . 21
5.7 Stress corrosion cracking test . 21
5.7.1 Stress corrosion cracking test using smooth specimens . 21
5.7.2 Stress corrosion cracking test using pre-cracked specimens . 21
5.8 Creep test . 21
5.9 Evaluation of test results . 21
5.10 Storage . 22
5.11 Reporting . 22
5.12 Quality assurance . 22
5.12.1 General . 22
5.12.2 Calibration . 22
5.12.3 Quality control of raw materials . 23
5.12.4 Nonconformance . 23
5.12.5 Traceability and records . 23
Annex A (normative) Request for mechanical testing of materials – DRD . 24
Annex B (normative) Proposal for mechanical testing of materials – DRD . 26
Annex C (normative) Report of mechanical testing of materials – DRD . 28
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Annex D (informative) References . 31
Bibliography . 32
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Foreword
This document (FprEN 16602-70-37:2014) has been prepared by Technical
Committee CEN/CLC/TC 5 “Space”, the secretariat of which is held by DIN
(Germany).
This document (FprEN 16602-70-37:2014) originates from ECSS-Q-ST-70-45C.
This document is currently submitted to the Unique Acceptance Procedure.
This document has been developed to cover specifically space systems and will
the-refore have precedence over any EN covering the same scope but with a
wider do-main of applicability (e.g. : aerospace).
5
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1
Scope
This Standard specifies requirements for mechanical testing of metallic
materials to be used in the fabrication of spacecraft hardware.
This Standard establishes the requirements for most relevant test methods
carried out to assess the tensile, fatigue and fracture properties of metallic
materials. It does not give a complete review of all the existing test methods for
the evaluation of mechanical properties of metallic materials.
Furthermore, this Standard specifies requirements for the evaluation,
presentation and reporting of test results.
This standard may be tailored for the specific characteristic and constrains of a
space project in conformance with ECSS-S-ST-00.
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2
Normative references
The following normative documents contain provisions which, through
reference in this text, constitute provisions of this ECSS Standard. For dated
references, subsequent amendments to, or revision of any of these publications
do not apply, However, parties to agreements based on this ECSS Standard are
encouraged to investigate the possibility of applying the more recent editions of
the normative documents indicated below. For undated references, the latest
edition of the publication referred to applies.
EN reference Reference in text Title
EN 16601-00-01 ECSS-S-ST-00-01 ECSS system — Glossary of terms
EN 16602-10-09 ECSS-Q-ST-10-09 Space product assurance — Nonconformance control
system
EN 16602-70 ECSS-Q-ST-70 Space product assurance — Materials, mechanical
parts and processes
EN 16602-70-37 ECSS-Q-ST-70-37 Space product assurance — Determination of the
susceptibility of metals to stress-corrosion cracking
EN 16602-70-46 ECSS-Q-ST-70-46 Space product assurance — Requirements for
manufacturing and procurement of threaded fasteners
ASTM E 139 Standard test methods for conducting creep, creep-
rupture, and stress-rupture tests of metallic materials
ASTM E 399 Standard test method for plane-strain fracture
toughness of metallic materials
ASTM E 466 Standard practice for conducing force controlled
constant amplitude axial fatigue tests of metallic
materials
ASTM E 561 Standard practice for R-curve determination
ASTM E 606 Standard practice for strain-controlled fatigue testing
ASTM E 647 Standard test method for measurement of fatigue
crack growth rates
ASTM E 739 Standard practice for statistical analysis of linear or
linarized stress-life (S-N) and strain-life (e-N) fatigue
data
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ASTM E 1290 Standard test method for crack-tip opening displace-
ment (CTOD) fracture toughness measurement
ASTM E 1820 Standard test method for measurement of fracture
toughness
EN 10002-1 Metallic materials — Tensile testing — Part 1: Method
of test at ambient temperature
EN 10002-2 Metallic materials — Tensile testing — Part 2:
Verification of the force measuring system of the
tensile testing machines
EN 10002-4 Metallic materials — Tensile testing — Part 4:
Verification of the extensometers used in uniaxial
testing
ESDU 96013:1996 Fracture toughness (KIc) values of some aluminium
alloys
ISO 7539-6:2003 Corrosion of metals and alloys — Stress corrosion
testing — Part 6: Preparation and use of pre-cracked
specimens for tests under constant load or constant
displacement
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3
Terms, definitions and abbreviated terms
3.1 Terms defined in other standards
For the purpose of this Standard, the terms and definitions from
ECSS-S-ST-00-01 and ECSS-Q-ST-70 apply.
3.2 Terms specific to the present standard
3.2.1 crack tip plastic zone
plastically deformed region in a material adjacent to a crack tip
3.2.2 creep
time-dependent increase in strain in a material resulting from force
3.2.3 damage tolerance
in a material or structure, the capability to withstand stresses or loads in the
presence of defects
3.2.4 failure
condition generally caused by break or collapse so that a structural element can
no longer fulfil its purpose
3.2.5 fatigue
in a material, the failure phenomenon which results from repeated fluctuation
of stress
3.2.6 fracture toughness
inherent resistance of a material in the presence of a crack-like defect
3.2.7 finite life range
life range, in which all test pieces before a predetermined number of cycles fail
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3.2.8 mechanical properties
those properties of a material that are associated with elastic and inelastic
reaction when force is applied, or that involve the relationship between stress
and strain
3.2.9 mechanical testing
determination of mechanical properties
3.2.10 raw material
material from which specimens are manufactured
3.2.11 specimen
representative fraction of material tested or analysed in order to determine
mechanical properties
3.2.12 transition range
-6 -7
predetermined number of cycles of stress cycles (typically 5 x 10 to 5 x 10
cycles), where failure as well as non-failure occur.
3.2.13 threaded fastener
device composed by a cylindrical screwed bar provided with a head and a
metal collar, screwed internally, to fit the cylindrical bar that is to hold parts
firmly together in an assembly
3.2.14 weld heat affected zone (HAZ)
portion of material in a welded joint whose microstructure and physical
properties are affected by the heat input during welding
3.3 Abbreviated terms
For the purpose of this Standard, the abbreviated terms from ECSS-S-ST-00-01
and the following apply:
Abbreviation Meaning
American Society for Testing and Materials
ASTM
European Committee for Standardization
CEN
crack tip opening displacement
CTOD
engineering sciences data unit
ESDU
heat affected zone
HAZ
International Organization for Standardization
ISO
nonconformance report
NCR
non-destructive inspection
NDI
raw material certificate
RMC
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3.4 Symbols
Symbol Meaning
compact tension specimen
C(T)
J-integral
J
J-integral plane-strain fracture toughness
JIc
stress intensity factor
K
stress intensity plane-strain fracture toughness
KIc
maximum stress intensity factor
Kmax
opening mode of loading
Mode I
stress ratio
R
specimen stress ratio
Rsx
middle tension specimen
M(T)
crack growth rate
da/dn
stress intensity factor range
ΔK
fatigue crack propagation threshold
ΔKth
threshold stress intensity factor for susceptibility
KISCC
to stress corrosion cracking
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4
Principles
4.1 Overview
This Standard specifies requirements to conduct tests in order to characterize
mechanical behaviour and properties of metallic materials. Selection criteria of
mechanical tests are based on the significance and use of each specified test
method. Test methods, which are covered in this Standard, are characterized in
the following paragraphs.
4.2 Tensile test
Tensile tests provide information on the strength and ductility of materials
under uniaxial tensile stresses. Test results can be used in comparing materials,
alloy development, design and quality control. The test method covers the
tension testing of metallic materials in any form at room temperature, and
specifically the methods determine yield strength, yield point elongation,
tensile strength, elongation and reduction of area.
4.3 Fracture toughness test
4.3.1 Overview
This test refers to methods to determine fracture toughness of metallic materials
using the following parameters: stress intensity factor (K), J-integral (J), R-curve
and crack tip opening displacement (CTOD). The fracture toughness
determined in accordance with this method is for opening mode (Mode I) of
loading.
4.3.2 Determination of fracture toughness using
the K test method
Ic
This method provides the measurement of crack-extension resistance at the
start of a crack extension for slow rates of loading and when the crack-tip
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plastic zone is small compared to both the crack size and to the specimen
dimension in the direction of the constraint.
The method covers the determination of linear elastic plane-strain fracture
toughness (KIc) of metallic materials by tests using a variety of fatigue-
precracked specimens.
4.3.3 Determination of fracture toughness using
the J test method
Ic
This method provides the measurement of crack-extension resistance near the
onset of stable crack extension for slow rates of loading and substantial plastic
deformation.
The method covers the determination of the J-integral plane-strain fracture
toughness (JIc) of metallic materials.
4.3.4 Characterization of fracture toughness
using the R-curve test method
This method provides a characterization of the resistance to fracture of metallic
materials during incremental slow stable crack extension and result from
growth of the plastic zone as the crack extends from a sharp notch. Materials
that can be tested for R-curve development are not limited by strength,
thickness, or toughness provided that specimens are of sufficient size to remain
predominantly elastic.
The method covers the determination of resistance to fracturing of metallic
materials by R-curves obtained by testing compact tension specimens C(T) or
middle tension specimens M(T).
4.3.5 Characterization of fracture toughness
using the CTOD test method
This test method provides a characterization of the fracture toughness of
metallic materials and is used for materials that exhibit a change from ductile to
brittle behaviour with decreasing temperature. This method is also used to
characterize the toughness of materials for which the properties and thickness
of interest preclude the determination of KIc fracture toughness in accordance
with ASTM E 399.
The specimen dimensions can affect the values of CTOD. For this reason
specimens of same dimensions are used when comparing test results.
The method covers the determination of critical crack tip opening displacement
(CTOD) values at one or more of several crack extension events. These CTOD is
used as measures of fracture toughness for metallic materials.
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4.4 Fatigue test
4.4.1 General
Fatigue test refers to tests methods for the determination of fatigue strength of
metallic materials subjected to constant amplitude cycling loading.
4.4.2 Force controlled constant amplitude axial
fatigue test
The force controlled axial fatigue test is used to determine the effect of
variations in stress, material, geometry and surface condition on the fatigue
resistance of materials subjected to fatigue loading. The results can also be used
as a guideline for the selection of metallic materials for service under conditions
of repeated direct stress.
The method covers axial force controlled fatigue tests to obtain the fatigue
strength of materials in the fatigue regime, where the strains are predominately
elastic throughout the test.
4.4.3 Strain-controlled fatigue test
Strain-controlled fatigue is important for situations in which components or
portions of components undergo either mechanically or thermally induced
cyclic plastic strains that cause failure within relatively few cycles (i.e. fatigue
5
life < 10 cycles).
The method covers axial strain-controlled fatigue tests to obtain the fatigue
strength of materials in the fatigue regime where the strains are predominately
plastic.
4.5 Fatigue crack propagation test
4.5.1 Stable crack growth rate
Fatigue crack growth rate (da/dn) expressed as a function of crack tip stress
intensity factor range ( ∆K), characterizes a material’s resistance to stable crack
propagation under cyclic loading. Results from this test together with data on
toughness are used in the prediction of the damage tolerance behaviour
(typically the cycles or service period to grow a crack to a certain crack size, the
maximum permissible crack size and residual strength) and fatigue life
prediction for structural components.
The method covers the determination of stable crack growth rates from near-
threshold propagation regime to controlled crack propagation instability.
Results are expressed in terms of da/dn versus ∆K.
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4.5.2 Crack propagation threshold
Although the fatigue-crack propagation threshold ( ∆Kth) is defined as the
asymptotic value of ∆K at which da/dn approaches zero, an operational, though
arbitrary, definition of ∆Kth is given for most materials. This value is defined as
∆K, which corresponds to a specified fatigue crack growth rate (typically for
-8
crack growth rates of 10 m/cycle or less).
It is found that the propagation threshold behaviour of long cracks can be
described in terms of stress ratio (R) as well as in terms of maximum stress
intensity Kmax, (see references [1], [2] and [3] in Annex D). From a practical point
of view, testing at constant Kmax allows to proceed faster compared to testing at
constant R, since load history effects are generally negligible. The approach is
based on the observation that for many alloys ∆Kth vs. Kmax relationships show a
quasi-linear dependency above certain Kmax values. Similarly, Kmax vs. R
relationships at low R values can be approximated by linear relations.
Under the assumption of linear dependence, ∆Kth vs. Kmax or Kmax vs. R,
relations for a material can be determined by a relatively low number of tests.
Accordingly the requirement section covers two methods to determine the
fatigue crack propagation threshold for metallic materials:
Determination of an operational value of ∆Kth) according to ASTM E 647.
Determination of ( ∆Kth) by testing at constant Kmax.
4.6 Fracture and fatigue test in special environment
Fatigue and crack propagation behaviour of metallic materials exposed to
gaseous or liquid environments can differ from that exhibited in air. Test results
obtained from fatigue and fracture tests in environments representative of the
service conditions are used to evaluate the influence of specific environments
on the material behaviour.
The method covers tests to determine the influence of environments
representative of service conditions on the fatigue and fracture behaviour of
metallic materials.
4.7 Stress corrosion cracking test
4.7.1 Overview
The test refers to methods for the determination of the susceptibility of metallic
materials to stress corrosion cracking.
4.7.2 Stress corrosion cracking test using smooth
specimens
The results of this tests are used to classify alloys, weldments and their
individual heat treatment conditions with respect to the material resistance
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against stress corrosion cracking. When sufficient stress corrosion data exists
the alloy designation can be submitted for inclusion into relevant tables
contained in ECSS-Q-ST-70-36.
The method covers the determination of the susceptibility of metals and
weldments to stress corrosion cracking by alternate immersion in 3,5 % sodium
chloride water solution under constant load.
4.7.3 Stress corrosion cracking test using pre-
cracked specimens
This test method allows the determination of the threshold stress intensity
factor value for stress corrosion cracking KISCC, and the kinetics of crack
propagation.
The use of pre-cracked specimens acknowledges the fact that defects introduced
during manufacturing and subsequent services are always present in real
structures. Furthermore, the presence of such defects can cause a susceptibility
to stress corrosion cracking, which in some materials (e.g. titanium alloys) is not
always evident from tests conducted on smooth specimens.
This test method covers preparing and testing of pre-cracked specimens for
investigating susceptibility to stress corrosion cracking of metallic materials.
4.8 Creep test
The results of this test method are used to assess the load-carrying ability of a
material at high temperatures for limited deformations and as a function of
time. The test provides information to assess the suitability of materials for high
temperature structural applications.
The method covers the determination of the amount of deformation as a
function of time (creep test) and of the time for fracture to occur (rupture test) in
materials subjected to constant tensile forces at constant temperature.
4.9 Test results presentation
Before results obtained from mechanical tests can be applied with confidence,
allowable values are statistically determined. The applicability of statistical
methods to the evaluation of numerical results depends on:
• the number of tests performed on a specific material and test conditions,
which should be large enough to constitute a statistically significant
sample;
• the assumption that test data constitute a random sample of (or
representation of) the population of the material under investigation.
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5
Requirements
5.1 Customer agreement
a. Test meth
...
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