ASTM E139-11(2018)
(Test Method)Standard Test Methods for Conducting Creep, Creep-Rupture, and Stress-Rupture Tests of Metallic Materials
Standard Test Methods for Conducting Creep, Creep-Rupture, and Stress-Rupture Tests of Metallic Materials
SIGNIFICANCE AND USE
4.1 Rupture tests, properly interpreted, provide a measure of the ultimate load-carrying ability of a material as a function of time. Creep tests measure the load-carrying ability for limited deformations. The two tests complement each other in defining the load-carrying ability of a material. In selecting material and designing parts for service at elevated temperatures, the type of test data used will depend on the criterion of load-carrying ability that better defines the service usefulness of the material.
SCOPE
1.1 These test methods cover the determination of the amount of deformation as a function of time (creep test) and the measurement of the time for fracture to occur when sufficient force is present (rupture test) for materials when under constant tensile forces at constant temperature. It also includes the essential requirements for testing equipment. For information of assistance in determining the desirable number and duration of tests, reference should be made to the product specification.
1.2 These test methods list the information which should be included in reports of tests. The intention is to ensure that all useful and readily available information is transmitted to interested parties. Reports receive special attention for the following reasons: (1) results from different, recognized procedures vary significantly; therefore, identification of methods used is important; (2) later studies to establish important variables are often hampered by the lack of detailed information in published reports; (3) the nature of prolonged tests often makes retest impractical, and at the same time makes it difficult to remain within the recommended variations of some controlled variables. A detailed report permits transmittal of test results without implying a degree of control which was not achieved.
1.3 Tests on notched specimens are not included. These tests are addressed in Practice E292.
1.4 Tests under conditions of short times are not included. These test methods are addressed in Test Methods E21.
1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E139 − 11 (Reapproved 2018)
Standard Test Methods for
Conducting Creep, Creep-Rupture, and Stress-Rupture
Tests of Metallic Materials
This standard is issued under the fixed designation E139; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.1 These test methods cover the determination of the
mine the applicability of regulatory limitations prior to use.
amount of deformation as a function of time (creep test) and
1.7 This international standard was developed in accor-
the measurement of the time for fracture to occur when
dance with internationally recognized principles on standard-
sufficient force is present (rupture test) for materials when
ization established in the Decision on Principles for the
under constant tensile forces at constant temperature. It also
Development of International Standards, Guides and Recom-
includes the essential requirements for testing equipment. For
mendations issued by the World Trade Organization Technical
information of assistance in determining the desirable number
Barriers to Trade (TBT) Committee.
and duration of tests, reference should be made to the product
specification.
2. Referenced Documents
1.2 These test methods list the information which should be
included in reports of tests. The intention is to ensure that all
2.1 ASTM Standards:
useful and readily available information is transmitted to
E4Practices for Force Verification of Testing Machines
interested parties. Reports receive special attention for the
E6Terminology Relating to Methods of MechanicalTesting
following reasons: (1) results from different, recognized pro-
E8/E8MTest Methods for Tension Testing of Metallic Ma-
cedures vary significantly; therefore, identification of methods
terials
used is important; (2) later studies to establish important
E21TestMethodsforElevatedTemperatureTensionTestsof
variables are often hampered by the lack of detailed informa-
Metallic Materials
tioninpublishedreports;(3)thenatureofprolongedtestsoften
E29Practice for Using Significant Digits in Test Data to
makesretestimpractical,andatthesametimemakesitdifficult
Determine Conformance with Specifications
to remain within the recommended variations of some con-
E74Practices for Calibration and Verification for Force-
trolled variables. A detailed report permits transmittal of test
Measuring Instruments
results without implying a degree of control which was not
E83Practice for Verification and Classification of Exten-
achieved.
someter Systems
E177Practice for Use of the Terms Precision and Bias in
1.3 Testsonnotchedspecimensarenotincluded.Thesetests
ASTM Test Methods
are addressed in Practice E292.
E220Test Method for Calibration of Thermocouples By
1.4 Tests under conditions of short times are not included.
Comparison Techniques
These test methods are addressed in Test Methods E21.
E292Test Methods for ConductingTime-for-Rupture Notch
1.5 Thevaluesstatedininch-poundunitsaretoberegarded
Tension Tests of Materials
as standard. The values given in parentheses are mathematical
E633Guide for Use of Thermocouples in Creep and Stress-
conversions to SI units that are provided for information only
Rupture Testing to 1800°F (1000°C) in Air
and are not considered standard.
E1012Practice for Verification of Testing Frame and Speci-
men Alignment Under Tensile and Compressive Axial
1.6 This standard does not purport to address all of the
Force Application
safety concerns, if any, associated with its use. It is the
These test methods are under the jurisdiction of theASTM Committee E28 on
Mechanical Testing For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2018. Published November 2018. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1958. Last previous edition approved in 2011 as E139–11. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0139-11R18. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E139 − 11 (2018)
3. Terminology 4. Significance and Use
4.1 Rupturetests,properlyinterpreted,provideameasureof
3.1 Definitions—The definitions of terms relating to creep
the ultimate load-carrying ability of a material as a function of
testing, which appear in Section E of Terminology E6 shall
time. Creep tests measure the load-carrying ability for limited
apply to the terms used in this practice. For the purpose of this
deformations.Thetwotestscomplementeachotherindefining
practiceonly,someofthemoregeneraltermsareusedwiththe
theload-carryingabilityofamaterial.Inselectingmaterialand
restricted meanings given below.
designingpartsforserviceatelevatedtemperatures,thetypeof
3.2 Definitions of Terms Specific to This Standard:
test data used will depend on the criterion of load-carrying
3.2.1 axial strain—the average of the strain measured on
abilitythatbetterdefinestheserviceusefulnessofthematerial.
opposite sides and equally distant from the specimen axis.
5. Apparatus
3.2.2 bending strain—the difference between the strain at
the surface of the specimen and the axial strain. In general it
5.1 Testing Machine: The accuracy of the testing machine
variesfrompointtopointaroundandalongthereducedsection
shall be within the permissible variation specified in Practices
of the specimen.
E4.
3.2.2.1 maximum bending strain—measured at a position
5.1.1 Exercise precaution to ensure that the force on the
along the length of the reduced section of a straight unnotched
specimens is applied as axially as possible. Perfect axial
specimen.
alignment is difficult to obtain, especially when the pull rods
3.2.3 creep—the time-dependent strain that occurs after the and extensometer rods pass through packing at the ends of the
application of a force which is thereafter maintained constant.
furnace. However, the machine and grips should be capable of
applying force to a precisely made specimen so that the
3.2.4 creep-rupture test—a test in which progressive speci-
maximum bending strain does not exceed 10% of the axial
men deformation and the time for rupture are measured. In
strain,whenthecalculationsarebasedonstrainreadingstaken
general,deformationismuchlargerthanthatdevelopedduring
at the lowest force for which the machine is being qualified.
a creep test.
NOTE 1—This requirement is intended to limit the maximum contribu-
3.2.5 creep test—a test that has the objective of measuring
tion of the testing apparatus to the bending which occurs during a test. It
creep and creep rates occurring at stresses usually well below
is recognized that even with qualified apparatus, different tests may have
those which would result in fracture during the time of testing.
quite different percent bending strains due to chance orientation of a
Since the maximum deformation is only a few percent, a
loosely fitted specimen, lack of symmetry of that particular specimen,
sensitive extensometer is required. lateral force from furnace packing, and thermocouple wire, etc.
5.1.1.1 In testing of low ductility material, even a bending
3.2.6 gage length—the original distance between gage
strain of 10% may result in lower strength than would be
marks made on the specimen for determining elongation after
obtained with improved axiality. In these cases, measurements
fracture.
of bending strain on the specimen to be tested may be
3.2.7 length of the reduced section—the distance between
specificallyrequestedandthepermissiblemagnitudelimitedto
tangent points of the fillets which bound the reduced section.
a smaller value.
3.2.7.1 The adjusted length of the reduced section is greater
5.1.1.2 The testing apparatus may be qualified by measure-
than the length of the reduced section by an amount calculated
ments of axiality made at room temperature. When one is
to compensate for strain in the fillet region (see 8.2.3).
making an evaluation of equipment, the specimen form should
3.2.8 plastic strain during force application—the portion of
be the same as that used during the elevated-temperature tests.
the strain during force application determined as the offset
Theevaluationspecimenconcentricityshallbeatleastasgood
from the linear portion to the end of a stress-strain curve made
as called out in the specimen drawing. Only elastic strains
during force application. The offset construction is shown in
should occur throughout the reduced section.This requirement
Test Methods E8/E8M.
may necessitate use of a material different from that used
during the elevated-temperature test.
3.2.9 reduced section, of the specimen—the central portion
5.1.1.3 Test Method E1012, or an equivalent test method
ofthelengthhavingacrosssectionsmallerthantheendswhich
(1), shall be used for the measurement and calculation of
are gripped. The cross section is uniform within tolerances
bending strain for round, rectangular, and thin strip specimens.
prescribed in 6.6.
5.1.1.4 Axiality measurements should be made at room
3.2.10 strain during force application—the change in strain
temperature during the initial setup of the assembled test
during the time interval from the start of force to the instant of
machine, (including the pull rods, and grips) before use for
full-force application.
testing. Gripping devices and pull rods may oxidize, warp, and
3.2.11 stress-rupturetest—atestinwhichtimeforruptureis
creep with repeated use at elevated temperatures. Increased
measured, no deformation measurements being made during
bending stresses may result. Therefore, grips and pull rods
the test.
should be periodically retested for axiality and reworked when
necessary.
3.2.12 total plastic strain, at a specified time—equal to the
sum of plastic strain during force application plus creep.
3.2.13 total strain, at a specified time—equal to the sum of
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
the strain during force application plus creep. this standard.
E139 − 11 (2018)
nationordeteriorationwithuse,lead-wireerror,errorarisingfrommethod
5.1.2 Thetestingmachineshallincorporatemeansoftaking
of attachment to the specimen, direct radiation of heat to the bead,
up the extension of the specimen so that the applied force will
heat-conduction along thermocouple wires, etc.
be maintained within the limits specified in 5.1. The extension
5.3.3 Temperature measurements shall be made with cali-
of the specimen shall not allow the force application system to
bratedthermocouples.Representativethermocouplesshouldbe
introduce eccentricity of force application in excess of the
calibrated from each lot of wires used for making base-metal
limits specified in 5.1.1. The take-up mechanism shall avoid
thermocouples. Except for relatively low temperatures of
introducing shock forces, overloading due to friction or inertia
exposure, base-metal thermocouples are subject to error upon
in the force application system, or apply torque to the speci-
reuse unless the depth of immersion and temperature gradients
men.
of the initial exposure are reproduced. Consequently base-
5.1.3 The testing machine shall be erected to secure reason-
metal thermocouples should be calibrated by the use of
able freedom from vibration and shock due to external causes.
representativethermocouplesandactualthermocouplesusedto
Precautions shall be made to minimize the transmission of
measure specimen temperatures shall not be calibrated. Base-
shock to neighboring test machines and specimens when a
metal thermocouples also should not be re-used without
specimenfractures.Vibrationandshockeffectsmaybeseenas
clipping back to remove wire exposed to the hot zone . Any
noise in the curve when plotting the creep versus time. When
reuse of base-metal thermocouples after relatively low-
such effects are visible in the plotted data, vibration and shock
temperature use without this precaution should be accompa-
should not introduce apparent noise to the creep data in excess
nied by recalibration data demonstrating that calibration was
of 7.5% total creep or total plastic strain. Such external
not unduly affected by the conditions of exposure.
vibrations shall not result in applied force errors in excess of
+1% of the specified test force. 5.3.3.1 Noble-metalthermocouplesarealsosubjecttoerrors
duetocontamination,etc.,andshouldbeannealedperiodically
5.1.4 For high-temperature testing of materials which are
and checked for calibration. Care should be exercised to keep
readily attacked by their environment (such as oxidation of
the thermocouples clean prior to exposure and during use at
metalinair),thespecimenmaybeenclosedinacapsulesothat
elevated temperatures.
it can be tested in a vacuum or inert-gas atmosphere. When
suchequipmentisused,thenecessarycorrectionstoobtaintrue 5.3.3.2 Measurement of the drift in calibration of thermo-
specimen applied forces shall be made. For instance, compen- couples during use is difficult. When drift is a problem during
tests, a method should be devised to check the readings of the
sation shall be made for differences in pressures inside and
outside of the capsule and for any force application variation thermocouples on the specimens during the test. For reliable
calibration of thermocouples after use, the temperature gradi-
due to sealing-ring friction, bellows or other features.
ent of the testing furnace must be reproduced during the
5.2 Heating Apparatus: The apparatus for and method of
recalibration.
heating the specimens shall provide the temperature control
5.3.4 Temperature-measuring, controlling and recording in-
necessary to satisfy the requirements specified in 8.4.4 without
strumentsshouldbecalibratedperiodicallyagainstasecondary
manual adjustments more frequent than once in each 24-h
standard, such as a precision potentiometer. Lead-wire error
periodafterforceapplication.Automatictemperaturecontrolis
shouldbecheckedwiththeleadwiresinplaceastheynormally
preferred.
are used.
5.2.1 Heating shall be by an electric resistance or radiation
furnacewiththespecimeninairatatmosph
...
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