ASTM E1290-08e1

Standard Test Method for Crack-Tip Opening Displacement (CTOD) Fracture Toughness Measurement (Withdrawn 2013)

SIGNIFICANCE AND USE
This test method characterizes the fracture toughness of materials through the determination of crack-tip opening displacement (CTOD) at one of three events: (a) onset of unstable crack extension without significant prior stable crack extension, or (b) onset of unstable crack extension with significant prior stable crack extension, or (c) the end-of-test after significant slow stable crack extension. This test method may also be used to characterize the toughness of materials for which the properties and thickness of interest preclude the determination of K lc fracture toughness in accordance with Test Method E399.
The different values of CTOD determined by this test method can be used to characterize the resistance of a material to crack initiation and early crack extension at a given temperature.
The values of CTOD may be affected by specimen dimensions. It has been shown that values of CTOD determined on SE(B) specimens using the square section geometry may not be the same as those using the rectangular section geometry, and may differ from those obtained with either the C(T) or A(B) specimens.
The values of CTOD determined by this test method may serve the following purposes:
In research and development, CTOD testing can show the effects of certain parameters on the fracture toughness of metallic materials significant to service performance. These parameters include material composition, thermo-mechanical processing, welding, and thermal stress relief.
CTOD testing may be used in specifications of acceptance and manufacturing quality control of base materials, weld metals, and weld heat affected zones. Previous versions of Test Method E1290 made effective use of the value of CTOD at the first attainment of a maximum force plateau for such purposes. Qualitative comparisons of this type can only be made if a consistent specimen geometry is used and the materials compared have similar constitutive properties. The value of CTOD at the first attainment of a...
SCOPE
1.1 This test method covers the determination of critical crack-tip opening displacement (CTOD) values at one or more of several crack extension events, and may be used to measure cleavage crack initiation toughness for materials that exhibit a change from ductile to brittle behavior with decreasing temperature, such as ferritic steels. This test method applies specifically to notched specimens sharpened by fatigue cracking. The recommended specimens are three-point bend [SE(B)], compact [C(T)], or arc-shaped bend [A(B)] specimens. The loading rate is slow and influences of environment (other than temperature) are not covered. The specimens are tested under crosshead or clip gage displacement controlled loading.
1.1.1 The recommended specimen thickness, B, for the SE(B) and C(T) specimens is that of the material in thicknesses intended for an application. For the A(B) specimen, the recommended depth, W, is the wall thickness of the tube or pipe from which the specimen is obtained. Superficial surface machining may be used when desired.
1.1.2 For the recommended three-point bend specimens [SE(B)], width, W, is either equal to, or twice, the specimen thickness, B, depending upon the application of the test. (See 4.3 for applications of the recommended specimens.) For SE(B) specimens the recommended initial normalized crack size is 0.45 ≤ ao/W  ≤ 0.70. The span-to-width ratio (S/W) is specified as 4.
1.1.3 For the recommended compact specimen [C(T)] the initial normalized crack size is 0.45 ≤ ao/W ≤ 0.70. The half-height-to-width ratio (H/W) equals 0.6 and the width to thickness ratio W/B is specified to be 2.
1.1.4 For the recommended arc-shaped bend [A(B)] specimen, B is one-half the specimen depth, W. The initial normalized crack size is 0.45  ao/W 0.70. The span to width ratio, S/W, may be either 3 or 4 depending on the ratio of the inner to outer tube radius. For an inner radius, r1, to an outer radius, r2, rat...

General Information

• Status: Withdrawn
• Publication Date: 31-Mar-2008
• Withdrawal Date: 31-Dec-2012
• ICS: 77.040.10 - Mechanical testing of metals
• Technical Committee: E08 - Fatigue and Fracture
• Drafting Committee: E08.07 - Fracture Mechanics

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
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Designation: E1290 − 08
StandardTest Method for
Crack-Tip Opening Displacement (CTOD) Fracture
1
Toughness Measurement
This standard is issued under the fixed designation E1290; 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.
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´ NOTE—Figure 1 was editorially revised in March 2010.
1. Scope ratio, S/W, may be either 3 or 4 depending on the ratio of the
inner to outer tube radius. For an inner radius, r , to an outer
1
1.1 This test method covers the determination of critical
radius, r , ratio of > 0.6 to 1.0, a span to width ratio, S/W,of
2
crack-tip opening displacement (CTOD) values at one or more
4maybeused.Forr /r ratiosfrom0.4to0.6,anS/Wof3may
1 2
of several crack extension events, and may be used to measure
be used.
cleavage crack initiation toughness for materials that exhibit a
change from ductile to brittle behavior with decreasing 1.2 The values stated in SI units are to be regarded as the
temperature, such as ferritic steels. This test method applies standard. The values given in parentheses are for information
specifically to notched specimens sharpened by fatigue crack- only.
ing. The recommended specimens are three-point bend
1.3 This standard does not purport to address all of the
[SE(B)], compact [C(T)], or arc-shaped bend [A(B)] speci-
safety concerns, if any, associated with its use. It is the
mens. The loading rate is slow and influences of environment
responsibility of the user of this standard to establish appro-
(other than temperature) are not covered. The specimens are
priate safety and health practices and determine the applica-
tested under crosshead or clip gage displacement controlled
bility of regulatory limitations prior to use.
loading.
1.1.1 The recommended specimen thickness, B, for the
2. Referenced Documents
SE(B)andC(T)specimensisthatofthematerialinthicknesses
2
2.1 ASTM Standards:
intended for an application. For the A(B) specimen, the
E4Practices for Force Verification of Testing Machines
recommended depth, W, is the wall thickness of the tube or
E8/E8MTest Methods for Tension Testing of Metallic Ma-
pipe from which the specimen is obtained. Superficial surface
terials
machining may be used when desired.
E399Test Method for Linear-Elastic Plane-Strain Fracture
1.1.2 For the recommended three-point bend specimens
Toughness K of Metallic Materials
Ic
[SE(B)], width, W, is either equal to, or twice, the specimen
E1820Test Method for Measurement of FractureToughness
thickness, B, depending upon the application of the test. (See
E1823TerminologyRelatingtoFatigueandFractureTesting
4.3 for applications of the recommended specimens.) For
E1921 Test Method for Determination of Reference
SE(B) specimens the recommended initial normalized crack
Temperature, T , for Ferritic Steels in the Transition
o
size is 0.45 ≤ a /W ≤ 0.70. The span-to-width ratio (S/W)is
o
Range
specified as 4.
1.1.3 For the recommended compact specimen [C(T)] the
3. Terminology
initial normalized crack size is 0.45 ≤ a /W ≤ 0.70. The
o
3.1 Terminology E1823 is applicable to this test method.
half-height-to-width ratio (H/W) equals 0.6 and the width to
thickness ratio W/B is specified to be 2.
3.2 Definitions:
1.1.4 For the recommended arc-shaped bend [A(B)]
3.2.1 crack-tip opening displacement, (CTOD), δ[L]—the
specimen, B is one-half the specimen depth, W. The initial
crackdisplacementresultingfromthetotaldeformation(elastic
normalized crack size is 0.45 < a /W< 0.70. The span to width
o
plus plastic) at variously defined locations near the original
(prior to an application of force) crack tip.
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This test method is under the jurisdiction ofASTM Committee E08 on Fatigue
and Fracture and is the direct responsibility of Subcommittee E08.07 on Fracture
2
Mechanics. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2008. Published July 2008. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
ϵ1
published in 1989. Last previous edition published in 2007 as E1290–07 . DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E1290-08E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E1290 − 08
3.2.1.1 Discussion—In common practice, δ is estimated for influences of the testing conditions, such as loading rate and
Mode I by inference from observations of crack displacement temperature, should be considered.
nearby or away, or both for the crack
...