ASTM E992-84(1989)E01

Practice for Determination of Fracture Toughness of Steels Using Equivalent Energy Methodology (Withdrawn 1997)

SCOPE
1.1 This practice covers the determination of the fracture toughness ( K-EE ) of a steel by testing fatigue-cracked bend or compact specimens and interpreting the load displacement curves according to equivalent energy methodology.  
1.2 The practice is limited to the analyses of test results from the standard bend and compact specimens of Test Method E399, with exception noted in 7.2 (see Figs. 1 and 2). Size may be a variable.
1.3 Values stated in inch-pound units are to be regarded as the standard. SI units are provided for information only.  
1.4 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use .

General Information

• Status: Withdrawn
• Publication Date: 31-Dec-1988
• Withdrawal Date: 09-Jul-1997
• Technical Committee: E08 - Fatigue and Fracture

Standards Content (Sample)

ASTM E992 8L( - 0757510 004730i 8 -
-a&-%-
Designation: E 992 - 84 (Reapproved 1989)"
AMERICAN SOCIETY FOR TESTING AND MATERIALS
1916 Race St., Philadelphia, Pa. 19103
Reprinted from the Annual Book of ASTM Standards, Copyright ASTM
, If not listed in the current combined index, will appear in the next edition.
Standard Practice for .
Determination of a Fracture Toughness of Steels Using
Equivalent Energy Mekkodology'
This standard is issued under the fixed designation E 992; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (c) indicates an editorial change since the last revision or reapproval.
NOTE-Editorial changes were made throulout in March 1989.
E 813 Test Method for JI, a Measure of Fracture
1. Scope
Toughness3
1.1 This practice covers the determination of the fracture
toughness (K-EE) of a steel by testing fatigue-cracked bend
3. Terminology
or compact specimens and interpreting the load displace-
ment curves according to equivalent energy methodology. 3.1 Terminology E 616 is applicable to this practice.
1.2 The practice is limited to the analyses of test results 3.2 Definirion: .
from the standard bend and compact specimens of Test 3.2.1 fracture toughness-a generic term for measures of
resistance to extension of a crack.
Method E 399, with exception noted in 7.2 (see Figs. 1 and
2). Size may be a variable. 3.3 Description of Term Specific to This Standard:
3.3.1 equivalent energy fracture toughness, K- EE
1.3 Values stated in inch-pound units are to be regarded
SI units are provided for information only. (FL-3/2)-the crack extension resistance determined by the
as. the standard.
1.4 This standard may involve hazardous materials, oper- procedure specified in this practice.
ations, and equipment. This standard does not purport to Discussion-The thickness, (B), of the standard specimen
address all of (he safety problems associated wirh its use. It is from which the result is obtained should be identified in
(lie responsibiiily of the user of (his standard to esrablish quoting the result. For specimens thicker than the standard
appropriate safety and health practices and determine the specimens (see 7.2), both B and W should be specified. See
applicability of regulatory limitations prior to use. specimen designation code in Terminology E 616.
4, Summary of Practice
2. Referenced Documents
4.1 This practice involves tension or three-point bend
2.1 ASTM Standards:
testing of notched specimens that have been precracked in
A 5331A 533M Specification for Pressure Vessel Plates,
fatigue in accordance with Test Method E 399. Load versus
Alloy Steel, Quenched and Tempered, Manganese-Mo-
displacement is measured autographically to maximum load
lybdenum and Manganese-Molybdenum-Nickel*
by means of a displacement gage which spans the notch. The
E 4 Practices for Load Verification of Testing Machines3
calculated value, designated K-EE, is determined from the
E 6 Terminology Relating to Methods of Mechanical
load-displacement 'curve using the area to maximum load
Testing3
with exceptions noted in Section 9. Nonlinearity in the
E 8 Test Methods of Tension Testing of Metallic Mate-
load-displacement curve to maximum load may occur indi-
na1s3
cating significant amounts of plasticity or stable' ductile
E 83 Practice for Verification and Classification of Ex-
tearing, or both. However, there is no guarantee that crack
tensometer~~
initiation has occurred at maximum load.
E 337 Test Method for Measuring Humidity with a Psy-
4.2 Background application information concerning the
chrometer (The Measurement of Wet- and Dry-Bulb
basis for the development of this practice is given in Refs (1)
tempe rature^)^
through (10):
E 338 Method of Sharp-Notch Tension Testing of High-
Strength Sheet Materials3
5. Significance and Use
E 399 Test Method for Plane-Strain Fracture Toughness
of Metallic Materials3 5.1 This practice provides reduction of data from tests run
in accordance with Test Method E 399 that fail to meet the
E 561 Practice for R-Curve Determination3
validity criteria of that standard; but will, nonetheless,
E 6 16 Terminology Relating to Fracture Testing3
produce a fracture toughness measurement, K-EE. If the
data satis@ the validity criteria of Test Method E 399, they
This practice is under the jurisdiction of ASTM Committee E-24 on Fracture
can and should be used to calculate values of K,c.
Testing and is the direct responsibility of Subcommittee E24.03 on Alternative
5.2 The K-EE measurement provides an economical and
Fracture Test Methods.
Current edition approved June 18, 1984. Published December 1984.
Annual Book ofASTM Standards, Vol 01.04.
' Aiinilal Book ofASTM Standards. Vol 03.01.
The boldface numbers in parentheses refer to the references af the end of this
Anniral Book ofASThí Standards, Vol 11.03.
practice.
\
I
__
ASTM E792 84 W 0757510 0049303 T W
E992
ENVELOPE OF STARTER
NOTCH PLUS CRACK
(SEE TEST METHOD E3991
1%
\%-r
LB+ .OlOW
NOTE 1-A surface shall be perpendicular and parallel as applicable withln 0.001 WTIR
NOTE 2-Crack starter notch shall be perpendicular to specimen surfaces to wlthln 12'.
FIG. 1 Bend Specimen-Standard Proportions and Tolerances
ENVELOPE OF STARTER
NOTCH PLUS CRACK
(SEE TEST METHOD E3991
\ ,--;52&05 W DIA
al
3;.
P'
+ W 2.005 W-4
d
- 1.25 w I.01OW
\
NOTE I-A surface shall be perpendicular and parailel as applicable within 0.002 WTIR.
NOTE 2-The Intersection of the crack starter notch tips with the two specimen surfaces shall be equally distant from the top and bottom edges of the specimen within
0.005 W.
FIG. 2 Compact Specimen-Standard Proportions and Tolerances
simple method of determining fracture toughness values from devices meeting requirements of Practices E 4. Use the grips
specimens that are relatively small. This practice is applicable and fixtures as described in Test Method E 399.
to assessing toughness in a limited region or to materials of 6.2 Displacement Gage-The displacement gage output
limited thickness and availability (for example: welds, heat- must indicate accurately the relative displacement of two
affected zones, and nozzle-corner materials). precisely located gage positions spanning the crack notch. In
53 The a/W restriction as defined in Test Method E 399 testing small specimens the gage recommended in Test
is relaxed and is more in keeping with Practice E 56 I, Tables Method E 399 may have a sufficient linear working range;
are provided in this practice for 0.45 5 a/W L 0.75. however, in testing larger specimens, displacements may be
5.4 There is no restriction on specimen size in this of such magnitude that gages with greater working ranges
practice; however, since the maximum measuring capacity is may be needed; in this case Practice E 56 1 applies. However,
size dependent, some knowledge of this dependence and the an accuracy of 1 % of the value over the working range of the
magnitude of acceptable toughness is desirable. Guidance in gage is recommended.
7.
this area based on experience is provided in Section
7. Specimen Configuration, Dimensions, and Preparation
6. Apparatus
7.1 Specimen Size-There is no specimen size limitation
6. I This practice involves testing of notched specimens in this practice. However, in the very tough regime, small
that have been precracked in fatigue. Load versus displace- specimens may produce values considerably less than K-EE
ment across the notch is recorded autographically, Testing obtained from larger specimens. For less tough materials, the
may be done in various machines having load-sensing K-EE values may be less size dependent. Guidance as to
~ ---
/------i
ASTM E772 84 0757530 0047304 I
E992
both. Stopping the test and rescaling the coordinates are
maximum anticipated results as a function of specimen size
acceptable practices but may be inconvenient for analysis.
is given in Table i which is based on estimates of related
For many materials one method for selecting the displace-
Charpy impact upper shelf energy (11).
7.2 Specimen-This practice is limited to the standard ment per inch (25 mm) of pen travel is to divide the
E399 (see thickness by 100, for example, a compact specimen having a
bend and compact specimens of Test Method
Figs. I and 2) with the exception that the relative thickness of width of 4 in. (102 mm) [B = 2.0 in. (51 mm)], select 0.02
the specimens may be greater than those specified in Test
in./in. (0.5 mm/mm) of pen travel; for width of 1 in. (25
Method E 399. A crack length, (a), nominally equal to no
mm) [B = 0.5 in. (13 mm)], select 0.005 in./in. (0.13
less than half the specimen width, (W), is recommended
mm/mm) of travel [0.010 in./in. (0.25 mm/mm) also is
(that is, a/W > 0.50, see Figs. i and 2); however, values of
adequate].
n/W up to 0.75 are acceptable. The crack starter, fatigue
8.2 Continue the test to well past maximum load when-
precracking, and instrumentation procedures of Test
ever fracture instability does not occur to ensure that the
Method E 399 apply.
maximum load can be identified.
8.3 Unloading compliance procedures are compatible
with this practice (see Practice E 561 and Test Method
8. Procedure
E 813).
8.1 Follow appropriate section of Test Method E 399. In
setting up the displacement coordinate of the autographic
plots, make sufficient allowance for measuring loads and
9. Calculation and Interpretation
displacements for extensive plasticity and ductile tearing, or
9.1 Interpretation of Test Record-The calculation equa-
tions for K-EE are the same as those in Test Method E 399
TABLE 1 Estimated Maximum of K-EE Values as a Function of
with one exception. The exception is the definition of the
Specimen Size Based on Charpy Impact Upper Shelf Energy
load used in the KQ equations of Test Method E 399. In this
Charpy Impact Upper Shelf Energy
Thickness of
practice, the load designated here by PE (instead of Pe as in
ftnlbf (J)
Standard
Test Method E 399) is defined as follows. PE is the load
' Specimen 50 (69) 100 (136) 150 (204)
obtained by extending the linear portion of the load-
B, in. (mm)
K-€E Values.A ksi (MPa -.hl
displacement curve until the area under the linear portion
E (13) 175 (1 90) 225 (250) 250 (275)
equals the area to the maximum load sustained by the
175 (190) 250 (275) 300 (330)
1 (25)
specimen without instability. Caution is recommended when
200 (220) 275 (300) 325 (360)
2 (50)
4 (100) 200 (220) 300 (330) 400 (440)
interpreting data obtained in the toughness transition region.
Guidance on obtaining PE is given in 9.2.
A Judged to be accurate within f25 ksi- &. (28 MPa- Ji).
HMAxlMuMLoAD ,! I G AL=AREAOAF
AT 5 AREA OACD
AREA OABE = AREA OA~D
PL
I
O F ED
DISPLACEMENT
DISPLACEMENT
(a I íb)
PE
a
a
$-\
II
DISPLACEMENT DISPLACEMENT
(cl ídI
FIG. 3 Sketches Illustrating the Determination of PE

ASTM E972 84 075'7530 0049305 3 =
TABLE 3 f(a/W) for Compact Specimen
9.2 Four cases for determining PE are in Fig. 3. These are
discussed as follows: f(alW) alW
a/w a/w f(alW f(W)
9.2.1 Linear Load-Displacement Ciiwe-Fig. 3( a) ap-
0.450 8.340 0.555 11 563 0.655 17.264
0.455 8.458 0.560 11.767 0.660
17.651
plies, In this case, PE = Pe. However, Test Method E 399
0.460 0.565
8.580 11.978 0.665 18.072
may be applied. By strict adherence to this practice for this
0.465 8.704 0.570 12.196 0.670 18.510
situation, K-EE = K,. Since Test Method E 399 defines KQ
0.470 8.830 0.575 12.420 0.675 18.970
0.475
8.960 0.580 12.651 0.680 19,441
as valid or invalid by size criteria, applying Test Method
0.480 9.093 0.585 12.890 0.685 19.936
E 399 provides a direct interface of this practice with that
0.485 9.230 0.590
13.136 0.690 20.451
standard. Here K-EE and KI, are reasonably compatible. If a
0.490 9.369 0.595 13.391 0.695 20.990
0.495 9.512 0.600 13.654
0.700 21.552
result valid by Test Method E 399 is obtained it should be
0.500 9.659 0.605 13.926 0.705 22,139
called If it is not valid by Test Method E 399, it should
0.505 9.810 0.61 O 14.208
0.710 22.753
be designated K-EE.
0.510 9.964 0.61 5 14.499 0.715 23.395
0.515 10.123 0.620 14.801 0.720
24.068
9,2.2 Unstable Fracture on Rising Load-Fig. 3(b) ap-
0.520 10.286 0.625 15.113 0.725 24.772
plies, Instead of actually extending the linear portion of the
0.525 10.453 0.630 15.437
0.730 25.511
load-displacement curve it is simpler to perform the fol-
0.530 10.625 0.635 15.773 0.735 26.286
0.535 10.802 0.640 16.121 0.740
27.100
lowing steps:
0.540
10.984 0.645 16.482 0.745 27.955
9.2.2.1 Select a load (PL) on the linear portion of the
0.545 11.172 0.650 16.860
0.750 28.856
curve,
0.550 11 364
9.2.2.2 Measure the area to PL; call it AL,
9.2.2.3 Measure the area to maximum load. call it AT, and
K-EE = (P,S/B W3/2)j(a/ W)
9.2.2.4 By similar triangles, PE = PL &.
9.2.3 Stability Past Maximum Load-Fig. 3( e) applies.
where:
The technique for determining P,; is the same as in 9.2.2,
j(a/ W) = 3(a/ W)'12( i .99 - (u/ W)( i - u/ W)(2, i 5
except the displacement at maximum load may not be
- 3.93~1 w + 2.7a2/ w~)I/ 2(1 + 2a/ w)(i .- a/ ~)3/2
uniquely defined. In this practice the displacement at which
the maximum load is first obtained is to be used to define the
where (see Fig. 1):
area at maximum load. This displacement is best determined
PE = load as determined in 9.2, klbf (kN),
with the aid of a magnifying glass or a straightedge.
B = specimen thickness, in. (cm),
9.2,4 Instability Prior to Maximum Load-Fig. 3(d) ap-
S = span, in. (cm),
plies. Should an instability occur prior to the maximum load
W = specimen depth (width), in. (cm), and
such as in Fig. 3(d), the area to the instability Ioad (P,) should
a = crack length, in. (cm).
be used to calculate K-EE. This pop-in behavior can depend
To facilitate calculation of K-EE, values of f(u/W) are tabu-
on the thickness of the specimen, the stiffness of the testing lated in Table 2.
machine, or inhomogeneity of the material, or a combination 9.3.2 The equations for the standard compact specimen
thereof, and is the subject of future research (see 10.1.14). are expressed as follows:
9.3 Calculation of K-EE-The equations for calculating
K-EE = (PEfBWi/2)f(af W)
K-EE are the same as those for calculating K, of Test Method
E 399 once PQ is replaced by PE where:
9.3.1 The equations for the standard bend specimen are
j(a/ W) = [(2 + a/ W)(0.886 + 4.64~1 W - 13.32~~1 W2
expressed as follows:
+ 14.72a3/ W' - 5.6~~1 W4)]/( 1 - a/ Wl3f2
where (se
...