9. Charpy Test Bar Type
9.1 Unless specified otherwise, the notched bar type speci-
mens in Figs. 1 and 2 (for pipe type products) shall be
employed. Exceptions are defined in 9.2 and 9.3.
9.2 The unnotched charpy type specimen in Fig. 3 shall be
employed for testing of all grades of austempered ductile iron.
These irons are tested after the austempering heat treatment.
9.3 The unnotched charpy type specimen may be specified
for other types of irons or irons that have been heat treated in
various ways other than austempering, by specific agreement
between producer and purchaser.
10. Apparatus
10.1 The single-blow Charpy test for ductile and malleable
iron shall be carried out in a pendulum-type impact machine
with a capacity of at least 150 J as used for the simple beam test
for steel described in Test Methods E23.
10.2 Standard machines may be modified by using a more
sensitive scale, or pendulum machines of a lower capacity may
be used where values of less than 34 J will be obtained.
11. Test Specimens
11.1 Except for pipe, the test specimen shall have the shape
and dimensions as shown in Fig. 1 for notch charpy bars and
Fig. 3 for unnotched charpy bars. Bars must have a smooth
machined or ground surface finish. The notched area of notch
type bars shall be free of any burrs or machining marks that
could be judged to adversely influence test values.
11.2 In the case of malleable or ductile irons that are to be
tested after heat treatment, such as austempered ductile irons,
final finish grinding of longitudinal faces and cutting of the
notch must be performed after completion of all heat treatment
operations.
11.3 Test specimens taken from ductile iron pipe shall be
0.500 in. wide, measured from the notched face. The thick-
ness of the notched face shall be equal to the full wall thickness
of the pipe, t, except that specimens in which the pipe wall
specimen thickness exceeds the maximum height accommo-
dated by the impact test machine shall be machined to a
thickness that can be accommodated by the machine. Speci-
mens shall be machined in accordance with Fig. 2.
12. Procedure
12.1 Test the specimen in accordance with the procedures
set forth in Test Methods E23.
12.2 Unless otherwise specified, the test shall be performed
at 21 6 5.5°C.
12.3 For testing at other than room temperature, accuracy of
results is ensured by following the procedure outlined in Test
Methods E23.
12.4 Characterization of the fracture toughness of any cast
iron should be based upon testing at least three specimens.
13. Report
13.1 For malleable or ductile irons, the results shall be
reported as J at °C, “standard notched Charpy test”
or “standard unnotched Charpy test,” depending upon which
specimen type was employed.
NOTE—Permissible variations shall be as follows:
Adjacent sides shall be at 90° 6 10 min
Cross section dimensions 60.03 mm
Length of specimen +0, −2.5 mm
Angle of notch 61°
Radius of notch 60.03 mm
Dimension to bottom of notch 60.03 mm
Distance to notch, L⁄2 61mm
FIG. 1 Standard Vee Notch Charpy Bar Impact Test Specimen
NOTE 1—The symbol t is for the pipe wall thickness.
NOTE 2—Permissible variations for L/2 shall be 61 mm.
FIG. 2 Impact Test Specimen for Ductile Iron Pipe and Tube
NOTE—Permissible variations shall be as follows:
Adjacent sides shall be at 90° 6 10 min
Cross section dimensions 60.03 mm
Length of specimen +0, −2.5 mm
FIG. 3 Unnotched Charpy Bar Impact Test Specimen
A 327M – 91 (2006)
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Copyright by ASTM Int'l (all rights reserved);
Reproduction authorized per License Agreement with Monique Tyree (ASTMIHS Account); Tue Feb 21 11:22:01 EST 2006