ASTM A939-96(2001)
(Test Method)Standard Test Method for Ultrasonic Examination from Bored Surfaces of Cylindrical Forgings
Standard Test Method for Ultrasonic Examination from Bored Surfaces of Cylindrical Forgings
SCOPE
1.1 This test method covers a basic procedure of ultrasonically inspecting cylindrical forgings with bores from the bore surface.
1.2 This test method applies to the manual testing mode. It does not restrict the use of other testing modes, such as mechanized or automated.
1.3 This test method applies to cylindrical forgings having bore sizes equal to or greater than 2.5 in. (63.5 mm).
1.4 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 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 and health practices and determine the applicability of regulatory limitations prior to use.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
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Designation:A 939–96 (Reapproved 2001)
Standard Test Method for
Ultrasonic Examination from Bored Surfaces of Cylindrical
Forgings
This standard is issued under the fixed designation A 939; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 The bore ultrasonic inspection shall be performed after
the final austenitizing and tempering heat treatment for me-
1.1 This test method covers a basic procedure of ultrasoni-
chanical properties of the forging, and may be performed either
cally inspecting cylindrical forgings with bores from the bore
prior to or after any subsequent stress relieving heat treatment.
surface.
3.3 The ultrasonic beam shall be introduced radially for
1.2 This test method applies to the manual testing mode. It
overall scanning.
does not restrict the use of other testing modes, such as
3.4 Forgings may be tested either when stationary or while
mechanized or automated.
rotated by means of a lathe or rollers.
1.3 This test method applies to cylindrical forgings having
3.5 To ensure complete coverage of the bore surface, the
bore sizes equal to or greater than 2.5 in. (63.5 mm).
search unit shall be indexed approximately 75 % of the
1.4 The values stated in inch-pound units are to be regarded
transducer width with each pass of the search unit.
as the standard. The values given in parentheses are provided
3.6 A frequency of 2 ⁄4 MHz shall be used unless addi-
for information purposes only.
tional transducer frequencies are specified by the purchaser.
1.5 This standard does not purport to address all of the
3.7 The bore hole diameter and calibration hole(s) shall be
safety concerns, if any, associated with its use. It is the
as specified on the purchaser’s drawing or order.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Pulsed Ultrasonic Reflection Equipment and
bility of regulatory limitations prior to use.
Accessories
2. Significance and Use 4.1 Electronic Apparatus—Apulse echo instrument permit-
ting inspection frequencies of 1, 2.25, and 5 MHz is required.
2.1 This test method shall be used when ultrasonic inspec-
The accuracy of discontinuity amplitude analysis usingthistest
tion from the bore surface is required by the order or
method involves a knowledge of the true operating frequency
specification for inspection purposes in which the acceptance
of the complete inspection system. One of the best ways to
of the forging is based on limitations of the number, amplitude,
obtain the desired accuracy is by use of a tuned pulser and
or location of discontinuities or a combination thereof, which
narrow bans amplifier of known frequency response, with
leads to ultrasonic indications.
either a broad band transducer or a narrow band tuned
2.2 The acceptance criteria shall be stated clearly as order
transducer of known and matching frequency. An equipment
requirements.
calibration plan that is acceptable to both the purchaser and the
2.3 This test method specifies dual search units, which
supplier shall be available.
depending on the angle, are sensitive only to 2 to 3 in. into the
4.2 Amplifier—The amplifier and the cathode ray tube shall
metal from the bore surface.
provide linear response (within 65%)upto1 ⁄2 in. (38.1 mm)
3. General Requirements sweeptopeak.Anequipmentcalibrationplanthatisacceptable
to both the purchaser and the supplier shall be available.
3.1 As far as possible, the entire bore surface shall be
4.3 Signal Attenuator—The instrument shall contain a cali-
subjected to ultrasonic inspection. It may be impossible to
brated gain control or signal attenuator (accurate within 65%
inspect some small portions of the bore surface because of
ineachcase)thatwillallowindicationsbeyondthelinearrange
chamfers at stepdowns and other local configurations.
of the instrument to be measured. It is recommended that these
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