ASTM A939-07
(Test Method)Standard Practice for Ultrasonic Examination from Bored Surfaces of Cylindrical Forgings
Standard Practice for Ultrasonic Examination from Bored Surfaces of Cylindrical Forgings
SIGNIFICANCE AND USE
This practice shall be used when ultrasonic inspection from the bore surface is required by the order or specification for inspection purposes in which the acceptance of the forging is based on limitations of the number, amplitude, or location of discontinuities or a combination thereof, which leads to ultrasonic indications.
The acceptance criteria shall be stated clearly as order requirements.
This practice specifies dual search units, which depending on the angle, are sensitive only to 2 to 3 in. into the metal from the bore surface.
SCOPE
1.1 This practice covers a basic procedure of ultrasonically inspecting cylindrical forgings with bores from the bore surface.
1.2 This practice applies to the manual testing mode. It does not restrict the use of other testing modes, such as mechanized or automated.
1.3 This practice 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 standard. The values given in parentheses are mathematical conversion to SI units that are provided for information only and are not considered standard.
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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Designation:A939–07
Standard Practice for
Ultrasonic Examination from Bored Surfaces of Cylindrical
1
Forgings
This standard is issued under the fixed designation A939; 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 (´) 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 practice covers a basic procedure of ultrasonically
chanical properties of the forging, and may be performed either
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 practice applies to the manual testing mode. It does
overall scanning.
not restrict the use of other testing modes, such as mechanized
3.4 Forgings may be tested either when stationary or while
or automated.
rotated by means of a lathe or rollers.
1.3 This practice applies to cylindrical forgings having bore
3.5 To ensure complete coverage of the bore surface, the
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 standard. The values given in parentheses are mathematical
1
3.6 Afrequency of 2 ⁄4 MHz shall be used unless additional
conversions to SI units that are provided for information only
transducer frequencies are specified by the purchaser.
and are not considered standard.
3.7 The bore hole diameter and calibration hole(s) shall be
1.5 This standard does not purport to address all of the
as specified on the purchaser’s drawing or order.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Pulsed Ultrasonic Reflection Equipment and
priate safety and health practices and determine the applica-
Accessories
bility of regulatory limitations prior to use.
4.1 Electronic Apparatus—Apulse echo instrument permit-
2. Significance and Use ting inspection frequencies of 1, 2.25, and 5 MHz is required.
The accuracy of discontinuity amplitude analysis using this
2.1 This practice shall be used when ultrasonic inspection
practice involves a knowledge of the true operating frequency
from the bore surface is required by the order or specification
of the complete inspection system. One of the best ways to
for inspection purposes in which the acceptance of the forging
obtain the desired accuracy is by use of a tuned pulser and
is based on limitations of the number, amplitude, or location of
narrow band amplifier of known frequency response, with
discontinuities or a combination thereof, which leads to ultra-
either a broad band transducer or a narrow band tuned
sonic indications.
transducer of known and matching frequency. An equipment
2.2 The acceptance criteria shall be stated clearly as order
calibration plan that is acceptable to both the purchaser and the
requirements.
supplier shall be available.
2.3 This practice specifies dual search units, which depend-
4.2 Amplifier—The amplifier and the cathode ray tube shall
ing on the angle, are sensitive only to 2 to 3 in. into the metal
1
provide linear response (within 65%)upto1 ⁄2 in. (38.1 mm)
from the bore surface.
sweeptopeak.Anequipmentcalibrationplanthatisacceptable
3. General Requirements
to both the purchaser and the supplier shall be available.
4.3 Signal Attenuator—The instrument shall contain a cali-
3.1 As far as possible, the entire bore surface shall be
brated gain control or signal attenuator (accurate within 65%
subjected to ultrasonic inspection. It may be impossible to
ineachcase)thatwillallowindicationsbeyondthelinearrange
inspect some small portions of the bore surface because of
of the instrument to be measured. It is recommended that these
chamfers at stepdowns and other local configurations.
controls permit signal adjustment up to 25 to 1 (28 dB).
4.4 Search Units—Dual longitudinal wave search units of
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This practice is under the jurisdiction of ASTM Committee A01 on Steel,
known effective frequency should be used for scanning. Each
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
1
A01.06 on Steel Forgings and Billets. ⁄4- by 1-in. (6.35 by 25.4-mm) 2.25 MHz transducer, used with
Current edition approved May 1, 2007. Published May 2007. Originally
the 1-in. dimension parallel to the longitudinal axis of the
approved in 1995. Last previous edition approved in 2006 as A939 – 96 (2006).
forging, will provide a desirabl
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