ASTM E588-95

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 588 – 95
Standard Practice for
Detection of Large Inclusions in Bearing Quality Steel by
the Ultrasonic Method
This standard is issued under the fixed designation E 588; 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 E 45 Practice for Determining the Inclusion Content of
Steel
1.1 This practice covers a procedure for the rating of
E 214 Practice for Immersed Ultrasonic Examination by the
rectangular steel sections by immersion ultrasonic techniques.
Reflection Method Using Pulsed Longitudinal Waves
Its purpose is to provide information on the content of large
E 428 Practice for Fabrication and Control of Steel Refer-
inclusions or clusters of small inclusions for determining the
ence Blocks Used in Ultrasonic Inspection
suitability of a steel lot for bearing applications. It should be
E 543 Practice for Evaluating Agencies that Perform Non-
recognized that this method was developed after several years
destructive Testing
of close cooperation between bearing manufacturers and bear-
2 E 1316 Terminology for Nondestructive Examinations
ing steel producers. References (1-8) provide background
2.2 ANSI/ASNT Standards:
information on developmental work. If its use for specification
Recommended Practice SNT-TC-1A Personnel Qualifica-
purposes is contemplated for other steel products, thought
tion and Certification in Nondestructive Testing
should be given to the possibility that a similar cooperative
CP-189 Qualification and Certification of Nondestructive
program between users and steel producers might be necessary.
Testing Personnel
This practice in no manner defines or establishes limits of
2.3 Military Standard:
acceptability.
MIL-STD-410 Nondestructive Testing Personnel Qualifica-
1.2 For this document, large inclusions are defined in
tion and Certification
ultrasonic terms as those having a reflecting area equivalent to
or larger than a 1/64-inch diameter flat-bottom hole in a steel
3. Terminology
reference block of similar properties and thickness. In metal-
3.1 Definitions—For definitions of terms used in this prac-
lographic terms, large inclusions, defined in this way, are of
tice, see Terminology E 1316.
approximately the same size as the smallest detectable sizes
revealed by the macroscopic methods of Practice E 45. In some
4. Basis of Application
cases, inclusions smaller than those described previously can
4.1 Agreements Between Using Parties—In order for this
be detected either individually or in clusters, depending on
practice to be effectively used, the following items require
their type, chemical composition, orientation to the ultrasonic
agreement between the using parties.
beam and distance from the sound entry surface of the
4.1.1 Evaluation of Nondestructive Testing Agencies—An
specimen.
agreement is required as to whether the nondestructive testing
1.3 This standard does not purport to address all of the
agency, as defined in Practice E 543, must be formally evalu-
safety concerns, if any, associated with its use. It is the
ated and qualified to perform the examination. If such an
responsibility of the user of this standard to establish appro-
evaluation is specified, a documented procedure such as
priate safety and health practices and determine the applica-
Practice E 543 shall be used as the basis for evaluation.
bility of regulatory limitations prior to use.
4.1.2 Personnel Qualification—Nondestructive testing
(NDT) personnel shall be qualified in accordance with a
2. Referenced Documents
nationally recognized NDT personnel qualification practice or
2.1 ASTM Standards:
standard such as ANSI/ASNT CP-189, SNT-TC-1A, MIL-
STD-410, or a similar document. The practice or standard used
This practice is under the jurisdiction of ASTM Committee A-1 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee Annual Book of ASTM Standards, Vol 03.01.
A01.28 on Bearing Steels. Annual Book of ASTM Standards, Vol 03.03.
Current edition approved Sept. 10, 1995. Published November 1995. Originally Available from the American Society for Nondestructive Testing, (ASNT),
published as E 588 – 76. Last previous edition E 588 – 88. 1711 Arlingate Plaza, P.O. Box 28518, Columbus, OH 43228.
2 6
Boldface numbers in parentheses refer to the list of references at the end of this Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
practice. Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E588–95
and its applicable revision shall be specified in the contractual 8.2 Ultrasonic Instrument—The ultrasonic instrument shall
agreement between the using parties. be capable of generating and receiving electrical pulses of
4.1.3 Search Unit Performance Tests—Annex A1 defines 10-MHz frequency at levels compatible with the test require-
the minimum manufacturer’s specifications for search units to ments. It shall have both an A-scan presentation and an analog
be used with this practice. The extent of testing and verification output. It shall be the ultrasonic instrument manufacturer’s
of these parameters to be performed by the manufacturer shall responsibility that instruments supplied for use with this test
be specified in the contractual agreement between the using meet the minimum requirements delineated in this recom-
parties. mended practice.
8.2.1 Receiver Characteristics—The center frequency shall
5. Summary of Practice
be 10 6 0.5 MHz. The bandpass of the receiver shall be at least
1.3 MHz (3 dB points).
5.1 The general technique used is immersion ultrasonic
8.2.2 Dynamic Range—The dynamic range of the instru-
testing by the reflection method using pulsed longitudinal
waves such as described in Practice E 214. Specific additional ment shall permit detection of steel balls with a 16-to-1
diameter ratio at a given sensitivity. Balls shall be placed in
requirements for sample preparation, equipment operating
parameters and calibration, and expression of results are water at the focal point of the search unit. Each size ball within
delineated in this procedure. Special focused search units this range shall give a significantly different amplitude of
having operating characteristics as defined in Annex A1 are indication on both the visual oscilloscope presentation and the
required. analog output.
8.2.3 Stability—The analog output voltage of a usable
6. Significance and Use
full-scale indication shall not vary more than 5 % after1hof
instrument warm-up, and preferably by less than 2 % (4-h test
6.1 Comparison with Other Inclusion Rating Methods—
with air temperature being held to 61.2°C over a temperature
Because the test is performed on a volumetric rather than a
range of 17.5 to 25.5°C).
surface-examination basis, the ultrasonic method is inherently
8.2.4 Sweep Length and Linearity—Sweep length of oscil-
better able to detect infrequently occurring large inclusions or
clusters of small inclusions than eddy current, magnetic par- loscope presentation shall be capable of being adjusted to
represent 1 mm = 1.27 mm of steel. A minimum of 80 mm of
ticle, microscopical, or macroscopic examination procedures.
6.2 Limitation of Inclusion Size and Type—A limitation of the sweep display shall be linear to within 5 % of full scale.
Analog output voltage of an indication from a target shall not
the method is that it will not detect all inclusions. Inclusion
chemistry, size, shape, location, and distribution may limit the vary more than 64 % over the gated portion of the sweep
ability of the method to provide indications distinct from those employed in calibration and testing.
generated by the surrounding metallurgical structure. The
8.2.5 Repetition Rate—The repetition rate of the pulser
recommended practice is only meaningfully applicable to
shall not be less than 500 pulses per second.
examination of steel wherein the inclusion size and type are
8.3 Search Units—Ultrasonic search units for this test shall
within the detection capabilities of the method. For steel
be spherically focused immersion-type units. Uniform perfor-
wherein inclusion size, dispersion, and chemistry prevent
mance characteristics of search units are critical for obtaining
optimum inclusion detection by ultrasonics, microscopical
reproducible test measurements. (See Annex A1, which delin-
methods detailed in Practice E 45 may be applied.
eates search unit performance characteristics to be met by
search unit manufacturers.) Performance characteristics of
7. Interference
search units requiring consideration are: the uniformity of focal
distance in water, center frequency, frequency spectrum, lens
7.1 Reflections from Multiple Inclusions—An ultrasonic
radius, width of field, and beam symmetry.
indication can represent the reflection from a single inclusion;
however, it typically represents the vector summation of 8.3.1 Focal Length—A focused beam of radiated ultrasonic
reflections from clusters of small inclusions contained within a energy is recommended to provide lateral resolution of small
volume of a few cubic millimetres. defects and to improve testing sensitivity in the region near the
7.2 Response as a Function of Inclusion Type—The indi- focal point. The focal length of a search unit is defined in this
vidual inclusion reflections can have different amplitudes discussion as the distance in water, on the search unit axis,
because of different inclusion characteristics. In addition, the between the search unit and the surface of a ⁄2 -in. or 12-mm
individual reflections may have different phase characteristics diameter ball target at which the highest reflection amplitude
when arriving at the search unit if the travel distances are indication is obtained. Different focal length transducers may
different.
be used to obtain optimum response at selected distances below
the test sample surface. (Variation of search unit-to-specimen
8. Apparatus
surface water path would also affect the focal point within the
test sample.)
8.1 Equipment Required—An equipment system with the
8.3.2 Search Unit Characteristics—Search units generally
following components is needed to conduct this test: ultrasonic
employed have the following frequency and focal length as
test instrument, search unit, a means of recording signals of
purchased:
various amplitudes, a system reference block, instrument
calibration block, and an immersion tank with suitable scan- Frequency Focal Length in Water
10 6 0.5 MHz 8.2 6 0.3 in (208.3 6 7.6 mm)
ning accessories.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E588–95
A search unit shall be discarded as no longer fit for use when pulse counters, both repetition rate and scanning speed must be
held within a 5 % tolerance and, preferably, 2 %.
its focal length has degenerated to 7.5 in. (190.5 mm).
8.6 System Reference Block—A system reference block of 4
8.3.3 Beam Symmetry—Each search unit should be rotated
by 4-in. (102 by 102-mm) cross section is required for initial
on its ultrasonic beam axis (not necessarily geometric axis)
adjustments and operational testing of the equipment. This
until a particular circumferential orientation is found which
sample should be selected to provide reflection signals at all
gives a maximum severity, or count, from the system reference
counting levels. Depth distribution of inclusions in the selected
block. This search unit orientation shall be identified and
reference block should make its response characteristics rela-
employed in subsequent tests. Search units that exhibit varia-
tively insensitive to minor focal length variations between
tions in indication amplitude in excess of 15 % during rotation
different search units. The reference block should give a
shall not be considered satisfactory for the test. There are other
minimum change in total counts of 10 % for each 10 %
methods, such as optimum response over a precision and
increase or decrease in amplitude setting. A maximum of 30 %
uniform taut wire, that have been found to be usable.
change in count for each 10 % change in amplitude setting
8.3.4 Performance—The performance capabilities of all
should not be exceeded. It should be suitably protected from
new search units shall be verified by an actual test on the
corrosion to assure its longevity. Thermal conditioning and
system reference block. The data obtained for new search units
surface preparation should conform with the particular test
should be compared with that obtained for other search units
method. This block may also serve as a secondary reference
having the same specifications and tested under identical
standard if flat-bottom holes are drilled in accordance with hole
conditions.
specifications defined in Practice E 428. Holes drilled at
8.4 Immersion Tank and Accessories—An immersion tank
various depths beneath the entry surface permit distance
with associated scanning and indexing facilities shall be used.
amplitude correction when desired.
8.4.1 Search Unit Angulation—The tank shall be provided
with a manipulator capable of continuously angulating the
9. Test Specimens
search unit in two vertical mutually perpendicular planes
9.1 General—Test specimens are obtained from wrought
permitting the required normalization.
billets and may be either in the rolled or forged condition.
8.4.2 Scanning and Indexing—The tank bridge and carriage
Unless otherwise agreed upon, specimens shall be taken from
assemblies shall provide X-Y motion to the search unit. The
the first, middle, and last portion of the heat as agreed upon
scanning shall be parallel or perpendicular (depending on the
between the supplier and the purchaser.
procedure) to the test specimen axis and the indexing shall be
9.2 Specimen Size and Shape—Specimens shall have a
perpendicular to the scanning.
minimum cross-sectional dimension after preparation of 3 ⁄2 in.
8.4.3 Test Specimen Mounting—The tank shall be provided
(88.9 mm). The area scanned shall be sufficient to permit
with fixturing permitting the mounting of the entry surface of
3 3
testing of a minimum of 25 in. (410 cm ) of the specimen. The
the test specimen parallel to the bridg
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