ASTM E1001-99a
(Practice)Standard Practice for Detection and Evaluation of Discontinuities by the Immersed Pulse-Echo Ultrasonic Method Using Longitudinal Waves
Standard Practice for Detection and Evaluation of Discontinuities by the Immersed Pulse-Echo Ultrasonic Method Using Longitudinal Waves
SCOPE
1.1 This practice describes procedures for the ultrasonic examination of bulk materials or parts by transmitting pulsed, longitudinal waves through a liquid couplant into the material and observing the indications of reflected waves (Fig. 1). It covers only examinations in which one search unit is used as both transmitter and receiver (pulse-echo) and in which the part or material being examined is totally submerged in the couplant (immersion testing). This practice includes general requirements and procedures which may be used for detecting discontinuities and for making a relative or approximate evaluation of the size of discontinuities.
1.2 This practice complements Practice E214 by providing more detailed procedures for the selection and calibration of the inspection system and for evaluation of the indications obtained.
1.3 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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Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.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 1001 – 99a
Standard Practice for
Detection and Evaluation of Discontinuities by the
Immersed Pulse-Echo Ultrasonic Method Using Longitudinal
Waves
This standard is issued under the fixed designation E 1001; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope E 317 Practice for Evaluating Performance Characteristics
of Ultrasonic Pulse-Echo Testing Systems Without the Use
1.1 This practice describes procedures for the ultrasonic
of Electronic Measurement Instruments
examination of bulk materials or parts by transmitting pulsed,
E 428 Practice for Fabrication and Control of Steel Refer-
longitudinal waves through a liquid couplant into the material
ence Blocks Used in Ultrasonic Inspection
and observing the indications of reflected waves (Fig. 1). It
E 1316 Terminology for Nondestructive Examinations
covers only examinations in which one search unit is used as
2.2 ASNT Documents:
both transmitter and receiver (pulse-echo) and in which the part
SNT-TC-1A Recommended Practice for Personnel Qualifi-
or material being examined is totally submerged in the cou-
cation and Certification in Nondestructive Testing
plant (immersion testing). This practice includes general re-
ANSI/ASNT-CP-189 Standard for Qualification and Certi-
quirements and procedures which may be used for detecting
fication of Nondestructive Testing Personnel
discontinuities and for making a relative or approximate
2.3 Military Standards:
evaluation of the size of discontinuities.
MIL-STD-410E Nondestructive Testing Personnel Qualifi-
1.2 This practice complements Practice E 214 by providing
cation and Certification (Eddy-Current, Liquid Penetrant,
more detailed procedures for the selection and calibration of
Magnetic Particle, Radiographic, and Ultrasonic)
the inspection system and for evaluation of the indications
NAS-410 Nondestructive Testing Personnel Qualification
obtained.
and Certification
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions:
priate safety and health practices and determine the applica-
3.1.1 For definitions of terms used in this practice, see
bility of regulatory limitations prior to use.
Terminology E 1316.
2. Referenced Documents 3.2 Definitions of Terms Specific to This Standard:
3.2.1 effective beam diameter—that distance through which
2.1 ASTM Standards:
a search unit can be traversed across a calibration reflector so
C 1212 Practice for Fabricating Ceramic Reference Speci-
2 that the corresponding echo amplitude is at least one half (-6
mens Containing Seeded Voids
dB) of the maximum amplitude. The effective beam diameter is
C 1336 Practice for Fabricating Non-Oxide Ceramic Refer-
2 not a characteristic of the search unit alone, but is dependent on
ence Specimens Containing Seeded Inclusions
propagating medium, distance to the discontinuity, reflector
E 127 Practice for Fabricating and Checking Aluminum
geometry, etc.
Alloy Ultrasonic Standard Reference Blocks
3.2.2 evaluation—the determination of the relative or ap-
E 214 Practice for Immersed Ultrasonic Examination by the
proximate size of a discontinuity, or its indication amplitude
Reflection Method Using Pulsed Longitudinal Waves
relative to the amplitude of a reference discontinuity.
3.2.3 examination—the automatic or manual scanning of a
part to locate discontinuities.
This practice is under the jurisdiction of ASTM Committee E-7 on Nonde-
structive Testing and is the direct responsibility of Subcommittee E07.06 on
Ultrasonic Testing Procedure.
Current edition approved Aug. 10, 1999. Published October 1999. Originally Available from American Society for Nondestructive Testing, 1711 Arlingate
published as E 1001 – 84. Last previous edition E 1001 – 99. Plaza, P.O. Box 28518, Columbus, OH 43228-0518.
2 5
Annual Book of ASTM Standards, Vol 15.01. Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
Annual Book of ASTM Standards, Vol 03.03. 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.
E 1001 – 99a
FIG. 1 Basic Immersion Setup
3.2.4 gain—the amount of amplification or attenuation, or signals at frequencies in the range of search unit frequencies
both, applied to an electrical signal that dictates its amplitude being used. The equipment and its display should be capable of
as displayed on the cathode-ray tube (CRT). meeting the requirements to be completed in Table 1, as agreed
3.2.5 scan index—the length of the step created by rastering upon between the supplier and the purchaser, and as measured
the search unit over the part, that is continuously scanning in in accordance with procedures described in Practice E 317 or
one direction, then stepping in the direction perpendicular to equivalent procedures (see Note 1). These requirements are
the scan. The allowable scan index should be correlated with applicable only for the frequencies required for the inspection.
the search unit effective beam diameter to ensure full coverage Also, the equipment, including the search unit, should be
of the part. capable of producing echo amplitudes of at least 60 %, of full
3.2.6 standardize—to adjust the gain of an ultrasonic instru- scale, with the noise level no greater than 20 %, from the
ment so that the amplitude of the echo from a specified appropriate reference reflector at a material distance equal to
reference reflector is a specified value. the thickness of the part to be inspected. Alternatively, if these
3.2.7 transfer—a change in scanning gain to compensate for conditions can be met at one half the part thickness, the part
differences in attenuation of the reference blocks and the part may be inspected from both sides.
or material being inspected.
NOTE 1—Significantly higher frequencies than those shown in Table 1
(for example, 50 MHz) may be necessary for the smaller critical flaw size
4. Summary of Practice
of advanced ceramics.
4.1 This practice describes a means for obtaining an evalu-
6.2 Voltage Regulator—If fluctuations in line voltage cause
ation of discontinuities in materials by immersed examination
variations exceeding 65 % of the vertical limit in an indication
with longitudinal ultrasonic waves. Equipment, reference stan-
with an amplitude of one half the vertical limit, a voltage
dards, examination and evaluation procedures, and documen-
regulator should be required on the power source. This
tation are described in detail.
requirement is not applicable to battery-operated units.
6.3 Search Units—The search unit selected should be com-
5. Significance and Use
patible with the electronic equipment being used and with the
5.1 This practice provides guidelines for the application of
material to be inspected. The search units should be of the
immersed longitudinal wave examination to the detection and
quantitative evaluation of discontinuities in materials.
TABLE 1 Minimum Equipment Requirements (Longitudinal Wave)
5.2 Although not all requirements of this practice can be
Ultrasonic Test
applied universally to all inspection situations and materials, it
Frequency, MHz
Instrument Characteristics
does provide a basis for establishing contractual criteria
2.25 5.0 10.0 15.0
between suppliers and purchasers of materials for performing
Vertical limit, in. (mm), trace to peak or percent of full
immersed pulse-echo examination, and may be used as a
screen height
general guide for writing detailed specifications for particular
Upper linearity limit, in. (mm), trace to peak or percent
of full screen height
applications.
Lower linearity limit, in. (mm), trace to peak or percent
5.3 This practice is directed towards the evaluation of
of full screen height
discontinuities detectable at normal beam incidence. If discon-
Ultrasonic sensitivity, reflector size, material distance,
in. (mm)
tinuities at other orientations are of concern, alternate scanning
Signal-to-noise ratio
techniques are required.
Entry surface resolution, in. (mm)
Back surface resolution, in. (mm)
6. Apparatus Horizontal limit, in. (mm) or percent of full screen width
Horizontal linearity range, in. (mm) or percent of full
6.1 Electronic Equipment—The electronic equipment
screen width
should be capable of producing and processing electronic
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.
E 1001 – 99a
immersion type. Only straight-beam (longitudinal) search 6.7.1 Flat Blocks—The three most commonly used sets of
units, with flat or focused acoustic lenses, should be used. reference blocks are (1) area-amplitude blocks, containing
Focused or dual element search units may provide better blocks with the same material path and various sizes of
near-surface resolution and detection of small discontinuities. reference reflectors; (2) distance-amplitude blocks containing
Generally, round or rectangular search units are used for blocks with one-size reference reflector at various material
examination whereas round search units with symmetrical paths; and (3) a combination including both area-amplitude and
sound beam patterns are used for evaluation. distance-amplitude blocks in one set. These sets are described
6.4 Alarm—For the examination of parts or material with in Practice E 127. However, other types of reference blocks
regular shape and parallel surfaces, such as plate, machined bar may be used when mutually agreed upon between the supplier
stock, and forgings, an audible alarm should be used in and the purchaser, for example, those given in Practice E 428.
preference to a visual alarm, since the examination process can Practices C 1212 and C 1336 containing seeded voids and
be accomplished at a speed which prevents reliable visual seeded inclusions may be used for advanced ceramics.
monitoring of the instrument screen. As a matter of practicality, 6.7.2 Curved Surfaces—Reference blocks with flat surfaces
an audible alarm should be used in conjunction with visual may be used for establishing gain settings for examinations on
monitoring wherever possible. The alarm should be adjustable test surfaces with radii of curvature 5 in. (130 mm) or greater.
For test surfaces with radii of curvature less than 5 in.,
to allow triggering at any commonly required level of indica-
tion amplitude and depth of material. During operation the reference blocks with the same nominal curvature should be
used, unless otherwise agreed upon between the supplier and
audible or visible signal produced by the alarm should be easily
detectable by the operator. the purchaser.
6.8 Reference Reflectors—Flat-bottom holes, (FBH), or
NOTE 2—This requirement may not be applicable if recording equip-
other artificial discontinuities, located either directly in the test
ment is used.
part or material, in a representative sample of the part or
6.4.1 Alarm Gate Synchronization—To ensure that the
material, or in reference blocks, should be used to establish the
alarm gate tracks the inspection area, the gate should lock on
reference echo amplitude or to perform distance-amplitude
the first interface pulse from the test piece rather than on the
correction, or both. For most examinations, the bottom surface
initial pulse from the system. Gating from the initial pulse can
of a suitable diameter flat-bottom hole is the common reference
result in either partial loss of the inspection area from the gate,
reflector. However, other types of artificial discontinuities
or the inclusion of the back reflection and interface signal in the
(notches, side-drilled holes, etc.) may be used when mutually
gated area. This will trigger the gate as would an imperfection.
agreed upon between the supplier and the purchaser. Seeded
6.5 Manipulating Equipment should be provided to ad-
voids (Practice C 1212), seeded inclusions (Practice C 1336),
equately support a search tube, containing the search unit, and
and laser-drilled holes are common reflectors for advanced
to allow angular adjustment in two mutually perpendicular,
ceramics.
vertical planes. A manipulator may be attached between the
7. General Examination Requirements
search tube and search unit to provide the necessary angular
adjustments. The scanning and indexing apparatus should have
7.1 Material Condition—Perform ultrasonic examination of
sufficient structural rigidity to provide support for the manipu- parts or material before machining if surface roughness and
lator and should allow smooth, accurate positioning of the
part geometry are within the tolerance specified in the contrac-
search unit. This apparatus should permit control of the scan in tual agreement. Surfaces may already be sufficiently free of
accordance with 8.3.1 and control of the index in accordance
roughness and waviness to permit a uniform examination over
with 8.2.1. Also, the scanning apparatus should be sufficiently the required areas. When it is determined that surface rough-
rigid to keep search unit backlash to within tolerances as
ness precludes adequate detection and evaluation of subsurface
specified in the contractual agreement. Water-path distances discontinuities, smooth the areas in question by machining,
should be continuously adjustable.
grinding, or other means before the examination is performed.
6.6 Tank—The container or tank should permit accurate For advanced ceramics, care should be taken to avoid gener-
positioning of the search unit, reference blocks, and part or
ating surface or near-surface cracks by the smoothing opera-
material to be examined in accordance with the requirements of tion. During examination and evaluation, ensure that the entry
Section 7. surface and back surface are free of loose scale, machining, or
6.7 Reference Artifacts—Ultrasonic reference blocks, often grinding particles or other loose foreign matter.
called test blocks or reference specimens, are used to standard- 7.2 Coverage—In all examinations, perform scanning to
ize the ultrasonic equipment and to evaluate the indications locate disc
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