ASTM A577/A577M-90(2001)
(Specification)Standard Specification for Ultrasonic Angle-Beam Examination of Steel Plates
Standard Specification for Ultrasonic Angle-Beam Examination of Steel Plates
SCOPE
1.1 This specification covers an ultrasonic angle-beam procedure and acceptance standards for the detection of internal discontinuities not laminar in nature and of surface imperfections in a steel plate. This specification is intended for use only as a supplement to specifications which provide straight-beam ultrasonic examination.
Note 1--An internal discontinuity that is laminar in nature is one whose principal plane is parallel to the principal plane of the plate.
1.2 Individuals performing examinations in accordance with this specification shall be qualified and certified in accordance with the requirements of the latest edition of ASNT SNT-TC-1A or an equivalent accepted standard. An equivalent standard is one which covers the qualification and certification of ultrasonic nondestructive examination candidates and which is acceptable to the purchaser.
1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.
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Designation: A 577/A 577M – 90 (Reapproved 2001)
Standard Specification for
Ultrasonic Angle-Beam Examination of Steel Plates
This standard is issued under the fixed designationA577/A577M; 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. Ordering Information
1.1 This specification covers an ultrasonic angle-beam 3.1 The inquiry and order shall indicate any additions to the
procedure and acceptance standards for the detection of inter- provisions of this specification as prescribed in 11.1.
nal discontinuities not laminar in nature and of surface imper-
4. Examination Conditions
fections in a steel plate. This specification is intended for use
only as a supplement to specifications which provide straight- 4.1 The examination shall be conducted in an area free of
operations that interfere with proper performance of the
beam ultrasonic examination.
examination.
NOTE 1—An internal discontinuity that is laminar in nature is one
4.2 The surface of the plate shall be conditioned as neces-
whose principal plane is parallel to the principal plane of the plate.
sary to provide a clear, easily interpreted trace pattern on the
1.2 Individualsperformingexaminationsinaccordancewith
screen. Any specified identification which is removed to
this specification shall be qualified and certified in accordance
achieve proper surface smoothness shall be restored.
with the requirements of the latest edition of ASNT SNT-
TC-1A or an equivalent accepted standard. An equivalent 5. Apparatus
standard is one which covers the qualification and certification
5.1 The amplitude linearity shall be checked by positioning
of ultrasonic nondestructive examination candidates and which
the transducer over the depth resolution notch in the IIW or
is acceptable to the purchaser.
similar block so that the signal from the notch is approximately
1.3 The values stated in either inch-pound units or SI units
30 % of the screen height, and the signal from one of the back
are to be regarded separately as standard. Within the text, the
surfaces is approximately 60 % of the screen height (two times
SI units are shown in brackets. The values stated in each
the height of the signal from the notch).Acurve is then plotted
system are not exact equivalents; therefore, each system must
showing the deviations from the above established 2:1 ratio
be used independently of the other. Combining values from the
that occurs as the amplitude of the signal from the notch is
two systems may result in nonconformance with the specifi-
raised in increments of one scale division until the back
cation.
reflection signal reaches full scale, and then is lowered in
increments of one scale division until the notch signal reaches
2. Referenced Documents
one scale division. At each increment the ratio of the two
2.1 ASTM Standards:
signals is determined. The ratios are plotted on the graph at the
SNT-TC-1A Recommended Practice for Personnel Qualifi-
position corresponding to the larger signal. Between the limits
cation and Certification in Nondestructive Testing
of 20 % and 80 % of the screen height the ratio shall be within
10 % of 2:1. Instrument settings used during inspection shall
not cause variation outside the 10 % limits established above.
This specification is under the jurisdiction of ASTM Committee A-1 on Steel,
5.2 The search unit shall be a 45-deg (in steel) angle-beam
Stainless Steel, and RelatedAlloys and is the direct responsibility of Subcommittee
A01.11 on Steel Plates for Boilers and Pressure Vessels.
type with active transducer length and width dimensions of a
Current edition approved Dec. 28, 1990. Published May 1991. Originally
minimum of ⁄2 in. [12.5 mm] and a maximum of 1 in. [25
published as A 577 – 67 T. Last previous edition A 577/A 577M – 86.
2 mm]. Search units of other sizes and angles may be used for
For ASME Boiler and Pressure Vessel Code applications, see related Specifi-
cation SA-577/SA-577M in Section II of that Code. additional exploration and evaluation.
Available from American Society for Nondestructive Testing, 1711 Arlingate
Plaza, Columbus, OH 43228.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A 577/A 577M – 90 (2001)
6. Examination Frequency 8.2.2 Without adjusting the instrument settings, reposition
the search unit to obtain a maximum full vee-path indication
6.1 The ultrasonic frequency selected for the examination
from the notch on the test surface. Record the location and
shall be the highest frequency that permits detection of the
amplitude on the screen.
required calibration notch, such that the amplitude of the
8.2.3 Draw a line on the screen connecting the points
indication yields a signal-to-noise ratio of at least 3:1.
established in 8.2.1 and 8.2.2. This curve shall be a DAC for
reporting indication amplitudes.
7. Calibration Reflector
8.3 Plate over 6 in. [150 mm] in Thickness:
7.1 A calibration notch, the geometry of which has been
8.3.1 Place the search unit on the test surface aimed at the
agreed upon by the purchaser and the manufacturer, with a
broad side of the notch on the opposite surface of the plate.
depth of 3 % of the plate thickness, shall be used to calibrate
Positionthesearchunittoobtainamaximumone-halfvee-path
the ultrasonic examination. The notch shall be at least 1 in. [25
indication amplitude. Adjust the instrument gain so that this
mm] long.
amplitudeisatleast50 %butnotmorethan80 %offullscreen
7.2 Insert the notch or notches on the surface of the plate so
height. Record the location and amplitude on the screen.
that they are perpendicular to the long axis at a distance of 2 in.
8.3.2 Without adjusting the instrument settings, reposition
[50 mm] or more from the short edge of the plate. Locate the
the search unit to obtain a maximum full vee-path indication
notch not less than 2 in. [50 mm] from the long edges of the
from the notch on the test surface. Record the location and
plate.
amplitude on the screen.
7.3 When the notch cannot be inserted in the plate to be
8.3.3 Draw a line on the scre
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