ASTM A577/A577M-90(1996)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: A 577/A 577M – 90 (Reapproved 1996)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Specification for
Ultrasonic Angle-Beam Examination of Steel Plates
This standard is issued under the fixed designation A 577/A 577M; 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 4.2 The surface of the plate shall be conditioned as neces-
sary to provide a clear, easily interpreted trace pattern on the
1.1 This specification covers an ultrasonic angle-beam
screen. Any specified identification which is removed to
procedure and acceptance standards for the detection of inter-
achieve proper surface smoothness shall be restored.
nal discontinuities not laminar in nature and of surface imper-
fections in a steel plate. This specification is intended for use
5. Apparatus
only as a supplement to specifications which provide straight-
5.1 The amplitude linearity shall be checked by positioning
beam ultrasonic examination.
the transducer over the depth resolution notch in the IIW or
NOTE 1—An internal discontinuity that is laminar in nature is one
similar block so that the signal from the notch is approximately
whose principal plane is parallel to the principal plane of the plate.
30 % of the screen height, and the signal from one of the back
1.2 Individuals performing examinations in accordance with
surfaces is approximately 60 % of the screen height (two times
this specification shall be qualified and certified in accordance
the height of the signal from the notch). A curve is then plotted
with the requirements of the latest edition of ASNT SNT-
showing the deviations from the above established 2:1 ratio
TC-1A or an equivalent accepted standard. An equivalent
that occurs as the amplitude of the signal from the notch is
standard is one which covers the qualification and certification
raised in increments of one scale division until the back
of ultrasonic nondestructive examination candidates and which
reflection signal reaches full scale, and then is lowered in
is acceptable to the purchaser.
increments of one scale division until the notch signal reaches
1.3 The values stated in either inch-pound units or SI units
one scale division. At each increment the ratio of the two
are to be regarded separately as standard. Within the text, the
signals is determined. The ratios are plotted on the graph at the
SI units are shown in brackets. The values stated in each
position corresponding to the larger signal. Between the limits
system are not exact equivalents; therefore, each system must
of 20 % and 80 % of the screen height the ratio shall be within
be used independently of the other. Combining values from the
10 % of 2:1. Instrument settings used during inspection shall
two systems may result in nonconformance with the specifi-
not cause variation outside the 10 % limits established above.
cation.
5.2 The search unit shall be a 45-deg (in steel) angle-beam
type with active transducer length and width dimensions of a
2. Referenced Documents
minimum of ⁄2 in. [12.5 mm] and a maximum of 1 in. [25
2.1 ASTM Standards:
mm]. Search units of other sizes and angles may be used for
SNT-TC-1A Recommended Practice for Personnel Qualifi-
additional exploration and evaluation.
cation and Certification in Nondestructive Testing
6. Examination Frequency
3. Ordering Information
6.1 The ultrasonic frequency selected for the examination
3.1 The inquiry and order shall indicate any additions to the
shall be the highest frequency that permits detection of the
provisions of this specification as prescribed in 11.1.
required calibration notch, such that the amplitude of the
4. Examination Conditions
indication yields a signal-to-noise ratio of at least 3:1.
4.1 The examination shall be conducted in an area free of
7. Calibration Reflector
operations that interfere with proper performance of the
examination. 7.1 A calibration notch, the geometry of which has been
agreed upon by the purchaser and the manufacturer, with a
depth of 3 % of the plate thickness, shall be used to calibrate
This specification is under the jurisdiction of ASTM Committee A-1 on Steel,
the ultrasonic examination. The notch shall be at least 1 in. [25
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
mm] long.
A01.11 on Steel Plates for Boilers and Pressure Vessels.
7.2 Insert the notch or notches on the surface of the plate so
Current edition approved Dec. 28, 1990. Published May 1991. Originally
published as A 577 – 67 T. Last previous edition A 577/A 577M – 86.
that they are perpendicular to the long axis at a distance of 2 in.
For ASME Boiler and Pressure Vessel Code applications, see related Specifi-
[50 mm] or more from the short edge of the plate. Locate the
cation SA-577/SA-577M in Section II of that Code.
3 notch not less than 2 in. [50 mm] from the long edges of the
Available from American Society for Nondestructive Testing, 1711 Arlingate
Plaza, Columbus, OH 43228. plate.
A 577/A 577M
7.3 When the notch cannot be inserted in the plate to be 8.3.3 Draw a line on the screen connecting the points
tested, it may be placed in a calibration plate of ultrasonically established in 8.3.1 and 8.3.2. This line shall be a DAC for
similar material. The calibration plate will be considered reporting indication amplitudes.
ultrasonically similar if the height of the first back reflection
9. Examination Procedure
through it is within 25 % of that through the plate to be tested
at the same instrument calibration. The calibration plate 9.1 Scan one major surface of the plate on grid lines
perpendicular and parallel to the major rolling direction. Grid
thickness shall be within 1 in. [25 mm] of the thickness of
plates to be tested, for plates of 2 in. [50 mm] thickness and lines shall be on 9-in. [225-mm] centers. Use a suitable
couplant such as water, oil, or glycerin.
...