ASTM B548-03(2017)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B548 − 03 (Reapproved 2017)
Standard Test Method for
Ultrasonic Inspection of Aluminum-Alloy Plate for Pressure
Vessels
This standard is issued under the fixed designation B548; 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 ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 Thistestmethodcoverspulse-echoultrasonicinspection
mendations issued by the World Trade Organization Technical
of aluminum-alloy plate of thickness equal to or greater than
Barriers to Trade (TBT) Committee.
0.500 in. (12.7 mm) for use in the fabrication of pressure
vessels. The ultrasonic test is employed to detect gross internal
2. Referenced Documents
discontinuities oriented in a direction parallel to the rolled
2.1 The following documents of the issue in effect on date
surface such as cracks, ruptures, and laminations, and to
of material purchase form a part of this specification to the
provide assurance that only plate that is free from rejectable
extent referenced herein:
discontinuities is accepted for delivery.
2.2 ASTM Standards:
1.2 The inspection method and acceptance criteria included
E114 Practice for Ultrasonic Pulse-Echo Straight-Beam
in this standard shall be limited to plate of the following
Contact Testing
aluminum alloys: 1060, 1100, 3003,Alclad 3003, 3004,Alclad
E214 Practice for Immersed Ultrasonic Testing by the Re-
3004, 5050, 5052, 5083, 5086, 5154, 5254, 5454, 5456, 5652,
flection Method Using Pulsed Longitudinal Waves (With-
6061, and Alclad 6061.
drawn 2007)
1.3 This test method applies only to ultrasonic tests using
E317 Practice for Evaluating Performance Characteristics of
pulsed longitudinal waves which are transmitted and received
Ultrasonic Pulse-Echo Testing Instruments and Systems
by a search unit containing either a single crystal or a
without the Use of Electronic Measurement Instruments
combination of electrically interconnected multiple crystals.
2.3 Other Standards:
Ultrasonic tests employing either the through-transmission or
ASNT Recommended Practice for Nondestructive Testing
the angle-beam techniques are not included.
Personnel Qualification and Certification—Ultrasonic
1.4 This test method shall be used when ultrasonic inspec-
Testing Method—SNT-TC-1A
tion as prescribed herein is required by the contract, purchase
3. Summary of Method
order, or referenced plate specification.
3.1 The plate is inspected ultrasonically by scanning one
1.5 The values stated in inch-pound units are to be regarded
rolled surface with a beam of pulsed longitudinal waves which
as standard. The values given in parentheses are mathematical
is oriented in a direction perpendicular to the entry surface of
conversions to SI units that are provided for information only
the plate. The ultrasound is transmitted into the plate either by
and are not considered standard.
the direct contact, immersion, or liquid-column coupling
1.6 This standard does not purport to address all of the
method. During the scan, an indication representing the first
safety concerns, if any, associated with its use. It is the
back reflection is observed on the A-scan screen of the test
responsibility of the user of this standard to establish appro-
instrument.
priate safety and health practices and determine the applica-
3.2 When the test system sensitivity level is appropriately
bility of regulatory limitations prior to use.
adjusted, a discontinuity is detected during the scan by noting
1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This test method is under the jurisdiction of ASTM Committee B07 on Light Standards volume information, refer to the standard’s Document Summary page on
Metals and Alloys and is the direct responsibility of Subcommittee B07.03 on theASTM website.
Aluminum Alloy Wrought Products. The last approved version of this historical standard is referenced on
Current edition approved July 1, 2017. Published July 2017. Originally approved www.astm.org.
in 1971. Last previous edition approved in 2009 as B548 – 03 (2009). DOI: AvailablefromAmericanSocietyforNondestructiveTesting(ASNT),P.O.Box
10.1520/B0548-03R17. 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B548 − 03 (2017)
NOTE 2—For control purposes, the performance characteristics of the
an isolated indication associated with a loss of the first back
test instrument and search unit may be established in accordance with
reflection indication. The apparent size of the discontinuity is
procedures outlined in Practice E317.
determined by measuring the total area in the scanned entry
surface of the plate where the isolated indication and the loss 5.3 Tank—Fortestsbytheimmersionmethod,anycontainer
of back reflection persist. The estimated discontinuity size and is satisfactory that will facilitate the accurate, stable position-
location are then compared with suitable acceptance criteria. ing of both the search unit and the plate to be inspected.
NOTE 1—Additional information describing ultrasonic tests by the
5.4 Scanning Apparatus—During the inspection procedure,
direct contact method and by the immersion method is available in
the search unit is supported by any one of the following
Practices E114 and E214.
devices. The scanning apparatus shall permit measurement of
both the scan distance and the index distance within 60.1 in.
4. Significance and Use
(62 mm).
4.1 A number of factors such as the condition of the entry
5.4.1 ManipulatorandBridge—When a manipulator is used
and back surfaces of the plate, the inclination of the ultrasonic
in tests by the immersion method, the manipulator shall
beam with respect to the entry surface, and the performance
adequately support a search tube containing a search unit and
characteristics of the test system may cause either a reduction
shall provide fine adjustment of angle within 1° in two vertical
of isolated indications or a substantial loss of back reflection
planes that are perpendicular to each other. The bridge shall be
and thereby could seriously impair the reliability of the test
of sufficient strength to provide rigid support for the manipu-
procedure outlined in this standard.
lator and shall allow smooth, accurate positioning of the search
4.2 Accurate evaluations of discontinuity size also may be
unit. Special search unit supporting fixtures may be used
limited significantly by variations in beam characteristics
provided they meet the requirements prescribed for a manipu-
which exist in most search units. For this reason, discontinuity
lator and bridge.
sizeasdeterminedbythetestprocedureoutlinedinthismethod
5.4.2 Liquid Coupling Nozzle—For tests by the liquid-
is regarded as “apparent” or “estimated” in recognition of the
column coupling method, the nozzle is usually positioned
limited quantitative value of the measurement.
manually and shall be capable of containing the couplant while
4.3 Because a large number of interacting variables in a test
rigidly supporting the search unit with its active surface
system can adversely influence the results of an ultrasonic test,
immersed in the couplant. The couplant distance shall be
the actual quantitative effects of detected discontinuities upon
maintained so that the second couplant reflection is to the right
the mechanical properties of the inspected plate are difficult to
of the first back reflection on the instrument cathode ray tube
establish. Consequently, this ultrasonic inspection method is
(CRT). The couplant path shall not vary more than 6 ⁄4 in.
not applicable as an exclusive indicator of the ultimate quality
(6.4 mm) during calibration, initial scanning, and discontinuity
and performance of pressure vessels but provides a reliable
evaluation. The recommended minimum inside dimension of
control of plate quality to avoid failure during the forming
the nozzle is 1.0 in. (25 mm) greater than the maximum
process for fabrication of vessels.
dimension of the crystal surface in the search unit. Provisions
also should be included for adjustment of search unit inclina-
5. Apparatus
tion within 1° in two vertical planes that are perpendicular to
5.1 Test Instrument—Any electronic device that produces
each other.
pulsed longitudinal waves and displays ultrasonic reflections
NOTE 3—Nozzles containing either sealed or unsealed openings may be
on an A-scan indicator when used with an appropriate search
used for inspecting plate provided the test results obtained with either
unit is satisfactory. The instrument shall provide stable, linear
device are equivalent to those obtained by the immersion method.
amplificationofreceivedpulsesataselectedtestfrequencyand
shallbefreefromsignificantinterfacesignalinterferenceatthe 5.4.3 Contact Scanning Unit—During tests by the contact
method, the search unit usually is supported and positioned
required sensitivity level.
manually on the entry surface of the inspected plate. However,
5.2 Search Unit—The search unit recommended for this
special fixtures for contact scanning may be employed pro-
standard is the flat nonfocusing type, and contains a piezoelec-
vided their use ensures conformance to the requirements in this
tric crystal which generates and receives longitudinal waves at
specification.
the rated frequency when connected to the test instrument
through a suitable coaxial cable. A dual-crystal search unit
5.5 Couplant—Clean, deaerated water at room temperature
containing both a transmitting and a receiving crystal in one
is the recommended couplant for tests either by the immersion
container may be used provided the test instrument will
method or by the liquid-column coupling technique. Inhibitors
accommodate two-crystal operation and the resulting pulse-
or wetting agents or both may be used. For tests by the contact
echo test is equivalent to that obtained with a search unit
method, the recommended couplant is clean, light-grade oil.
containing a single-crystal.
NOTE 4—Other coupling liquids may be employed for inspecting plate
5.2.1 The total effective area of the crystal or combination
provided their use does not adversely affect test results.
of crystals in the search unit used for initial scanning shall not
2 2 2
be less than 0.4 in. (2.6 cm ) nor greater than 3.0 in. (19.4
6. Personnel Requirements
cm ).
5.2.2 The effective diameter of the round search unit used to 6.1 The testing operator performing the ultrasonic examina-
evaluate discontinuity size shall not exceed 0.75 in. (19 mm). tion prescribed in this standard shall be qualified and certified
B548 − 03 (2017)
to at least a Level I—UltrasonicTesting in accordance with the 8.4.2 During the scan, note the occurrence of isolated
ASNT Recommended Practice SNT-TC-1A. discontinuity indications and monitor the amplitude of the first
back reflection by continuously observing theA-scan indicator
6.2 The required documentation supporting qualification
screen.
and certification of ultrasonic testing operators shall be estab-
NOTE 5—Auxiliary monitoring devices may be employed in the test
lished by the certifying agency and shall be available upon
system to enhance detection reliability during the scan.
request by the purchaser.
8.5 Scan Index—When the initial scan is completed, move
7. Condition of Plate
the search unit over a predetermined scan index distance in a
direction parallel to the predominant rolling direction of the
7.1 The entry and back surfaces of the inspected plate shall
plateandproceedwithasecondscanalongalineparalleltothe
be sufficiently clean, smooth, and flat to maintain a first back
initialscanningdirectionwhileobservingthetestpatternonthe
reflection amplitude greater than 50 % of the initial standard-
A-scan indicator screen. Calculate the scan index distance as
ization amplitude while scanning an area in the plate that does
follows:
not contain significant isolated ultrasonic discontinuities.
Scan index distance ~in.!, S 5 0.810.7D (1)
i s
7.2 The inspected plate shall be at room temperature during
Scan index distance mm , S 5 2010.7D (2)
~ !
i s
the test.
where:
8. Procedure
D = actual crystal diameter.
s
8.1 Preferred Method—The ultrasonic test may be per-
8.5.1 Continue the inspection by constantly observing the
formedbyeithertheliquidcolumncoupling,thedirectcontact, test pattern on the A-scan indicator while successively scan-
or the immersion methods. However, the immersion method is ning the plate at a constant scanning rate in a direction
preferred. perpendicular to the predominant rolling direction of the plate
and indexing the search unit through the index distance
8.1.1 Maintain the couplant distance so that the second
calculated in 8.5.
couplant reflection is to the right of the first back reflection on
8.5.2 Duringtheinspectionprocedure,checkthetestsystem
the instrument’s A-scan display. The couplant path shall not
sensitivity standardization periodically by noting the amplitude
vary more than 6 ⁄4 in. (6.4 mm) during calibration, initial
of the first back reflection when the search unit is repositioned
scanning, and discontinuity evaluation.
over the reference area of the plate and by adjusting the
8.2 Test Frequency—When using any of the three methods
instrument gain control as required to maintain the sensitivity
listed in 8.1, the recommended test frequency is 5.0 MHz.
standardization specified previously in 8.3.
Other test frequencies between 2.0 MHz and 10.0 MHz may be
8.6 Scanning Rate—When the screen pattern on the A-scan
employed when necessary to minimize possible adverse effects
indicator is monitored visually by the test operator during the
of plate thickness, microstructure, and test system characteris-
inspection, the scanning rate shall not be greater than 12 in./s
tics upon test results and thereby maintain a clean, easily
(305 mm/s).
interpreted A-scan screen pattern throughout the inspection.
NOTE 6—Scanning rates greater than 12 in./s (305 mm/s) may be
8.3 Sensitivity Standardization—Standardize the sensitivity
employed if auxiliary monitor
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