1、Designation: A 577/A 577M 90 (Reapproved 2007)Standard Specification forUltrasonic Angle-Beam Examination of Steel Plates1This standard is issued under the fixed designation A 577/A 577M; the number immediately following the designation indicates the yearof original adoption or, in the case of revis
2、ion, 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. Scope1.1 This specification2covers an ultrasonic angle-beamprocedure and acceptance standards for the detecti
3、on of inter-nal discontinuities not laminar in nature and of surface imper-fections in a steel plate. This specification is intended for useonly as a supplement to specifications which provide straight-beam ultrasonic examination.NOTE 1An internal discontinuity that is laminar in nature is onewhose
4、principal plane is parallel to the principal plane of the plate.1.2 Individuals performing examinations in accordance withthis specification shall be qualified and certified in accordancewith the requirements of the latest edition of ASNT SNT-TC-1A or an equivalent accepted standard. An equivalentst
5、andard is one which covers the qualification and certificationof ultrasonic nondestructive examination candidates and whichis acceptable to the purchaser.1.3 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. Within the text, theSI units are shown in b
6、rackets. The values stated in eachsystem are not exact equivalents; therefore, each system mustbe used independently of the other. Combining values from thetwo systems may result in nonconformance with the specifi-cation.2. Referenced Documents2.1 ASNT Standards:3SNT-TC-1A Recommended Practice for P
7、ersonnel Qualifi-cation and Certification in Nondestructive Testing3. Ordering Information3.1 The inquiry and order shall indicate any additions to theprovisions of this specification as prescribed in 11.1.4. Examination Conditions4.1 The examination shall be conducted in an area free ofoperations t
8、hat interfere with proper performance of theexamination.4.2 The surface of the plate shall be conditioned as neces-sary to provide a clear, easily interpreted trace pattern on thescreen. Any specified identification which is removed toachieve proper surface smoothness shall be restored.5. Apparatus5
9、.1 The amplitude linearity shall be checked by positioningthe transducer over the depth resolution notch in the IIW orsimilar block so that the signal from the notch is approximately30 % of the screen height, and the signal from one of the backsurfaces is approximately 60 % of the screen height (two
10、 timesthe height of the signal from the notch). A curve is then plottedshowing the deviations from the above established 2:1 ratiothat occurs as the amplitude of the signal from the notch israised in increments of one scale division until the backreflection signal reaches full scale, and then is low
11、ered inincrements of one scale division until the notch signal reachesone scale division. At each increment the ratio of the twosignals is determined. The ratios are plotted on the graph at theposition corresponding to the larger signal. Between the limitsof 20 % and 80 % of the screen height the ra
12、tio shall be within10 % of 2:1. Instrument settings used during inspection shallnot cause variation outside the 10 % limits established above.5.2 The search unit shall be a 45-deg (in steel) angle-beamtype with active transducer length and width dimensions of aminimum of12 in. 12.5 mm and a maximum
13、of 1 in. 25mm. Search units of other sizes and angles may be used foradditional exploration and evaluation.6. Examination Frequency6.1 The ultrasonic frequency selected for the examinationshall be the highest frequency that permits detection of the1This specification is under the jurisdiction of AST
14、M Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.11 on Steel Plates for Boilers and Pressure Vessels.Current edition approved March 1, 2007. Published March 2007. Originallyapproved in 1967. Last previous edition approved in 2001 as A 57
15、7/A 577M 90 (2001).2For ASME Boiler and Pressure Vessel Code applications, see related Specifi-cation SA-577/SA-577M in Section II of that Code. Available from AmericanSociety of Mechanical Engineers (ASME), ASME International Headquarters,Three Park Ave., New York, NY 10016-5990, http:/www.asme.org
16、.3Available fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.required calibration notch, such that
17、the amplitude of theindication yields a signal-to-noise ratio of at least 3:1.7. Calibration Reflector7.1 A calibration notch, the geometry of which has beenagreed upon by the purchaser and the manufacturer, with adepth of 3 % of the plate thickness, shall be used to calibratethe ultrasonic examinat
18、ion. The notch shall be at least 1 in. 25mm long.7.2 Insert the notch or notches on the surface of the plate sothat they are perpendicular to the long axis at a distance of 2 in.50 mm or more from the short edge of the plate. Locate thenotch not less than 2 in. 50 mm from the long edges of theplate.
19、7.3 When the notch cannot be inserted in the plate to betested, it may be placed in a calibration plate of ultrasonicallysimilar material. The calibration plate will be consideredultrasonically similar if the height of the first back reflectionthrough it is within 25 % of that through the plate to b
20、e testedat the same instrument calibration. The calibration platethickness shall be within 1 in. 25 mm of the thickness ofplates to be tested, for plates of 2 in. 50 mm thickness andgreater and within 10 % of plates whose thickness is less than2 in. 50 mm.7.4 For plate thicknesses greater than 2 in.
21、 50 mm, inserta second calibration notch as described in 7.2, on the oppositeside of the plate.8. Calibration Procedure8.1 Plate 2 in. 50 mm and Under in Thickness:8.1.1 Place the search unit on the notched surface of theplate with the sound beam directed at the broad side of thenotch and position t
22、o obtain maximum amplitude from the firstvee-path indication which is clearly resolved from the initialpulse. Adjust the instrument gain so that this reflection ampli-tude is at least 50 but not more than 75 % of full screen height.Record the location and amplitude of this indication on thescreen.8.
23、1.2 Move the search unit away from the notch until thesecond vee-path indication is obtained. Position the search unitfor maximum amplitude and record the indication amplitude.Draw a line between the peaks from the two successive notchindications on the screen. This line is the distance amplitudecur
24、ve (DAC) for this material and shall be a 100 % referenceline for reporting indication amplitudes.8.2 Plate Over 2 to 6 in. 50 to 150 mm Inclusive inThickness:8.2.1 Place the search unit on the test surface aimed at thebroad side of the notch on the opposite surface of the plate.Position the search
25、unit to obtain a maximum one-half vee-pathindication amplitude. Adjust the instrument gain so that thisamplitude is at least 50 % but not more than 80 % of full screenheight. Record the location and amplitude on the screen.Without adjusting the instrument settings, repeat this procedurefor the 112 v
26、ee-path indication.8.2.2 Without adjusting the instrument settings, repositionthe search unit to obtain a maximum full vee-path indicationfrom the notch on the test surface. Record the location andamplitude on the screen.8.2.3 Draw a line on the screen connecting the pointsestablished in 8.2.1 and 8
27、.2.2. This curve shall be a DAC forreporting indication amplitudes.8.3 Plate over 6 in. 150 mm in Thickness:8.3.1 Place the search unit on the test surface aimed at thebroad side of the notch on the opposite surface of the plate.Position the search unit to obtain a maximum one-half vee-pathindicatio
28、n amplitude. Adjust the instrument gain so that thisamplitude is at least 50 % but not more than 80 % of full screenheight. Record the location and amplitude on the screen.8.3.2 Without adjusting the instrument settings, repositionthe search unit to obtain a maximum full vee-path indicationfrom the
29、notch on the test surface. Record the location andamplitude on the screen.8.3.3 Draw a line on the screen connecting the pointsestablished in 8.3.1 and 8.3.2. This line shall be a DAC forreporting indication amplitudes.9. Examination Procedure9.1 Scan one major surface of the plate on grid linesperp
30、endicular and parallel to the major rolling direction. Gridlines shall be on 9-in. 225-mm centers. Use a suitablecouplant such as water, oil, or glycerin. Scan by placing thesearch unit near one edge with the ultrasonic beam directedtoward the same edge and move the search unit along the gridline in
31、 a direction perpendicular to the edge to a location twoplate thicknesses beyond the plate center. Repeat this scanningprocedure on all grid lines from each of the four edges.9.2 Measure grid lines from the center or one corner of theplate.9.3 Position the search unit to obtain a maximum indicationa
32、mplitude from each observed discontinuity.9.4 For each discontinuity indication that equals or exceedsthe DAC, record the location and length, and the amplitude tothe nearest 25 %. No indication with an amplitude less than theDAC shall be recorded.9.5 At each recorded discontinuity location, conduct
33、 a100 % examination of the mass under a 9-in. 225-mm squarewhich has the recorded discontinuity position at its center.Conduct the examination in directions perpendicular andparallel to the major rolling direction.10. Acceptance Standard10.1 Any discontinuity indication that equals or exceeds theDAC
34、 shall be considered unacceptable unless additional ex-ploration by the longitudinal method indicates it is laminar innature.11. Report11.1 Unless otherwise agreed upon between the purchaserand manufacturer, the manufacturer shall report the followingdata:11.1.1 Plate identity including pin-pointed
35、recordable indi-cation locations, lengths, and amplitudes.11.1.2 Examination parameters, including: couplant; searchunit type, angle, frequency, and size; instrument make, model,and serial number; and calibration plate description.11.1.3 Date of examination and name of operator.A 577/A 577M 90 (2007
36、)212. Inspection12.1 The purchasers representative shall have access, at alltimes while work on the contract of the purchaser is beingperformed, to all parts of the manufacturers works thatconcern the ultrasonic examination of the material ordered.The manufacturer shall afford the representative all
37、 reasonablefacilities to satisfy him that the material is being furnished inaccordance with this specification. All examinations and veri-fications shall be so conducted as not to interfere unnecessarilywith the manufacturers operations.13. Rehearing13.1 The manufacturer reserves the right to discus
38、s unac-ceptable ultrasonically examined plate with the purchaser withthe object of possible repair of the ultrasonically indicateddiscontinuity before rejection of the plate.14. Marking14.1 Plates accepted in accordance with this specificationshall be identified by metal stamping or stencilling “UTA
39、 577”in one corner of the plate, at a location within 6 in. 150 mmof the heat number.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of th
40、e validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. You
41、r comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments
42、 have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).A 577/A 577M 90 (2007)3
