STANDARD SPECIFICATION FOR STRAIGHT-BEAM ULTRASONIC EXAMINATION OF PLAIN AND CLAD STEEL PLATES FOR SPECIAL APPLICATIONS
SA-578/SA-578M
[Identical with ASTM Specification A578/A578M-96(R2001)]
1.Scope
1.1This specification covers the procedure and accept-ance standards for straight-beam,pul-echo,ultrasonic examination of rolled carbon and alloy plain and clad steel plates,3⁄8in.[10mm]in thickness and over,for special applications.The method will detect internal discontinu-ities parallel to the rolled surfaces.Three levels of accept-ance standards are provided.Supplementary requirements are provided for examination of clad plate and for alterna-tive procedures.
1.2Individuals performing examinations in accordance with this specification shall be qualified and certi
fied 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 qualifica-tion and certification of ultrasonic nondestructive examina-tion candidates and which is acceptable to the purchar. 1.3The values stated in either inch-pound units or SI units are to be regarded parately 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 ud independently of the other.Combining values from the two systems may result in nonconformance with the specification.
1.4This standard does not purport to address all of the safety concerns,if any,associated with its u.It is the responsibility of the ur of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to u.
2.Referenced Documents
2.1ASTM Standards:
A263Specification for Corrosion-Resisting Chromium Steel–Clad Plate,Sheet,and Strip
woot365A264Specification for Stainless Chromium-Nickel Steel–Clad Plate,Sheet,and Strip
A265Specification for Nickel and Nickel-Ba Alloy–Clad Steel Plate
2.2ANSI Standard:
B46.1Surface Texture
2.3ASNT Standard:
SNT-TC-1A Recommended Practice for Personnel Quali-
fication and Certification in Nondestructive Testing
3.Ordering Information
3.1The inquiry and order shall indicate the following:
3.1.1Acceptance level requirements(Sections7,8,
and9).Acceptance Level B shall apply unless otherwi agreed to by purchar and manufacturer.
3.1.2Any additions to the provisions of this specifi-cation as prescribed in5.2,12.1,and Section13.
3.1.3Supplementary requirements,if any.
4.Apparatus
4.1The amplitude linearity shall be checked by posi-tioning the transducer over the depth resolution notch in
the IIW or similar block so that the signal from the notch
is approximately30%of the screen height,and the signal from one of the back surfaces is approximately60%of
the screen height(two times the height of the signal from
the notch).A curve is then plotted showing the deviations from the above established2:1ratio that occurs as the amplitude of the signal from the notch is raid in incre-ments of one scale division until the back reflection signal reaches full scale,and then is lowered in increments of
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one scale division until the notch signal reaches one scale division.At each increment the ratio of the two signals is determined.The ratios are plotted on the graph at the position corresponding to the larger signal.Between the limits of20%and80%of the screen height,the ratio shall
be within10%of2:1.Instrument ttings ud during inspection shall not cau variation outside the10%limits established above.
4.2The transducer shall be1or11⁄8in.[25or30mm]
in diameter or1in.[25mm]square.
4.3Other arch units may be ud for evaluating and pinpointing indications.
5.Procedure
5.1Perform the inspection in an area free of operations that interfere with proper performance of the test.
5.2Unless otherwi specified,make the ultrasonic examination on either major surface of the plate.
5.3The plate surface shall be sufficiently clean and smooth to maintain afirst reflection from the opposite side
of the plate at least50%of full scale during scanning. This may involve suitable means of scale removal at the manufacturer’s option.Condition local rough surfaces by grinding.Restore any specified identification which is removed when grinding to achieve proper surface smoothness.bestfriend
5.4Perform the test by one of the following methods: direct contact,immersion,or liquid column coupling.U
a suitable couplant such as water,soluble oil,or glycerin.
As a result of the test by this method,the surface of plates may be expected to have a residue of oil or rust,or both. 5.5A nominal test frequency of21⁄4MHz is recom-mended.When testing plates less than3⁄4in.[20mm]thick,
a frequency of5MHz may be necessary.Thickness,grain size or microstructure of the material and nature of the equipment or method may require a higher or lower test frequency.U the transducers at their rated frequency.A clean,easily interpreted trace pattern should be produced during the examination.
5.6Scanning:
5.6.1Scanning shall be along continuous perpendic-ular grid lines on nominal9-in.[225-mm]centers,or at the option of the manufacturer,shall be along continuous parallel paths,transver to the major plate axis,on nominal
4-in.[100-mm]centers,or shall be along continuous paral-
lel paths parallel to the major plate axis,on3-in.[75-mm]
or smaller centers.Measure the lines from the center or one corner of the plate with an additional path within2in. [50mm]of all edges of the plate on the arching surface.
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绯闻少女第二季5.6.2Conduct the general scanning with an instru-ment adjustment that will produce afirst reflection from the opposite side of a sound area of the plate from50% to90%of full scale.Minor nsitivity adjustments may be made to accommodate for surface roughness.
5.6.3When a discontinuity condition is obrved during general scanning,adjust the instrument to pro
duce afirst reflection from the opposite side of a sound area of the plate of75±5%of full scale.Maintain this instrument tting during evaluation of the discontinuity condition.
6.Recording
6.1Record all discontinuities causing complete loss of back reflection.
6.2For plates3⁄4in.[20mm]thick and over,record all indications with amplitudes equal to or greater than50% of the initial back reflection and accompanied by a50% loss of back reflection.
NOTE2—Indications occurring midway between the initial pul and thefirst back reflection may cau a cond reflection at the location of thefirst back reflection.When this condition is obrved it shall be investigated additionally by u of multiple back reflections.
6.3Where grid scanning is performed and recordable conditions as in6.1and6.2are detected along a given grid line,the entire surface area of the squares adjacent to this indication shall be scanned.Where parallel path scanning is performed and recordable conditions as in6.1 and6.2are detected,the entire surface area of a9by9-in. [225by225-mm]square centered on this indication shall be scanned.The true boundaries where the conditions exist shall be established in either method
by the following technique:Move the transducer away from the center of the discontinuity until the height of the back reflection and discontinuity indications are equal.Mark the plate at a point equivalent to the center of the transducer.Repeat the operation to establish the boundary.
tamia7.Acceptance Standard—Level A
7.1Any area where one or more discontinuities produce
a continuous total loss of back reflection accompanied by continuous indications on the same plane that cannot be encompasd within a circle who diameter is3in. [75mm]or1⁄2of the plate thickness,whichever is greater, is unacceptable.
8.Acceptance Standards—Level B
8.1Any area where one or more discontinuities produce
a continuous total loss of back reflection accompanied by continuous indications on the same plane that cannot be encompasd within a circle who diameter is3in.
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[75mm]or1⁄2of the plate thickness,whichever is greater,
is unacceptable.
8.2In addition,two or more discontinuities smaller than described in8.1shall be unacceptable unless parated
by a minimum distance equal to the greatest diameter of the larger discontinuity or unless they may be collectively encompasd by the circle described in8.1.
9.Acceptance Standard—Level C
9.1Any area where one or more discontinuities produce
a continuous total loss of back reflection accompanied by continuous indications on the same plane that cannot be encompasd within a1-in.[25-mm]diameter circle is unacceptable.
10.Rehearing
10.1The manufacturer rerves the right to discuss rejectable ultrasonically tested plate with the pur
char with the object of possible repair of the ultrasonically indi-cated defect before rejection of the plate.
11.Inspection
11.1The inspector reprenting the purchar shall have access at all times,while work on the contract of the purchar is being performed,to all parts of the manufactur-er’s works that concern the ultrasonic testing of the material ordered.The manufacturer shall afford the inspector all reasonable facilities to satisfy him that the material is being furnished in accordance with this specification.All tests and inspections shall be made at the place of manufacture
367prior to shipment,unless otherwi specified,and shall be conducted without interfering unnecessarily with the manufacturer’s operations.
12.Marking
12.1Plates accepted according to this specification shall be identified by stenciling(stamping)“UT A578—A”on one corner for Level A,“UT A578—B”for Level B,and“UT A578—C”for Level C.The supplement number shall be added for each supplementary requirement ordered.
13.Report
13.1Unless otherwi agreed to by the purchar and the manufacturer,the manufacturer shall report the follow-ing data:
13.1.1All recordable indications listed in Section6 on a sketch of the plate with sufficient data to relate the geometry and identity of the sketch to tho of the plate.
13.1.2Test parameters including:Make and model of instrument,test frequency,surface condition,transducer (type and frequency),and couplant.
13.1.3Date of test.
14.Keywords
14.1nondestructive testing;pressure containing parts; pressure vesl steels;steel plate for pressure vesl appli-cations;steel plates;ultrasonic examinations
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SUPPLEMENTARY REQUIREMENTS
The supplementary requirements shall apply only when individually specified by the purchar.When details of the requirements are not covered herein,they are subject to agreement between the manufacturer and the purchar.
S1.Scanning
S1.1Scanning shall be continuous over100%of the plate surface.
S2.Acceptance Standard
S2.1Any recordable condition listed in Section6that (1)is continuous,(2)is on the same plane(within5%of the plate thickness),and(3)cannot be encompasd by a
3-in.[75-mm]diameter circle,is unacceptable.Two or more recordable conditions(e Section5),that(1)are
on the same plane(within5%of plate thickness),(2) individually can be encompasd by a3-in.[75-mm]diam-eter circle,(3)are parated from each other by a distance less than the greatest dimension of the smaller indication, and(4)collectively cannot be encompasd by a3-in. [75-mm]diameter circle,are unacceptable.
S2.2An acceptance level more restrictive than Section
7or8shall be ud by agreement between the manufacturer and purchar.
S3.Procedure
S3.1The manufacturer shall provide a written proce-dure in accordance with this specification.
S4.Certification
S4.1The manufacturer shall provide a written certifi-cation of the ultrasonic test operator’s qualifications.
S5.Surface Finish
S5.1The surfacefinish of the plate shall be conditioned
荷兰语to a maximum125in.[3m]AA(e ANSI B46.1) prior to test.
S6.Examination of Integrally Bonded Clad Plate, Acceptance Level S6
S6.1Examine the plate from the clad surface using procedures and techniques in accordance with this specifi-cation.
S6.2Inspect the backing steel to Level B,or,if specifi-cally requested by customer,to Level A or Level C.
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S6.3The cladding shall be interpreted to be unbonded when there is complete loss of back reflection accompanied by an echo indication from the plane of the interface of the clad and backing steel.
2012年江苏高考英语S6.4Unless otherwi specified,indications of unbond determined in accordance with S6.3that cannot be encom-pasd within a3-in.[75-mm]diameter circle shall be weld repaired subject to the requirements and limitations for the repair of defects in cladding of the appropriate material specification.
S6.5This supplementary requirement is applicable to Specifications A263,A264,and A265.
S7.Examination of Integrally Bonded Clad Plate, Acceptance Level S7
S7.1The plate shall be examined from the clad surface using procedures and techniques according to this specifi-cation except100%surface arch is mandatory.
S7.2Inspect the backing steel to Level B,or,if specifi-cally requested by customer,to Level A or Level C.
S7.3The cladding shall be interpreted to be unbonded when there is complete loss of back reflection accompanied by an echo indication from the plane of the interface of the clad and backing steel.
S7.4Unless otherwi specified,indications of unbond determined in accordance with S7.3that cannot be encom-pasd within a1-in.[25-mm]diameter circle shall be weld repaired subject to the requirements and limitations for the repair of defects in cladding of the appropriate material specification.Additionally,prior approval must be obtained if the weld repaired surface exceeds1.5%of the cladding surface.
S7.5This supplementary requirement is applicable to Specifications A263,A264,and A265.
S8.Ultrasonic Examination Using Flat Bottom Hole Calibration(for Plates4in.[100mm]Thick
and Greater)
S8.1U the following calibration and recording proce-dures in place of5.6.2,5.6.3,and Section6.
S8.2The transducer shall be in accordance with4.2.
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TABLE S8.1
CALIBRATION HOLE DIAMETER AS A FUNCTION OF PLATE THICKNESS(S8)
Plate Thickness,in.[mm]4–6[100–150]>6–9[>150–225]>9–12[>225–300]>12–20[>300–500] Hole Diameter,in.[mm]5⁄8[16]3⁄4[19]7⁄8[22]11⁄8[29]
S8.3Reference Reflectors—The T/4,T/2,and3T/4 deepflat bottom holes shall be ud to calibrate the equip-ment.Theflat bottom hole diameter shall be in accordance with Table S8.1.The holes may be drilled in the plate to
be examined if they can be located without interfering with the u of the plate,in a prolongation of the plate to be examined,or in a reference block of the same nominal composition,and thermal treatment as the plate to be exam-ined.The surface of the reference block shall be no better
to the unaided eye than the plate surface to be examined. The reference block shall be of the same nominal thickness (within75to125%or1in.[25mm]of the examined plate, whichever is less)and shall have acoustical properties simi-
lar to the examined plate.Acoustical similarity is presumed when,without a change in instrument tting,comparison
of the back reflection signals between the reference block and the examined plate shows a variation of25%or less.
S8.4Calibration Procedure:
S8.4.1Couple and position the arch unit for maxi-mum amplitudes from the reflectors at T/4,T/2,and3T/4. Set the instrument to produce a75±5%of full scale indication from the reflector giving the highest amplitude.
S8.4.2Without changing the instrument tting,cou-ple and position the arch unit over each of the holes and mark on the screen the maximum amplitude from each hole and each minimum remaining back reflection.
S8.4.3Mark on the screen half the vertical distance from the sweep line to each maximum amplitude hole mark.Connect the maximum amplitude hole marks and extend the line through the thickness for the100%DAC (distance–amplitude correction curve).Similarly connect and extend the half maximum amplitude marks for the 50%DAC.
S8.5Recording:
S8.5.1Record all areas where the remaining back
reflection is smaller than the highest of the minimum remaining back reflections found in S8.4.2.
变量英语S8.5.2Record all areas where indications exceed 50%DAC.
S8.5.3Where recordable conditions listed in S8.5.1 and S8.5.2are detected along a given grid line,continu-ously scan the entire surface area of the squares adjacent
我朋友的辣妈to the condition and record the boundaries or extent of each recordable condition.
S8.6Scanning shall be in accordance with5.6.
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S8.7The acceptance levels of Section7or8shall apply as specified by the purchar except that the recordable condition shall be as given in S8.5.
S9.Ultrasonic Examination of Electroslag Remelted (ESR)and Vacuum-Arc Remelted(VAR)
Plates,from1to16in.[25to400mm]in
Thickness,Using Flat-Bottom Hole Calibration
and Distance–Amplitude Corrections英国女王圣诞致辞
S9.1The material to be examined must have a surface finish of200in.[5m]as maximum for plates up to8 in.[200mm]thick,inclusive,and250in.[6m]as maximum for plates over8to16in.[200to400mm]thick. S9.2U the following procedures in place of5.6.1, 5.6.2,5.6.3,and Section6.
S9.3The transducer shall be in accordance with4.2. S9.4Reference Reflectors—The T/4,T/2,and3T/4 deepflat bottom holes shall be ud to calibrate the equip-ment.Theflat bottom hole diameter shall be in accordance with Table S9.1.Theflat bottoms of the holes shall be within1°of parallel to the examination surface.The holes may be drilled in the plate to be examined if they can be located without interfering with the u of the plate,in a prolongation of the plate to be examined,o
r in a reference block of the same nominal composition and thermal treat-ment as the plate to be examined.The surface of the refer-ence block shall be no better to the unaided eye than the plate surface to be examined.The reference block shall be of the same nominal thickness(within75to125%or1in. [25mm]of the examined plate,whichever is less)and shall have acoustical properties similar to the examined plate.Acoustical similarity is presumed when,without a change in instrument tting,comparison of the back reflection signals between the reference block and the examined plate shows a variation of25%or less.
S9.5Calibration Procedure:
S9.5.1Couple and position the arch unit for maxi-mum amplitudes from the reflectors at T/4,T/2,and3T/4. Set the instrument to produce a75±5%of full-scale indication from the reflector giving the highest amplitude.
S9.5.2Without changing the instrument tting,cou-ple and position the arch unit over each of the holes and mark on the screen the maximum amplitude from each of the holes.
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TABLE S9.1
CALIBRATION HOLE DIAMETER AS A FUNCTION OF PLATE THICKNESS(S9)
Plate Thickness,in.[mm]1–4[25–100]>4–8[>100–200]>8–12[>200–300]>12–16[>300–400] Hole Diameter,in.[mm]1⁄8[3]1⁄4[6]3⁄8[10]1⁄2[13]
S9.5.3Mark on the screen half the vertical distances from the sweep line to each maximum amplitude hole mark.Connect the maximum amplitude hole marks and extend the line through the thickness for the100%DAC (distance–amplitude correction curve).Similarly connect and extend the half maximum amplitude marks for the 50%DAC.
S9.6Scanning—Scanning shall cover100%of one major plate surface,with the arch unit being indexed between each pass such that there is at least15%overlap
of adjoining pass in order to assure adequate coverage
for locating discontinuities.
S9.7Recording—Record all areas where the back
reflection drops below the50%DAC.If the drop in back
370reflection is not accompanied by other indications on the screen,recondition the surface in the area and reexamine ultrasonically.If the back reflection is still below50% DAC,the loss may be due to the metallurgical structure of the material being examined.The material shall be held for metallurgical review by the purchar and manufac-turer.
S9.8Acceptance Standards—Any indication that exceeds the100%DAC shall be considered unacceptable. The manufacturer may rerve the right to discuss rejectable ultrasonically examined material with the pur-char,the object being the possible repair of the ultrasoni-cally indicated defect before rejection of the plate.
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