1、Designation: E2660 10Standard Digital Reference Images forInvestment Steel Castings for Aerospace Applications1This standard is issued under the fixed designation E2660; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 The digital reference images provided in the adjunct tothis standard illustrate various types and degrees of disconti-n
3、uities occurring in thin-wall steel investment castings.2Use ofthis standard for the specification or grading of castingsrequires procurement of the adjunct digital reference imageswhich illustrate the discontinuity types and severity levels.They are intended to provide the following:1.1.1 A guide e
4、nabling recognition of thin-wall steel castingdiscontinuities and their differentiation both as to type anddegree through digital radiographic examination.1.1.2 Example digital radiographic illustrations of disconti-nuities and a nomenclature for reference in acceptance stan-dards, specifications an
5、d drawings.1.2 Two illustration categories are covered as follows:1.2.1 GradedSix common discontinuity types each illus-trated in eight degrees of progressively increasing severity.1.2.2 UngradedTwelve single illustrations of additionaldiscontinuity types and of patterns and imperfections notgeneral
6、ly regarded as discontinuities.1.3 The reference radiographs were developed for castingsections up to 1 in. (25.4 mm) in thickness.1.4 All areas of this standard may be open to agreementbetween the cognizant engineering organization and the sup-plier, or specific direction from the cognizant enginee
7、ringorganization. These items should be addressed in the purchaseorder or the contract.NOTE 1The set of digital reference images consists of 16 digital files,software to load the desired format and specific instructions on the loadingprocess. The 16 reference images illustrate eight grades of severi
8、ty in sixcommon discontinuity types and twelve ungraded discontinuities andcontain an image of a step wedge and two duplex-wire gauges. Refer toPractice E2002 for wire pair details.1.5 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematic
9、alconversions to SI units that are provided for information onlyand are not considered standard.1.6 These digital reference images are not intended toillustrate the types or degrees of discontinuities when perform-ing film radiography. If performing film radiography of thin-wall investment castings,
10、 refer to Reference RadiographsE192.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limi
11、tations prior to use.1.8 Only licensed copies of the software and images shall beutilized for production inspection. A copy of the ASTM/Userlicense agreement shall be kept on file for audit purposes.2. Referenced Documents2.1 ASTM Standards:3E94 Guide for Radiographic ExaminationE192 Reference Radio
12、graphs of Investment Steel Castingsfor Aerospace ApplicationsE1025 Practice for Design, Manufacture, and MaterialGrouping Classification of Hole-Type Image Quality Indi-cators (IQI) Used for RadiologyE1316 Terminology for Nondestructive ExaminationsE1320 Reference Radiographs for Titanium CastingsE2
13、002 Practice for Determining Total Image Unsharpnessin RadiologyE2597 Practice for Manufacturing Characterization of Digi-tal Detector Arrays2.2 SMPTE Practice:4RP133 SMPTE Recommended Practice Specifications forMedical Diagnostic Imaging test Pattern for TelevisionMonitors and Hard-Copy Recording C
14、ameras1This standard is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.02 onReference Radiological Images.Current edition approved Jan. 1, 2010. Published February 2010.2The digital reference images are considered to be ap
15、plicable to all thin-wallsteel castings, requiring close tolerances. They may also be used for nickel-base andcobalt-base cast alloys. Castings for which these images are applicable generallyinclude those made by the lost wax, frozen mercury, ceramicast or shell moldprocesses.3For referenced ASTM st
16、andards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from Society of Motion Picture and Television Engineers, 3 BarkerAvenue,
17、White Plains, NY 10601; or www.smpte.org/smpte_store/1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.3 ASTM Adjuncts:Digital Reference Images of Investment Steel Castings forAerospace Applications53. Terminology3.1 DefinitionsDefin
18、itions of terms used in this standardmay be found in Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 The terms relating to discontinuities used in thesedigital reference images are described based upon radiographicappearance when viewed in the negative polarity such that t
19、heimages appear in the same sense as they would when viewedon X-ray film. If images are viewed in the positive polarity, theterms lighter and darker will need to be reversed.3.2.2 aliasingartifacts that appear in an image when thespatial frequency of the input is higher than the output iscapable of
20、reproducing. This will often appear as jagged orstepped sections in a line or as moir patterns.3.2.3 contrast normalizationthe adjustment of contrastbetween the production image and the reference image thatmakes the change in digital driving level versus change inthickness equal for both images.3.2.
21、4 DDLdigital driving level also known as monitorpixel value.3.2.5 system resolutionthe detector-measured resolutiondivided by the geometric magnification.3.2.6 Gas3.2.6.1 gas holesround or elongated, smooth edged darkspots, occurring individually, in clusters, or distributed ran-domly throughout the
22、 casting.3.2.7 Shrinkage3.2.7.1 shrinkage cavityan area with distinct jaggedboundaries.3.2.7.2 shrinkage, spongean area, lacy in texture, with avery diffuse outline.3.2.7.3 shrinkage, dendritica distribution of very finelines or small elongated cavities that may vary in darkness andare usually uncon
23、nected.3.2.7.4 shrinkage, filamentaryusually a continuous struc-ture of connected lines or branches of variable length, widthand darkness, or occasionally, a network.3.2.8 foreign material less denseirregularly shaped indi-cations darker than the adjacent material, but lighter than gasholes of simil
24、ar magnitude.3.2.9 foreign material more denseirregularly shaped indi-cations lighter than the adjacent material.3.2.10 Discrete Discontinuities3.2.10.1 hot tearsragged dark lines of variable width andnumerous branches. They have no definite lines of continuityand may exist in groups. They may origi
25、nate internally or at thesurface.3.2.10.2 cold cracksstraight or jagged lines usually con-tinuous throughout their length. Cold cracks generally appearsingly. They start at the surface.3.2.10.3 cold shuta distinct dark line or band of variablelength and definite smooth outline.3.2.10.4 misrunspromin
26、ent dark areas of variable dimen-sions with a definite smooth outline.3.2.10.5 core shifta variation in wall thickness.3.2.11 defective moldis illustrated by such common de-fects as mold crack, mold ridge, rattail, scab, and fin. Theseconditions appear as areas or lines of different darkness thanthe
27、 adjacent material. Illustrations of the defect include:3.2.11.1 mold buckle, positivea lightened irregularlyshaped area lightest near the center and gradually increasing indarkness away from the center.3.2.11.2 mold buckle, negativea darkened irregularlyshaped area darkest near the center and gradu
28、ally gettinglighter away from the center.4. Significance and Use64.1 These digital reference images are intended for refer-ence only, but are designed such that acceptance standards,which may be developed for particular requirements, can bespecified in terms of these digital reference images. Theill
29、ustrations are digital images of castings that were producedunder conditions designed to develop the discontinuities.4.1.1 Graded Discontinuities:4.1.1.1 Gas holes, sponge shrinkage, dendritic shrinkage,less dense foreign material(1) The images of the18-in (3.2-mm) castings are intendedto be used in
30、 the thickness range up to and including14-in(6.3-mm). The images of the38-in (9.5-mm) castings areintended to be used in the thickness range of over14-in(6.4-mm), up to and including12-in (12.7-mm). The images ofthe34-in (19.1-mm) castings are intended to be used in thethickness range of over12-in
31、(12.7-mm), up to and including1-in. (25.4-mm).4.1.1.2 Cavity Shrinkage, Filamentary Shrinkage:(1) The images of the34-in (19.1-mm) castings areintended to be used in the thickness range up to and including1-in. (25.4-mm).4.1.2 Ungraded Discontinuities:4.1.2.1 The images of the38-in (9.5-mm) castings
32、 areintended to be used in the thickness range up to and including1-in. (25.4-mm).4.2 Image DeteriorationMany conditions can affect theappearance and functionality of digital reference images. Forexample, electrical interference, hardware incompatibilities,and corrupted files and drivers may affect
33、their appearance. ThePractice E2002 line pair gauges located in each digital refer-ence image can be used as an aid to detect image deteriorationby comparing the measured resolution using the gauges to theresolution stated on the digital reference image. Do not use thedigital reference images if the
34、ir appearance has been adverselyaffected such that the interpretation and use of the images couldbe influenced.5Available from ASTM International Headquarters. Order Adjunct No.RRE2660.6A study was performed that compared film to digital modalities for theclassification of aluminum casting discontin
35、uities. Results of this study are availablefrom ASTM as RR:E07-1004. A subsequent study was performed that comparedfilm to digital modalities for the classification of titanium and steel castingdiscontinuities. Results of this study are available from ASTM as RR:E07-1006.E2660 1024.3 Agreement shoul
36、d be reached between cognizant engi-neering organization and the supplier that the system used bythe supplier is capable of detecting and classifying the requireddiscontinuities.5. Basis of Application5.1 The digital reference images may be applied as accep-tance standards tailored to the end use of
37、 the product. Appli-cation of these digital reference images as acceptance standardsshould be based on the intended use of the product and thefollowing considerations (see Note 2).5.1.1 An area of like size to that of the digital referenceimage shall be the unit areas by which the production digital
38、image is evaluated, and any such area shall meet the require-ments as defined for acceptability.5.1.2 Any combination or subset of these digital referenceimages may be used as is relevant to the particular application.Different grades or acceptance limits may be specified for eachdiscontinuity type.
39、 Furthermore, different grades may be speci-fied for different regions, or zones of a component.5.1.3 Special considerations may be required where morethan one discontinuity type is present in the same area. Anymodifications to the acceptance criteria required on the basis ofmultiple discontinuity t
40、ypes must be specified.5.1.4 Production digital images containing porosity, gas, orinclusions may be rated by the overall condition with regard tosize, number, and distribution. These factors should be consid-ered in balance.5.1.5 As a minimum, the acceptance criteria should containinformation addre
41、ssing: zoning of the part (if applicable), theacceptance severity level for each discontinuity type, and thespecified area to which the digital reference images are to beapplied.5.1.6 Where the reference images provide only an ungradedillustration of a discontinuity, an acceptance level may bespecif
42、ied by referencing a maximum discontinuity size, or apercentage of the discontinuity size illustrated.NOTE 2Caution should be exercised in specifying the acceptancecriteria to be met in a casting. Casting design coupled with foundrypractice should be considered. It is advisable to consult with thema
43、nufacturer/foundry before establishing the acceptance criteria to ensurethe desired quality level can be achieved.6. Procedure for Evaluation6.1 Select the appropriate Digital Reference Image.6.2 Apply any necessary adjustments to the contrast of thereference image. Contrast adjustment may be conduc
44、ted usinga process of contrast normalization between the productionimage and the reference image, or by an alternative processapproved by the cognizant engineering organization.6.3 If contrast normalization is used, perform the contrastnormalization (window width normalization) between the pro-ducti
45、on image and the reference image as required by 9.5.6.3.1 Once the contrast normalization has been performed,contrast (window width) shall not be altered in either imagewithout re-performing contrast normalization prior to productevaluation. (See 9.5.)7. Description7.1 The digital reference images l
46、isted in Table 1 illustrateeach type of graded discontinuity in eight grades. Althougheight grades of each discontinuity are shown, a numericallysmaller graded set of discontinuities based on these digitalreference images could be used for acceptance standards.7Theungraded illustrations have been in
47、cluded to establish theappearance of the digital image indications they represent inthin-wall investment castings.7.2 The alloys used to reproduce the various discontinuitiesare listed in Table 2.7.3 The step wedges shown in the digital reference imagesare made of 8630 steel with the step thicknesse
48、s listed in Table3.8. Digital Image Installation Procedure8.1 Follow the instructions provided with the digital refer-ence images to load the reference image software.8.2 The software files will be saved to a default locationduring installation unless instructed otherwise during theloading process.7
49、Each grade of a given discontinuity type is contained in an individualapproximate 2 by 234-in. (51 by 70-mm) machined cast block. These blocks wereinserted in steel keeper plates with radiographic characteristics similar to the castblocks. The assembled plates were then radiographed and digitally reproduced toobtain the various gradations shown. The image content utilized in the referenceimages for each cast block is approximately 1.81 by 2.5-in. (46 by 63.5-mm).TABLE 1 Digital Reference Images for Investment Steel Castingsfor Aerospace Applications
