1、Designation: E2868 17Standard Digital Reference Images forSteel Castings up to 2 in. (50.8 mm) in Thickness1This standard is issued under the fixed designation E2868; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 These digital reference images illustrate variouscategories, types, and severity levels of discontinuities occur-ring in
3、steel castings that have section thicknesses up to 2 in.(50.8 mm). The digital reference images are an adjunct to thisstandard and must be purchased separately from ASTMInternational, if needed (see 2.3). Categories and severitylevels for each discontinuity type represented by these digitalreference
4、 images are described in 1.2.NOTE 1The basis of application for these reference images requires aprior purchaser supplier agreement of radiographic examination attributesand acceptance criteria as described in Sections 4, 6, and 7 of thisstandard.1.2 These digital reference images consist of three s
5、eparatevolumes (see Note 2) as follows: (I) medium voltage (nominal250-kV) X rays, (II) 1-MV X rays and Iridium-192 radiation,and (III) 2-MV to 4-MV X rays and Cobalt-60 radiation.Unless otherwise specified in a purchaser supplier agreement(see 1.1), each volume is for comparison only with productio
6、ndigital images produced with radiation energy levels within thethickness range covered by this standard. Each volume consistsof six categories of graded discontinuities of increasing sever-ity level and four categories of ungraded discontinuities.Reference images containing ungraded discontinuities
7、 areprovided as a guide for recognition of a specific castingdiscontinuity type where severity levels are not needed. Thefollowing is a list of discontinuity categories, types, andseverity levels for the adjunct digital reference images of thisstandard:1.2.1 Category A Gas porosity; severity levels
8、1 through5.1.2.2 Category B Sand and slag inclusions; severity levels1 through 5.1.2.3 Category C Shrinkage; 4 types:1.2.3.1 Calinear shrinkage Severity levels 1 through 5.1.2.3.2 Cbfeathery shrinkage Severity levels 1 through 5.1.2.3.3 Ccsponge shrinkage Severity levels 1 through 5.1.2.3.4 Cdcombin
9、ations of linear, feathery, and spongeshrinkage Severity levels 1 through 5.1.2.4 Category DCrack; 1 illustration.1.2.5 Category EHot Tear; 1 illustration.1.2.6 Category FInsert; 1 illustration.1.2.7 Category GMottling; 1 illustration. (See Note 3.)NOTE 2The digital reference images consist of the f
10、ollowing:Volume I: Medium Voltage (nominal 250-kVp) X-Ray Reference Images Set of 34 illustrations.Volume II: 1-MV X Rays and Iridium-192 Reference Images Set of 34illustrations.Volume III: 2-MV to 4-MV X Rays and Cobalt-60 Reference Images Setof 34 illustrations.NOTE 3Although Category G Mottling i
11、s listed for all threevolumes, the appearance of mottling is dependent on the level of radiationenergy. Mottling appears reasonably prominent in Volume I; however,because of the higher radiation energy levels mottling may not be apparentin Volume II nor Volume III.1.3 All areas of this standard may
12、be open to agreementbetween the cognizant engineering organization and thesupplier, or specific direction from the cognizant engineeringorganization. These items should be addressed in the purchaseorder or the contract.1.4 These digital reference images are not intended toillustrate the types and de
13、grees of discontinuities found in steelcastings up to 2 in. (50.8 mm) in thickness when performingfilm radiography. If performing film radiography of steelcastings up to 2 in. (50.8 mm) in thickness, refer to ReferenceRadiographs E446.1.5 Only licensed copies of the software and images shall beutili
14、zed for production inspection. A copy of the ASTM/Userlicense agreement shall be kept on file for audit purposes. (SeeNote 4.)NOTE 4Each volume of digital reference images consists of 7 digitaldata files, software to load the desired format and specific instructions onthe loading process. The 34 ref
15、erence images in each volume illustrate sixcategories of graded discontinuities and four categories of ungradeddiscontinuities and contain an image of a step wedge. Available fromASTM International Headquarters, Order No: RRE286801 for Volume I,RRE286802 for Volume II, and RRE286803 for Volume III.1
16、.6 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1This standard is under the jurisdiction of ASTM Committee E07 on Nonde-structive Test
17、ing and is the direct responsibility of Subcommittee E07.02 onReference Radiological Images.Current edition approved Nov. 1, 2017. Published November 2017. Originallyapproved in 2013. Last previous edition approved in 2013 as E2868-17. DOI:10.1520/E2868-13.*A Summary of Changes section appears at th
18、e end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for t
19、heDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.11.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of th
20、is standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Dec
21、ision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E446 Reference Radiographs for Steel Castings Up to 2 in.(50.8 mm) in ThicknessE
22、1316 Terminology for Nondestructive ExaminationsE2002 Practice for Determining Total Image Unsharpnessand Basic Spatial Resolution in Radiography and Radios-copy2.2 SMPTE Practice:3RP133 SMPTE Recommended Practice Specifications forMedical Diagnostic Imaging Test Pattern for TelevisionMonitors and H
23、ard-Copy Recording Cameras2.3 ASTM Adjunct:4RRE286801 Digital Reference Images for Inspection ofSteel Castings Up to 2 in. (50.8 mm) in Thickness(Volume I) : Medium Voltage (nominal 250-kVp) X-RayReference ImagesRRE286802 Digital Reference Images for Inspection ofSteel Castings Up to 2 in. (50.8 mm)
24、 in Thickness(Volume II): 1-MV X Rays and Iridium-192 ReferenceImagesRRE286803 Digital Reference Images for Inspection ofSteel Castings Up to 2 in. (50.8 mm) in Thickness(Volume III): 2-MV to 4-MV X Rays and Cobalt-60Reference Images3. Terminology3.1 Definitions:3.1.1 Definitions of terms used in th
25、is standard may befound in Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 aliasing, nartifacts that appear in an image when thespatial frequency of the input is higher than the output iscapable of reproducing. This will often appear as jagged orstepped sections in a line
26、or as moir patterns.3.2.2 classification specification, na set of user definedacceptance criterion that prescribes the radiographic workman-ship discontinuity class requirements for a specified usercasting service application (see Sections 6 and 7).3.2.3 contrast normalization, nthe adjustment of co
27、ntrastbetween the production image and the reference image thatmakes the change in digital driving level versus change inthickness equal for both images.3.2.4 DDL, ndigital driving level also known as monitorpixel value.3.2.5 discontinuity category, na nomenclature systemused for grouping discontinu
28、ity types. For example: linearshrinkage is assigned category “Ca” where “C” represents thegeneral shrinkage category and “a” represents the specificlinear shrinkage discontinuity type.3.2.6 discontinuity class, nan assigned workmanship fab-rication quality rating characterized by a discontinuity typ
29、e,category and severity level. For example: “Ca 2” is a discon-tinuity class comprised of linear shrinkage with a severity levelof “2.”3.2.7 discontinuity severity level, na relative rank in termsof “quantity, size, and distribution” of a collection of discon-tinuities where “1” is the least and “5”
30、 is the greatest “quantity,size, and distribution” present on the reference image. Ex-ample: a severity level of “1” is more restrictive (requires ahigher level of workmanship fabrication quality) than a sever-ity level of “2”.3.2.8 discontinuity type, na specific discontinuity charac-terized by its
31、 cause and appearance. For example: linearshrinkage is a specific discontinuity type.3.2.9 graded illustrations, na category of discontinuitythat is assigned a severity level.3.2.10 measured resolution, nthe characteristic resolutionof a digital radiographic system as measured in accordancewith 10.5
32、.3.2.11 production image, nan image under review forcompliance with this standard.3.2.12 prorating, vassignment of quantity, size, and dis-tribution on a production image in proportion to a similar sizearea of a reference image. For example: a production imagecovers an area that is smaller than the
33、unit area of a referenceimage and the extent of discontinuity on the applicablereference image is reduced proportionately.3.2.13 ungraded illustrations, na category of discontinu-ity without an assigned severity level.4. Significance and Use4.1 Graded reference images are intended to provide a guide
34、enabling recognition of specific casting discontinuity types andrelative severity levels that may be encountered during typicalfabrication processes. Reference images containing ungradeddiscontinuities are provided as a guide for recognition of aspecific casting discontinuity type where severity lev
35、els are notneeded. These reference images are intended as a basis fromwhich manufacturers and purchasers may, by mutualagreement, select particular discontinuity classes to serve asstandards representing minimum levels of acceptability (seeSections 6 and 7).2For referenced ASTM standards, visit the
36、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.3Available from the Society of Motion Picture and Television Engineers, 3Barker Avenue White Plains, NY
37、 10601; or http:/www.smpte.org/smpte_store/4Available from ASTM International Headquarters, Order No: RRE286801 forVolume I, RRE286802 for Volume II, and RRE286803 for Volume III.E2868 1724.2 Reference images represented by this standard may beused, as agreed upon in a purchaser supplier agreement,
38、forenergy levels, thicknesses, or both outside the range of thisstandard when determined applicable for the casting serviceapplication.4.3 Procedures for evaluation of production images usingapplicable reference images of this standard are prescribed inSection 8; however, there may be manufacturing-
39、purchaserissues involving specific casting service applications where itmay be appropriate to modify or alter such requirements.Where such modifications may be appropriate for the castingapplication, all such changes shall be specifically called-out inthe purchaser supplier agreement or contractual
40、document.Section 9 addresses purchaser supplier requisites for whereweld repairs may be required.4.4 Agreement should 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. Det
41、ermination of Radiographic Acceptance Criteria5.1 For purposes of evaluation of castings, a determinationmust be made of the radiographic discontinuity acceptancecriteria to be assigned to individual castings or specific areas ofcastings. The determination of the applicable radiographicdiscontinuity
42、 criteria shall be based on an evaluation of thecasting applications, design, and service requirements. In theseevaluations, consideration shall be given to such factors aspressure, temperature, section thickness, applicable designsafety factor (preferably based on stress analysis), vibration,shock,
43、 resistance to corrosion, involvement of penetratingradiations or radiation products, and involvement of dangerousgases or liquids.5.2 For each individual casting or specific area of a castingto be radiographed, the discontinuity criteria must be clearlyspecified. For example, severity level 2 might
44、 be specified forlinear shrinkage, Category Ca, and severity level 3 for gasporosity, Category A, since the latter are generally much lessdeleterious to tensile properties (see Section 6).6. Acceptance Criteria Specifications6.1 The applicable radiographic discontinuity acceptancecriteria should be
45、designated by the contracting agency informal specifications or on drawings and in specific contractsor orders. The specifications, drawings, contracts, or ordershould also designate the sampling plan for the castings to beradiographed and the extent of radiographic coverage, radio-graphic practice
46、to be followed, image quality desired as wellas the severity of the acceptable discontinuity for the gradedcategories.7. Evaluation Procedure7.1 Select the appropriate digital reference image to matchthe condition to be evaluated in the production image.7.2 Apply contrast adjustments to the referenc
47、e image usingthe method described in Section 10.5.7.3 Evaluation shall be performed against the adjustedreference image.7.4 Compare the production images of the casting submittedfor evaluation with the reference images representing the samegeneral energy range within the thickness range of this stan
48、-dard (unless otherwise specifiedsee Section 4).7.5 When the severity level of discontinuities in the produc-tion image being evaluated is equal to or less than the severitylevel in the specified reference image, that part of the castingrepresented by the production image shall be acceptable. If the
49、production image shows discontinuities of greater severity thanthe reference image, that part of the casting shall be rejected.7.6 A unit area on the production image shall be evaluatedto a unit area of like size on the reference image. Any unitevaluation area that shares a discontinuity with an adjacent unitevaluation area shall meet the minimum unit area acceptabilityrequirements within the combined unit area. When the unitarea of interest of a production image is less than the unit areaof the applicable reference image, such unit area o
