1、Designation: E446 14E446 15Standard Reference Radiographs forSteel Castings Up to 2 in. (50.8 mm) in Thickness1This standard is issued under the fixed designation E446; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These reference radiographs2 illus
3、trate various categories, types, and severity levels of discontinuities occurring in steelcastings that have section thicknesses up to 2 in. (50.8 mm) (see Note 2). The reference radiograph films are an adjunct to thisstandard and must be purchased separately from ASTM International, if needed (see
4、2.2). Categories and severity levels for eachdiscontinuity type represented by these reference radiographs are described in 1.3.NOTE 1The basis of application for these reference radiographs requires a prior purchaser supplier agreement of radiographic examination attributesand classification criter
5、ion as described in Sections 4, 6, and 7 of this standard.NOTE 2Reference radiographs previously used for this thickness range carried the designation E71, but included a now rarely used gamma source,that is, radium. The current document is also updated by inclusion of several recognized shrinkage o
6、r C categories and by elimination of the crack andhot tear categories except for one example of each of these discontinuity types. Reference radiographs for thicker sections may be found in ReferenceRadiograph standards E186 and E280. Reference Radiograph standards E446 and E186 provide some overlap
7、 of severity levels for similar discontinuitycategories within the same energy level range (see 4.2, 5.1, and 6.3).1.2 These film reference radiographs are not intended to illustrate the types and degrees of discontinuities found in steel castingswhen performing digital radiography. If performing di
8、gital radiography of steel castings up to 2 in. (50.8 mm) in thickness, referto Digital Reference Image Standard E2868.1.3 These reference radiographs consist of three separate volumes (see Note 3) as follows: (I) medium voltage (nominal250-kV) X rays. X-rays. (II) 1-MV X rays X-rays and Iridium-192
9、 radiation, and (III) 2-MV to 4-MV X rays X-rays and cobalt-60radiation. Unless otherwise specified in a purchaser supplier agreement (see 1.1), each volume is for comparison only withproduction radiographs produced with radiation energy levels within the thickness range covered by this standard. Ea
10、ch volumeconsists of six categories of graded discontinuities of increasing severity level and four categories of ungraded discontinuities.Reference radiographs containing ungraded discontinuities are provided as a guide for recognition of a specific castingdiscontinuity type where severity levels a
11、re not needed. Following is a list of discontinuity categories, types and severity levelsfor the adjunct reference radiographs of this standard:1.3.1 Category AGas porosity; severity levels 1 through 5.1.3.2 Category BSand and slag inclusions; severity levels 1 through 5.1.3.3 Category CShrinkage; 4
12、 types:1.3.3.1 Calinear shrinkageSeverity levels 1 through 5.1.3.3.2 Cbfeathery shrinkageSeverity levels 1 through 5.1.3.3.3 Ccsponge shrinkageSeverity levels 1 through 5.1.3.3.4 Cdcombinations of linear, feathery and sponge shrinkageSeverity levels 1 through 5.1.3.4 Category DCrack; 1 illustration.
13、1.3.5 Category EHot tear; 1 illustration.1.3.6 Category FInsert; 1 illustration.1.3.7 Category GMottling; 1 illustration.NOTE 3The reference radiographs consist of the following:Volume I: Medium Voltage (nominal 250 kVp) X-RayX-ray Reference Radiographsset of 34 illustrations (nominal 5 by 7 in.) in
14、 a 15 by 17-in. ringbinder.Volume II: 1-MV X Rays X-rays and Iridium-192 Reference RadiographsSet of 34 illustrations (nominal 5 by 7 in.) in a 15 by 17-in. ring binder.1 These reference radiographs are under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and are the direct respons
15、ibility of Subcommittee E07.02on Reference Radiological Images.Current edition approved Oct. 1, 2014Sept. 1, 2015. Published October 2014September 2015. Originally approved in 1972. Last previous edition approved in 20102014as E446 10.E446 14. DOI: 10.1520/E0446-14.10.1520/E0446-15.2 For ASME Boiler
16、 and Pressure Vessel Code applications see related Reference Radiographs SE-446 in Section V of that Code.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be tech
17、nically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO
18、Box C700, West Conshohocken, PA 19428-2959. United States1Volume III: 2-MV to 4-MV X Rays X-rays and Cobalt-60 Reference RadiographsSet of 34 illustrations (nominal 5 by 7 in.) in a 15 by 17-in. ringbinder.NOTE 4Although Category GMottling is listed for all three volumes, the appearance of mottling
19、is dependent on the level of radiation energy.Mottling appears reasonably prominent in Volume I; however, because of the higher radiation energy levels mottling may not be apparent in Volume IInor Volume III.1.4 From time to time, there may be minor changes to the process for manufacturing of the re
20、ference radiograph adjunctmaterials. These changes could include changes in the films or processing chemicals used, changes in the dies or printing for thecardboard mats, etc.; however, in all cases, these changes are reviewed by the Illustration Monitoring Subcommittee and allreference radiographs
21、are reviewed against a fixed prototype image to ensure that there are no changes to the acceptance levelrepresented by the reference radiographs. Therefore, the adjunct reference radiographs remain valid for use with this standardregardless of the date of production or the revision level of the text
22、 standard.1.5 The values stated in inch-pound units are to be regarded as the standard. SI values are shown for information only.standard.The values given in parentheses are mathematical conversions to SI units that are provided for information only and are notconsidered standard.1.6 This standard d
23、oes not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Stan
24、dards:3E94 Guide for Radiographic ExaminationE186 Reference Radiographs for Heavy-Walled (2 to 412 in. (50.8 to 114 mm) Steel CastingsE242 Reference Radiographs for Appearances of Radiographic Images as Certain Parameters are ChangedE280 Reference Radiographs for Heavy-Walled (412 to 12 in. (114 to
25、305 mm) Steel CastingsE1316 Terminology for Nondestructive ExaminationsE2868 Digital Reference Images for Steel Castings up to 2 in. (50.8 mm) in Thickness2.2 ASTM Adjuncts:4Reference Radiographs for Steel Castings Up to 2 in. (50.8 mm) in Thickness:Volume I, Medium Voltage (Nominal 250 kVp) X-Rays5
26、Volume II, 1-MV X-Rays and Iridium-1926Volume III, 2-MV to 4-MV X-Rays and Cobalt-6073. Terminology3.1 DefinitionsFor definitions of terms relating to radiographic examination, see Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 production radiographa radiograph under revi
27、ew for compliance with this standard.3.2.2 discontinuity typea specific discontinuity characterized by its cause and appearance. For example: linear shrinkage is aspecific discontinuity type.3.2.3 discontinuity categorya nomenclature system used for grouping discontinuity types. For example: linear
28、shrinkage isassigned category “Ca” where “C” represents the general shrinkage category and “a” represents the specific linear shrinkagediscontinuity type.3.2.4 discontinuity severity levela relative rank in terms of “quantity, size and distribution” of a collection of discontinuitieswhere “1” is the
29、 least and “5” is the greatest “quantity, size and distribution” present on the reference radiograph. Example: aseverity level of “1” is more restrictive (requires a higher level of workmanship fabrication quality) than a severity level of “2”.3.2.5 discontinuity classan assigned workmanship fabrica
30、tion quality rating characterized by a discontinuity type, categoryand severity level. For example: “Ca 2” is a discontinuity class comprised of linear shrinkage with a severity level of “2”.3.2.6 classification specificationa set of user defined acceptance criterion that prescribes the radiographic
31、 workmanshipdiscontinuity class requirements for a specified user casting service application (see Sections 6 and 7).3.2.7 graded illustrationa category of discontinuity that is assigned a severity level.3.2.8 ungraded illustrationa category of discontinuity without an assigned severity level.3 For
32、referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.4 Available from ASTM Headquarters.5 Order RRE044601.6 Order RRE044
33、602.7 Order RRE044603.E446 1523.2.9 proratingassignment of quantity, size and distribution on a production radiograph in proportion to a similar size area ofa reference radiograph. For example: a production radiograph covers an area that is smaller than the unit area of a referenceradiograph and the
34、 extent of discontinuity on the applicable reference radiograph is reduced proportionately.4. Significance and Use4.1 Graded reference radiographs are intended to provide a guide enabling recognition of specific casting discontinuity typesand relative severity levels that may be encountered during t
35、ypical fabrication processes. Reference radiographs containingungraded discontinuities are provided as a guide for recognition of a specific casting discontinuity type where severity levels arenot needed. These reference radiographs are intended as a basis from which manufacturers and purchasers may
36、, by mutualagreement, select particular discontinuity classes to serve as standards representing minimum levels of acceptability (see Sections6 and 7).4.2 Reference radiographs represented by this standard may be used, as agreed upon in a purchaser supplier agreement, forenergy levels, thicknesses o
37、r both outside the range of this standard when determined applicable for the casting service application.Severity levels of similar discontinuity categories and energy level range of E186 reference radiographs may alternatively be used,as determined appropriate for the casting service application, i
38、f so agreed upon in the purchaser supplier agreement (see Note 2and 5.1).4.3 Procedures for evaluation of production radiographs using applicable reference radiographs of this standard are prescribedin Section 8; however, there may be manufacturing-purchaser issues involving specific casting service
39、 applications where it maybe appropriate to modify or alter such requirements. Where such modifications may be appropriate for the casting application, allsuch changes shall be specifically called-out in the purchaser supplier agreement or contractual document. Section 9 addressespurchaser supplier
40、requisites for where weld repairs may be required.5. Method of Preparation5.1 The original radiographs used to prepare the adjunct reference radiographs were produced on ASTM Class I or II filmsystems by the respective use of 250-kV X-ray, Iridium-192 and Cobalt-60 sources of radiation. The original
41、 radiographs weremade with penetrameter sensitivity as determined by ASTM penetrameters (see Guide E94) of 2-2T. The adjunct referenceradiographs are reproductions prepared to an optical density of 2.00 to 2.25 and have substantially retained the contrast of theoriginal radiographs. In preparing the
42、se reference radiographs, the objective was to obtain progressively graduated severity levelsfor each graded discontinuity category of this standard. Additionally, some overlap of severity levels may occur for discontinuitycategories of this standard and similar discontinuity categories of E186 refe
43、rence radiographs within the same energy level range.For example, aggregate gas porosity severity level 5 of this standard exceeds aggregate gas porosity severity level 1 of ReferenceRadiograph E186 (see 6.3).5.2 Film DeteriorationRadiographic films are subject to wear and tear from handling and use
44、. The extent to which the imagedeteriorates over time is a function of storage conditions, care in handling and amount of use. Reference radiograph films are noexception and may exhibit a loss in image quality over time. The radiographs should therefore be periodically examined for signsof wear and
45、tear, including scratches, abrasions, stains, and so forth.Any reference radiographs which show signs of excessive wearand tear which could influence the interpretation and use of the radiographs should be replaced.6. Determination of Radiographic Classification6.1 For purposes of evaluation of cast
46、ings, a determination must be made of the radiographic discontinuity classifications to beassigned to individual castings or specific areas of castings. The determination of the applicable radiographic discontinuityclassification shall be based on an evaluation of the casting applications, design, a
47、nd service requirements. In these evaluations,consideration shall be given to such factors as pressure, temperature, section thickness, applicable design safety factor (preferablybased on stress analysis), vibration, shock, resistance to corrosion, involvement of penetrating radiations or radiation
48、products, andinvolvement of dangerous gases or liquids.6.2 For each individual casting or specific area of a casting to be radiographed, the discontinuity class must be clearly specified.For example, severity level 2 might be specified for linear shrinkage, Category Ca, and severity level 3 for gas
49、porosity, CategoryA, since the latter are generally much less deleterious to tensile properties (see Section 7).6.3 When determining discontinuity severity levels for individual castings spanning multiple thickness ranges outside the rangeof this standard, consideration should be given to the potential for overlaping severity levels as described in 4.2 and 5.1.6.4 Production radiographs which are compared to reference radiographs should have an optical density in the area of interestin accordance with Guide E94 and a specified minimum radiog
