1、Designation: E446 10E446 14Standard 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 1.21.3.NOTE 1The basis of application for these reference radiographs requires a prior purchaser supplier agreement of radiographic examination attributesand classification cri
5、terion 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 shrinkag
6、e or 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 over
7、lap 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
8、 digital 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. (II) 1-MV X rays and Iridium-192 radiation,
9、and (III) 2-MV to 4-MV X rays and cobalt-60 radiation. Unlessotherwise specified in a purchaser supplier agreement (see 1.1), each volume is for comparison only with production radiographsproduced with radiation energy levels within the thickness range covered by this standard. Each volume consists
10、of six categoriesof graded discontinuities of increasing severity level and four categories of ungraded discontinuities. Reference radiographscontaining ungraded discontinuities are provided as a guide for recognition of a specific casting discontinuity type where severitylevels are not needed. Foll
11、owing is a list of discontinuity categories, types and severity levels for the adjunct reference radiographsof 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 types:1.3.3.1 Cali
12、near 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.1.3.5 Category EHot
13、 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-Ray Reference Radiographsset of 34 illustrations (nominal 5 by 7 in.) in a 15 by 17-in. ring bin
14、der.Volume II: 1-MV X Rays and Iridium-192 Reference RadiographsSet of 34 illustrations (nominal 5 by 7 in.) in a 15 by 17-in. ring binder.Volume III: 2-MV to 4-MV X Rays and Cobalt-60 Reference RadiographsSet of 34 illustrations (nominal 5 by 7 in.) in a 15 by 17-in. ring binder.1 These reference r
15、adiographs are under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and are the direct responsibility of Subcommittee E07.02on Reference Radiological Images.Current edition approved Jan. 1, 2010Oct. 1, 2014. Published February 2010October 2014. Originally approved in 1972. Last pre
16、vious edition approved in 20042010 asE446 98E446 10.(2004)1. DOI: 10.1520/E0446-10.10.1520/E0446-14.2 For ASME Boiler 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 use
17、r of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically 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
18、 published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1NOTE 4Although Category GMottling is listed for all three volumes, the appearance of mottling is dependent on the level of ra
19、diation 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 The values stated in inch-pound units are to be regarded as the standard. SI values are shown for information only.1.5
20、This standard does 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 Documen
21、ts2.1 ASTM Standards: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
22、12-in. (114 to 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 2
23、50 kVp) X-Rays5Volume 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 radiog
24、raph under review 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 e
25、xample: linear 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 discontinuitiesw
26、here “1” is the 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 work
27、manship fabrication 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 t
28、he radiographic 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 severi
29、ty level.3.2.9 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 extent of discontinu
30、ity 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 typical fabrication pr
31、ocesses. Reference radiographs containingungraded discontinuities are provided as a guide for recognition of a specific casting discontinuity type where severity levels are3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Ann
32、ual 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 RRE044602.7 Order RRE044603.E446 142not needed. These reference radiographs are intended as a basis from which manufacturers and
33、 purchasers may, 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
34、, thicknesses or 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
35、 application, if 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
36、casting service 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 addressespurc
37、haser supplier 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 radiatio
38、n. The original 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. I
39、n preparing these 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 categori
40、es of E186 reference 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 h
41、andling and use. 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 si
42、gnsof wear and 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 eva
43、luation of castings, 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 applicat
44、ions, design, and 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 radiation
45、s or radiation 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 l
46、evel 3 for gas 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 give
47、n 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 radiographic sensitivity (quality level) of
48、2 % (2-2T). Other radiographicquality levels or optical densities may be designated, but then a corresponding change in severity level for each discontinuitycategory should be anticipated and hence specified.7. Classification Specifications7.1 The applicable radiographic discontinuity classification
49、 should be designated by the contracting agency in formalspecifications or on drawings and in specific contracts or orders. The specifications, drawings, contracts, or order should alsodesignate the sampling plan for the castings to be radiographed and the extent of radiographic coverage, radiographic practice tobe followed (Guide E94), image quality desired (Note 5) as well as the severity of the acceptable discontinuity for the gradedcategories.NOTE 5For description of radiographic sensitivity or quality levels, see Guide E94 and Referen
