1、Designation: E446 10Standard 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 last revi
2、sion. 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 Department of Defense.1. Scope1.1 These reference radiographs2illustrate various
3、 catego-ries, types, and severity levels of discontinuities occurring insteel castings that have section thicknesses up to 2 in. (50.8mm) (see Note 2). The reference radiograph films are anadjunct to this standard and must be purchased separately fromASTM International, if needed (see 2.2). Categori
4、es andseverity levels for each discontinuity type represented by thesereference radiographs are described in 1.2.NOTE 1The basis of application for these reference radiographsrequires a prior purchaser supplier agreement of radiographic examinationattributes and classification criterion as described
5、 in Sections 4, 6, and 7of this standard.NOTE 2Reference radiographs previously used for this thicknessrange carried the designation E71, but included a now rarely used gammasource, that is, radium. The current document is also updated by inclusionof several recognized shrinkage or C categories and
6、by elimination of thecrack and hot tear categories except for one example of each of thesediscontinuity types. Reference radiographs for thicker sections may befound in Reference Radiograph standards E186 and E280. ReferenceRadiograph standards E446 and E186 provide some overlap of severitylevels fo
7、r similar discontinuity categories within the same energy levelrange (see 4.2, 5.1, and 6.3).1.2 These reference radiographs consist of three separatevolumes (see Note 3) 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 a
8、nd cobalt-60 radiation. Unlessotherwise specified in a purchaser supplier agreement (see 1.1),each volume is for comparison only with production radio-graphs produced with radiation energy levels within the thick-ness range covered by this standard. Each volume consists ofsix categories of graded di
9、scontinuities of increasing severitylevel and four categories of ungraded discontinuities. Refer-ence radiographs containing ungraded discontinuities are pro-vided as a guide for recognition of a specific casting disconti-nuity type where severity levels are not needed. Following is alist of discont
10、inuity categories, types and severity levels for theadjunct reference radiographs of this standard:1.2.1 Category AGas porosity; severity levels 1 through5.1.2.2 Category BSand and slag inclusions; severity levels1 through 5.1.2.3 Category CShrinkage; 4 types:1.2.3.1 CaSeverity levels 1 through 5.1.
11、2.3.2 CbSeverity levels 1 through 5.1.2.3.3 CcSeverity levels 1 through 5.1.2.3.4 Cdcombinations of linear, feathery and spongeshrinkageSeverity 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 GMo
12、ttling; 1 illustration.NOTE 3The reference radiographs consist of the following:Volume I: Medium Voltage (nominal 250 kVp) X-Ray ReferenceRadiographsset of 34 illustrations (nominal 5 by 7 in.) in a 15 by 17-in.ring binder.Volume II: 1-MV X Rays and Iridium-192 Reference RadiographsSetof 34 illustra
13、tions (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 ReferenceRadiographsSet of 34 illustrations (nominal 5 by 7 in.) in a 15 by 17-in.ring binder.NOTE 4Although Category GMottling is listed for all three volumes,the appearance of mottling is depende
14、nt on the level of radiation energy.Mottling appears reasonably prominent in Volume I; however, because ofthe higher radiation energy levels mottling may not be apparent in VolumeII nor Volume III.1.3 The values stated in inch-pound units are to be regardedas the standard. SI values are shown for in
15、formation only.1.4 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 limitations prior to use.
16、1These reference radiographs are under the jurisdiction of ASTM CommitteeE07 on Nondestructive Testing and are the direct responsibility of SubcommitteeE07.02 on Reference Radiological Images.Current edition approved Jan. 1, 2010. Published February 2010. Originallyapproved in 1972. Last previous ed
17、ition approved in 2004 as E446 98(2004)1.DOI: 10.1520/E0446-10.2For ASME Boiler and Pressure Vessel Code applications see related ReferenceRadiographs SE-446 in Section V of that Code.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2
18、. Referenced Documents2.1 ASTM Standards:3E94 Guide for Radiographic ExaminationE186 Reference Radiographs for Heavy-Walled (2 to 412-in. 51 to 114-mm) Steel CastingsE242 Reference Radiographs for Appearances of Radio-graphic Images as Certain Parameters Are ChangedE280 Reference Radiographs for Hea
19、vy-Walled (412 to12-in. 114 to 305-mm) Steel CastingsE1316 Terminology for Nondestructive Examinations2.2 ASTM Adjuncts:4Reference Radiographs for Steel Castings Up to 2 in. (50.8mm) in Thickness:Volume I, Medium Voltage (Nominal 250 kVp) X-Rays5Volume II, 1-MV X-Rays and Iridium-1926Volume III, 2-M
20、V to 4-MV X-Rays and Cobalt-6073. Terminology3.1 DefinitionsFor definitions of terms relating to radio-graphic examination, see Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 production radiographa radiograph under reviewfor compliance with this standard.3.2.2 discontinui
21、ty typea specific discontinuity character-ized by its cause and appearance. For example: linear shrink-age is a specific discontinuity type.3.2.3 discontinuity categorya nomenclature system usedfor grouping discontinuity types. For example: linear shrinkageis assigned category “Ca” where “C” represe
22、nts the generalshrinkage category and “a” represents the specific linearshrinkage discontinuity type.3.2.4 discontinuity severity levela relative rank in termsof “quantity, size and distribution” of a collection of disconti-nuities where “1” is the least and “5” is the greatest “quantity,size and di
23、stribution” present on the reference radiograph.Example: a severity level of “1” is more restrictive (requires ahigher level of workmanship fabrication quality) than a sever-ity level of “2”.3.2.5 discontinuity classan assigned workmanship fabri-cation quality rating characterized by a discontinuity
24、 type,category and severity level. For example: “Ca 2” is a discon-tinuity class comprised of linear shrinkage with a severity levelof “2”.3.2.6 classification specificationa set of user defined ac-ceptance criterion that prescribes the radiographic workman-ship discontinuity class requirements for
25、a specified usercasting service application (see Sections 6 and 7).3.2.7 graded illustrationa category of discontinuity that isassigned a severity level.3.2.8 ungraded illustrationa category of discontinuitywithout an assigned severity level.3.2.9 proratingassignment of quantity, size and distribu-t
26、ion on a production radiograph in proportion to a similar sizearea of a reference radiograph. For example: a productionradiograph covers an area that is smaller than the unit area ofa reference radiograph and the extent of discontinuity on theapplicable reference radiograph is reduced proportionatel
27、y.4. Significance and Use4.1 Graded reference radiographs are intended to provide aguide enabling recognition of specific casting discontinuitytypes and relative severity levels that may be encounteredduring typical fabrication processes. Reference radiographscontaining ungraded discontinuities are
28、provided as a guide forrecognition of a specific casting discontinuity type whereseverity levels are not needed. These reference radiographs areintended as a basis from which manufacturers and purchasersmay, by mutual agreement, select particular discontinuityclasses to serve as standards representi
29、ng minimum levels ofacceptability (see Sections 6 and 7).4.2 Reference radiographs represented by this standard maybe used, as agreed upon in a purchaser supplier agreement, forenergy levels, thicknesses or both outside the range of thisstandard when determined applicable for the casting serviceappl
30、ication. Severity levels of similar discontinuity categoriesand energy level range of E186 reference radiographs mayalternatively be used, as determined appropriate for the castingservice application, if so agreed upon in the purchaser supplieragreement (see Note 2 and 5.1).4.3 Procedures for evalua
31、tion of production radiographsusing applicable reference radiographs of this standard areprescribed in Section 8; however, there may be manufacturing-purchaser issues involving specific casting service applicationswhere it may be appropriate to modify or alter such require-ments. Where such modifica
32、tions may be appropriate for thecasting application, all such changes shall be specificallycalled-out in the purchaser supplier agreement or contractualdocument. Section 9 addresses purchaser supplier requisites forwhere weld repairs may be required.5. Method of Preparation5.1 The original radiograp
33、hs used to prepare the adjunctreference radiographs were produced on ASTM Class I or IIfilm systems by the respective use of 250-kV X-ray, Iridium-192 and Cobalt-60 sources of radiation. The original radio-graphs were made with penetrameter sensitivity as determinedby ASTM penetrameters (see Guide E
34、94) of 2-2T. The adjunctreference radiographs are reproductions prepared to an opticaldensity of 2.00 to 2.25 and have substantially retained thecontrast of the original radiographs. In preparing these refer-ence radiographs, the objective was to obtain progressivelygraduated severity levels for eac
35、h graded discontinuity cat-egory of this standard. Additionally, some overlap of severitylevels may occur for discontinuity categories of this standardand similar discontinuity categories of E186 reference radio-graphs within the same energy level range. For example,aggregate gas porosity severity l
36、evel 5 of this standard exceedsaggregate gas porosity severity level 1 of Reference Radio-graph E186 (see 6.3).3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the s
37、tandards Document Summary page onthe ASTM website.4Available from ASTM Headquarters.5Order RRE044601.6Order RRE044602.7Order RRE044603.E446 1025.2 Film DeteriorationRadiographic films are subject towear and tear from handling and use. The extent to which theimage deteriorates over time is a function
38、 of storage condi-tions, care in handling and amount of use. Reference radio-graph films are no exception and may exhibit a loss in imagequality over time. The radiographs should therefore be peri-odically examined for signs of wear and tear, includingscratches, abrasions, stains, and so forth. Any
39、reference radio-graphs which show signs of excessive wear and tear whichcould influence the interpretation and use of the radiographsshould be replaced.6. Determination of Radiographic Classification6.1 For purposes of evaluation of castings, a determinationmust be made of the radiographic discontin
40、uity classificationsto be assigned to individual castings or specific areas ofcastings. The determination of the applicable radiographicdiscontinuity classification shall be based on an evaluation ofthe casting applications, design, and service requirements. Inthese evaluations, consideration shall
41、be given to such factorsas pressure, temperature, section thickness, applicable designsafety factor (preferably based on stress analysis), vibration,shock, resistance to corrosion, involvement of penetratingradiations or radiation products, and involvement of dangerousgases or liquids.6.2 For each i
42、ndividual casting or specific area of a castingto be radiographed, the discontinuity class must be clearlyspecified. For example, severity level 2 might be specified forlinear shrinkage, Category Ca, and severity level 3 for gasporosity, Category A, since the latter are generally much lessdeleteriou
43、s to tensile properties (see Section 7).6.3 When determining discontinuity severity levels for in-dividual castings spanning multiple thickness ranges outsidethe range of this standard, consideration should be given to thepotential for overlaping severity levels as described in 4.2 and5.1.6.4 Produc
44、tion radiographs which are compared to refer-ence radiographs should have an optical density in the area ofinterest in accordance with Guide E94 and a specified mini-mum radiographic sensitivity (quality level) of 2 % (2-2T).Other radiographic quality levels or optical densities may bedesignated, bu
45、t then a corresponding change in severity levelfor each discontinuity category should be anticipated and hencespecified.7. Classification Specifications7.1 The applicable radiographic discontinuity classificationshould be designated by the contracting agency in formalspecifications or on drawings an
46、d in specific contracts ororders. The specifications, drawings, contracts, or order shouldalso designate the sampling plan for the castings to beradiographed and the extent of radiographic coverage, radio-graphic practice to be followed (Guide E94), image qualitydesired (Note 5) as well as the sever
47、ity of the acceptablediscontinuity for the graded categories.NOTE 5For description of radiographic sensitivity or quality levels,see Guide E94 and Reference Radiographs E242.8. Evaluation Procedure8.1 Compare the production radiographs of the castingsubmitted for evaluation with the reference radiog
48、raphs ex-posed at an equivalent energy range within the thickness rangeof this standard (unless otherwise specifiedsee Section 4).8.2 When the severity level of discontinuities in the produc-tion radiograph being evaluated is equal to or less than theseverity level in the specified reference radiogr
49、aph, that part ofthe casting represented by the production radiograph shall beacceptable. If the production radiograph shows discontinuitiesof greater severity than the reference radiograph, that part ofthe casting shall be rejected.8.3 A unit area on the production radiograph shall beevaluated to a unit area of like size on the reference radiograph.Any unit evaluation area that shares a discontinuity with anadjacent unit evaluation area shall meet the minimum unit areaacceptability requirements within the combined unit area.When the unit area o
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