1、Designation: E689 10E689 15Standard Reference Radiographs forDuctile Iron Castings1This standard is issued under the fixed designation E689; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in par
2、entheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This standard extends the application of steel casting reference radiographs E446, E186, and E280 to ductile iron castingswhen determined appropriat
3、e for specific applications (see Section 4).1.2 The reference radiograph films are an adjunct to E446, E186, or E280, and must be purchased separately from ASTMInternational, if needed (see 2.1). Categories and severity levels for each discontinuity type represented by these referenceradiographs are
4、 described within each applicable standard above.NOTE 1The basis of application for these reference radiographs requires a prior purchaser supplier agreement of radiographic examination attributesand classification criterion as described in Sections 4, 5, and 6 of this standard.1.3 From time to time
5、, there may be minor changes to the process for manufacturing of the reference 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
6、 the Illustration Monitoring Subcommittee and allreference radiographs 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 standar
7、dregardless of the date of production or the revision level of the text standard.1.4 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 de
8、termine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E94 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
9、as Certain Parameters are ChangedE280 Reference Radiographs for Heavy-Walled (412 to 12 in. (114 to 305 mm) Steel CastingsE446 Reference Radiographs for Steel Castings Up to 2 in. (50.8 mm) in ThicknessE1316 Terminology for Nondestructive Examinations3. Terminology3.1 DefinitionsFor definitions of t
10、erms relating to radiographic examination, see Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 production radiographclassification specificationa radiograph under review for compliance with this standard.set ofuser defined acceptance criterion that prescribes the radiograp
11、hic discontinuity class requirements for a specified user castingservice application (see Sections 6 and 7).3.2.2 Discontinuity typea specific discontinuity characterized by its cause and appearance. For example, linear shrinkage isa specific discontinuity type.1 This reference radiograph is under t
12、he jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.02 onReference Radiological Images.Current edition approved Jan. 1, 2010Sept. 1, 2015. Published February 2010September 2015. Originally approved in 1979. Last previous edition approv
13、ed in 20032010as E689 95E689 10.(2004)1. DOI: 10.1520/E0689-10.10.1520/E0689-15.2 For 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 o
14、n the ASTM website.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 technically possible to adequately depict all changes accurately, ASTM recommends that user
15、s 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 Box C700, West Conshohocken, PA 19428-2959. United States13.2.2 discontinuity categorya
16、 nomenclature system used for grouping discontinuity types. For example, linear shrinkage isassigned category “Ca” where “C” represents the general shrinkage category and “a” represents the specific linear shrinkagediscontinuity type.3.2.3 discontinuity classan assigned fabrication quality rating ch
17、aracterized by a discontinuity type, category and severitylevel. For example, “Ca 2” is a discontinuity class comprised of linear shrinkage with a severity level of “2”.3.2.4 discontinuity severity levela relative rank in terms of “quantity, size and distribution” of a collection of discontinuitiesw
18、here “1” is the least and “5” is the greatest “quantity, size and distribution” present on the reference radiograph. For example,a severity level of “1” is more restrictive (requires a higher level of fabrication quality) than a severity level of “2”.3.2.5 discontinuity classtypean assigned fabricat
19、ion quality rating characterized by a discontinuity type, category andseverity level. For example, “Ca 2” is a discontinuity class comprised of linear shrinkage with a severity level of “2”.a specificdiscontinuity characterized by its cause and appearance. For example, linear shrinkage is a specific
20、 discontinuity type.3.2.6 classification specificationa set of user defined acceptance criterion that prescribes the radiographic discontinuity classrequirements for a specified user casting service application (see Sections 6 and 7).3.2.6 graded illustrationa category of discontinuity that is assig
21、ned a severity level.3.2.7 ungraded illustrationproduction radiographa category of discontinuity without an assigned severity level.radiographunder review for compliance with this standard.3.2.8 proratingassignment of quantity, size and distribution on a production radiograph in proportion to a simi
22、lar 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 discontinuity on the applicable reference radiograph is reduced proportionately.3.2.9 ungraded illustrationa category of discontin
23、uity without an assigned severity level.4. Significance and Use4.1 The casting process has demonstrated radiographic similarities between internal discontinuities for ductile cast iron and caststeel to the extent that the reference radiographs for steel castings are applicable. The exact application
24、 and usage of discontinuityclassifications contained within steel casting reference radiographs must, however, give consideration to the differences in materialproperties between cast steel and ductile cast iron. In some applications, reference radiographs for steel castings may not be entirelyappli
25、cable to ductile cast iron material dependent upon design or other usage criteria.4.2 When employing steel casting reference radiographs to evaluate ductile iron castings, the applicable E446, E186, or E280steel casting written standard shall also be used for specific guidance and evaluation procedu
26、res.4.3 These reference radiographs are intended as a basis from which manufacturers and purchasers may, by mutual agreement,select particular discontinuity classes to serve as standards representing minimum levels of acceptability. Reference radiographsrepresented by these steel casting standards m
27、ay be used, as agreed upon in a purchaser supplier agreement, for radiation energylevels, thicknesses or both outside the range of these standards when determined applicable for the casting service application5. Determination of Radiographic Classification5.1 For purposes of evaluation of castings,
28、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, and ser
29、vice requirements. In these evaluations,consideration shall be given to such factors as pressure, temperature, section thickness, applicable design safety factor, vibration,shock, resistance to corrosion, involvement of penetrating radiations or radiation products, and involvement of dangerous gases
30、or liquids.5.2 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 porosity, CategoryA, since the latter are ge
31、nerally much less deleterious to tensile properties (see Section 6).5.3 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 overlapping severity levels as descr
32、ibed in the applicable writtenstandard.5.4 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 2 % (2-2T).1 Other radiographicquality
33、levels or optical densities may be designated, but then a corresponding change in severity level for each discontinuitycategory should be anticipated and hence specified.6. Classification Specifications6.1 The applicable radiographic discontinuity classification should be designated by the contracti
34、ng agency in formalspecifications, on drawings, or within specific contracts or orders. The specifications, drawings, contracts or order should alsoE689 152designate the examination sampling plan for the castings to be radiographed, the extent of radiographic coverage, radiographicpractice to be fol
35、lowed (that is, Guide E94), image quality desired (see Note 2) as well as the severity of the acceptablediscontinuity for the graded discontinuities.NOTE 2For description of radiographic sensitivity or quality levels, see Guide E94 and Reference Radiograph standard E242.7. Evaluation Procedure7.1 Co
36、mpare the production radiographs of the casting submitted for evaluation with the reference radiographs exposed at anequivalent energy range within the thickness range of the applicable standard (unless otherwise specifiedsee Section 4).7.2 When the severity level of discontinuities in the productio
37、n radiograph being evaluated is equal to or less than the severitylevel in the specified reference radiograph, that part of the casting represented by the production radiograph shall be acceptable.If the production radiograph shows discontinuities of greater severity than the reference radiograph, t
38、hat part of the casting shallbe rejected.7.3 A unit area on the production radiograph shall be evaluated to a unit area of like size on the reference radiograph. Anyevaluation unit area that shares a discontinuity with an adjacent unit evaluation area shall meet the minimum unit area acceptabilityre
39、quirements within the combined unit area. When the unit area of interest of a production radiograph is less than the unit areaof the applicable reference radiograph, such unit area of the production radiograph shall be prorated to the reference radiographicarea.7.4 When two or more categories of dis
40、continuity are present in the same production radiograph, the predominatingdiscontinuities, if unacceptable, shall govern without regard to the other categories of discontinuity and the casting rejected.7.5 When two or more categories of discontinuity are present to an extent equal to the maximum pe
41、rmissible level as shownin the applicable standards for each category, then that part of the casting shall be judged unacceptable. When two or morecategories of discontinuity are present in the same radiograph to an extent less than the maximum permissible level, as shown inthe applicable standards
42、for each category, the severity shall be evaluated by the overall aggregate condition. The aggregatecondition is defined as the balance of quantity, size and distribution of the collection of discontinuities and shall not exceed theaggregate condition of the applicable reference radiograph.7.6 Refer
43、ence radiographs are provided showing a variety of shrinkage discontinuity types. Production radiographs showingshrinkage shall be judged by the most representative reference radiograph.7.7 This standard does not specify limiting criteria for a single size of discontinuity, maximum number of discont
44、inuities perunit area evaluated, specific dimensional spacing and/or alignment criterion between individual discontinuities or any otherundefined discontinuity patterns. Unless otherwise specified by a purchaser supplier agreement (see Section 4), these discontinuityconditions on production radiogra
45、phs shall be evaluated as aggregate conditions as defined in 7.5.7.8 In general, there is no limit as to the extent of acceptable discontinuities in a casting, provided that no unit evaluation areathroughout the casting contains discontinuities that exceed the severity of discontinuities in the appl
46、icable reference radiographs.7.9 Reference radiographs in this standard do not illustrate elongated or “worm hole” type of gas discontinuities. When thiscondition occurs in a production radiograph, it shall be evaluated by comparison with the most representative reference radiograph.7.9.1 When the e
47、xposing radiation source has been placed perpendicular to the length of the gas hole, evaluate the productionradiograph with a shrinkage reference radiograph.7.9.2 When the exposing radiation source has been placed diametrically or “into” the diameter of the gas hole, evaluate theproduction radiogra
48、ph with a gas reference radiograph.7.10 A diffraction mottling pattern can occur on films of parts and sections where the grain size is large enough to be anappreciable fraction of the material thickness (see Note 3). If diffraction mottling is suspected, there are a number of ways todemonstrate its
49、 presence. The diffraction mottling pattern shown in these cases is dependent principally upon the crystal geometryand the orientation of the crystals to the incident radiation. Therefore, for a given specimen, any change in this orientation willaffect the diffraction pattern dramatically. This can be accomplished by a slight, 1 to 5 tilt of the part, with respect to the radiationbeam or simply by shifting the center line of the radiation beam to a slightly different location from the first exposure. Indicationsfrom any porosity, shrinkage, or other disco
