ASTM E689-2010 8750 Standard Reference Radiographs for Ductile Iron Castings《球墨铸铁件的标准参考底片》.pdf

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1、Designation: E689 10Standard 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 parenthese

2、s 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 castingreference radiographs E446, E186, and E280 to ductile ironcastings when determined appropriate for sp

3、ecific applications(see Section 4).1.2 The reference radiograph films are an adjunct to E446,E186,orE280, and must be purchased separately from ASTMInternational, if needed (see 2.1). Categories and severitylevels for each discontinuity type represented by these refer-ence radiographs are described

4、within each applicable standardabove.NOTE 1The basis of application for these reference radiographsrequires a prior purchaser supplier agreement of radiographic examinationattributes and classification criterion as described in Sections 4, 5, and 6of this standard.1.3 This standard does not purport

5、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.2. Referenced Documents2.1 ASTM Standards:2E94 Gui

6、de 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 Heavy-Walled (412 to12-in. 114 to 305-mm) Steel Cast

7、ingsE446 Reference Radiographs for Steel Castings Up to 2 in.51 mm in ThicknessE1316 Terminology for Nondestructive Examinations3. 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

8、production radiographa radiograph under reviewfor compliance with this standard.3.2.2 Discontinuity typea specific discontinuity character-ized by its cause and appearance. For example, linear shrinkageis a specific discontinuity type.3.2.3 discontinuity categorya nomenclature system usedfor groupin

9、g discontinuity types. For example, linear shrinkageis assigned category “Ca” where “C” represents 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 coll

10、ection of disconti-nuities where “1” is the least and “5” is the greatest “quantity,size and distribution” present on the reference radiograph. Forexample, a severity level of “1” is more restrictive (requires ahigher level of fabrication quality) than a severity level of “2”.3.2.5 discontinuity cla

11、ssan assigned fabrication qualityrating characterized by a discontinuity type, category andseverity level. For example, “Ca 2” is a discontinuity classcomprised of linear shrinkage with a severity level of “2”.3.2.6 classification specificationa set of user defined ac-ceptance criterion that prescri

12、bes the radiographic discontinu-ity class requirements for a specified user casting serviceapplication (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

13、.3.2.9 proratingassignment of quantity, size and distribu-tion 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 t

14、heapplicable reference radiograph is reduced proportionately.4. Significance and Use4.1 The casting process has demonstrated radiographicsimilarities between internal discontinuities for ductile castiron and cast steel to the extent that the reference radiographs1This reference radiograph is under t

15、he jurisdiction ofASTM Committee E07 onNondestructive Testing and is the direct responsibility of Subcommittee E07.02 onReference Radiological Images.Current edition approved Jan. 1, 2010. Published February 2010. Originallyapproved in 1979. Last previous edition approved in 2003 as E689 95(2004)1.D

16、OI: 10.1520/E0689-10.2For 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 standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr

17、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.for steel castings are applicable. The exact application andusage of discontinuity classifications contained within steelcasting reference radiographs must, however, give consider-ation to the differences in material properti

18、es between cast steeland ductile cast iron. In some applications, reference radio-graphs for steel castings may not be entirely applicable toductile cast iron material dependent upon design or other usagecriteria.4.2 When employing steel casting reference radiographs toevaluate ductile iron castings

19、, the applicable E446, E186,orE280 steel casting written standard shall also be used forspecific guidance and evaluation procedures.4.3 These reference radiographs are intended as a basis fromwhich manufacturers and purchasers may, by mutual agree-ment, select particular discontinuity classes to ser

20、ve as stan-dards representing minimum levels of acceptability. Referenceradiographs represented by these steel casting standards maybe used, as agreed upon in a purchaser supplier agreement, forradiation energy levels, thicknesses or both outside the range ofthese standards when determined applicabl

21、e for the castingservice application5. Determination of Radiographic Classification5.1 For purposes of evaluation of castings, a determinationmust be made of the radiographic discontinuity classificationsto be assigned to individual castings or specific areas ofcastings. The determination of the app

22、licable radiographicdiscontinuity classification shall be based on an evaluation ofthe casting applications, design, and service requirements. Inthese evaluations, consideration shall be given to such factorsas pressure, temperature, section thickness, applicable designsafety factor, vibration, shoc

23、k, resistance to corrosion, involve-ment of penetrating radiations or radiation products, andinvolvement of dangerous gases or liquids.5.2 For each individual casting or specific area of a castingto be radiographed, the discontinuity class must be clearlyspecified. For example, severity level 2 migh

24、t 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).5.3 When determining discontinuity severity levels for in-dividual castings spanning multiple thickness ranges

25、outsidethe range of this standard, consideration should be given to thepotential for overlapping severity levels as described in theapplicable written standard.5.4 Production radiographs which are compared to refer-ence radiographs should have an optical density in the area ofinterest in accordance

26、with Guide E94 and a specified mini-mum radiographic sensitivity (quality level) of 2 % (2-2T).1Other radiographic quality levels or optical densities may bedesignated, but then a corresponding change in severity levelfor each discontinuity category should be anticipated and hencespecified.6. Classi

27、fication Specifications6.1 The applicable radiographic discontinuity classificationshould be designated by the contracting agency in formalspecifications, on drawings, or within specific contracts ororders. The specifications, drawings, contracts or order shouldalso designate the examination samplin

28、g plan for the castingsto be radiographed, the extent of radiographic coverage,radiographic practice to be followed (that is, Guide E94),image quality desired (see Note 2) as well as the severity of theacceptable discontinuity for the graded discontinuities.NOTE 2For description of radiographic sens

29、itivity or quality levels,see Guide E94 and Reference Radiograph standard E242.7. Evaluation Procedure7.1 Compare the production radiographs of the castingsubmitted for evaluation with the reference radiographs ex-posed at an equivalent energy range within the thickness rangeof the applicable standa

30、rd (unless otherwise specifiedseeSection 4).7.2 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 radiograph, that part ofthe casting represented by the production radiograph shall beacceptab

31、le. If the production radiograph shows discontinuitiesof greater severity than the reference radiograph, that part ofthe casting shall be rejected.7.3 A unit area on the production radiograph shall beevaluated to a unit area of like size on the reference radiograph.Any evaluation unit area that shar

32、es a discontinuity with anadjacent unit evaluation area shall meet the minimum unit areaacceptability requirements within the combined unit area.When the unit area of interest of a production radiograph is lessthan the unit area of the applicable reference radiograph, suchunit area of the production

33、 radiograph shall be prorated to thereference radiographic area.7.4 When two or more categories of discontinuity arepresent in the same production radiograph, the predominatingdiscontinuities, if unacceptable, shall govern without regard tothe other categories of discontinuity and the casting reject

34、ed.7.5 When two or more categories of discontinuity arepresent to an extent equal to the maximum permissible level asshown in the applicable standards for each category, then thatpart of the casting shall be judged unacceptable. When two ormore categories of discontinuity are present in the sameradi

35、ograph to an extent less than the maximum permissiblelevel, as shown in the applicable standards for each category,the severity shall be evaluated by the overall aggregatecondition. The aggregate condition is defined as the balance ofquantity, size and distribution of the collection of discontinui-t

36、ies and shall not exceed the aggregate condition of theapplicable reference radiograph.7.6 Reference radiographs are provided showing a varietyof shrinkage discontinuity types. Production radiographs show-ing shrinkage shall be judged by the most representativereference radiograph.7.7 This standard

37、does not specify limiting criteria for asingle size of discontinuity, maximum number of discontinui-ties per unit area evaluated, specific dimensional spacingand/or alignment criterion between individual discontinuitiesor any other undefined discontinuity patterns. Unless otherwisespecified by a pur

38、chaser supplier agreement (see Section 4),these discontinuity conditions on production radiographs shallbe evaluated as aggregate conditions as defined in 7.5.E689 1027.8 In general, there is no limit as to the extent of acceptablediscontinuities in a casting, provided that no unit evaluationarea th

39、roughout the casting contains discontinuities that exceedthe severity of discontinuities in the applicable referenceradiographs.7.9 Reference radiographs in this standard do not illustrateelongated or “worm hole” type of gas discontinuities. Whenthis condition occurs in a production radiograph, it s

40、hall beevaluated by comparison with the most representative refer-ence radiograph.7.9.1 When the exposing radiation source has been placedperpendicular to the length of the gas hole, evaluate theproduction radiograph with a shrinkage reference radiograph.7.9.2 When the exposing radiation source has

41、been placeddiametrically or “into” the diameter of the gas hole, evaluatethe production radiograph with a gas reference radiograph.7.10 A diffraction mottling pattern can occur on films ofparts and sections where the grain size is large enough to be anappreciable fraction of the material thickness (

42、see Note 3). Ifdiffraction mottling is suspected, there are a number of ways todemonstrate its presence. The diffraction mottling patternshown in these cases is dependent principally upon the crystalgeometry and the orientation of the crystals to the incidentradiation. Therefore, for a given specime

43、n, any change in thisorientation will affect the diffraction pattern dramatically. Thiscan be accomplished by a slight, 1 to 5 tilt of the part, withrespect to the radiation beam or simply by shifting the centerline of the radiation beam to a slightly different location fromthe first exposure. Indic

44、ations from any porosity, shrinkage, orother discontinuity will move only slightly, while any mottlingpatterns present will change dramatically. If it is necessary ordesirable to eliminate the mottling, the kV may be raised toreduce the amount of diffraction radiation. However, cautionshould be used

45、 so that the kV is not raised to the point thatsensitivity is reduced excessively. If diffraction mottling isdemonstrated to be present on a radiograph, this condition shallnot be considered as prejudicial in evaluating the radiograph.NOTE 3Mottling is often associated with thin sections of austenit

46、icsteels, and copper base alloys such as copper nickel, tin bronzes, andnickel copper.7.11 Hot tears and cracks exhibited on production radio-graphs may at times resemble linear type shrinkage. Whendoubt exists whether such indications are cracks or tears, or arelinear shrinkage, all surfaces in the

47、 area of interest shall beground and magnetic particle or liquid penetrant inspected asapplicable. The extent and depth of grinding may requireengineering judgment. If the indication does not appear on thesurface, that indication shall be considered shrinkage.7.12 The radiographic density of discont

48、inuities in compari-son with background density is a variable dependent ontechnical factors. It shall not be used as a criterion foracceptance or rejection in comparison with reference radio-graphs.8. Weld Repair of Castings8.1 When radiographic quality castings are repaired bywelding, the reference

49、 radiographs to be used in the evaluationof the repaired sections must be specifically agreed uponbetween purchaser and supplier.8.2 When casting discontinuities are removed for repairs,only the extent of discontinuity required to meet applicablereference standards need be removed9. Keywords9.1 classification; discontinuity; ductile iron castings;gamma ray; reference radiographs; X-rayASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expres