1、Designation: E 446 98 (Reapproved 2004)e1Standard Reference Radiographs forSteel Castings Up to 2 in. 51 mm in Thickness1This standard is issued under the fixed designation E 446; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.e1NOTEEditorial changes were made throu
3、ghout the standard in January 2004.1. Scope1.1 These reference radiographs2illustrate various typesand degrees of discontinuities occurring in steel castings thathave section thicknesses up to 2 in. 51 mm (Note 1).NOTE 1Reference radiographs previously used for this thicknessrange carried the design
4、ation E 71, 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 by elimination of thecrack and hot tear categories except for one example of each of thesediscontinuity types. Reference radio
5、graphs for thicker sections may befound in E 186 and E 280.1.2 These reference illustrations consist of three separatesets (Note 2) as follows: (1) medium voltage (nominal 250-kVp) X rays. (2) 1-MV X rays and Iridium-192 radiation, and(3) 2-MV to 4-MV X rays and cobalt-60 radiation. Each set isfor c
6、omparison only with radiographs produced with equiva-lent radiation. It should be recognized that each energy level isnot applicable to the entire thickness range covered by thisdocument. Each set consists of 6 categories of graded discon-tinuities in increasing severity level and 4 categories ofung
7、raded discontinuities furnished as examples only, as fol-lows: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 5.1.2.3.2 CBSeverity levels 1 through 5.1
8、.2.3.3 CCSeverity levels 1 through 5.1.2.3.4 CDSeverity 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 GMottling; 1 illustration.NOTE 2The illustrations consist of the following:Volume I: Medium
9、Voltage (Nominal 250 kVp) X-Ray ReferenceRadiographsSet of 34 illustrations (5 by 7 in.) in a 15 by 17-in. ringbinder.Volume II: 1-MV X Rays and Iridium-192 Reference RadiographsSetof 34 illustrations (5 by 7 in.) in a 15 by 17-in. ring binder.Volume III: 2-MV to 4-MV X Rays and Cobalt-60 ReferenceR
10、adiographsSet of 34 illustrations (5 by 7 in.) in a 15 by 17-in. ringbinder.NOTE 3Although Category GMottling is listed for all three volumes,the appearance of mottling is dependent on the level of radiation energy.Mottling appears reasonably prominent in Volume I; however, because ofthe higher radi
11、ation 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.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 thi
12、s 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:3E 94 Guide for Radiographic ExaminationE 186 Reference Radiographs for Heavy-Walled (2 to 412-in. 51 to 114-mm) Steel Ca
13、stingsE 242 Reference Radiographs for Appearances of Radio-graphic Images as Certain Parameters Are ChangedE 280 Reference Radiographs for Heavy-Walled (412 to12-in. 114 to 305-mm) Steel CastingsE 1316 Terminology for Nondestructive Examinations2.2 ASTM Adjuncts:4Reference Radiographs for Steel Cast
14、ings Up to 2 in. 51mm in Thickness:1These reference radiographs are under the jurisdiction of ASTM CommitteeE07 on Nondestructive Testing and are the direct responsibility of SubcommitteeE07.02 on Reference Radiographs.Current edition approved January 1, 2004. Published February 2004. Originallyappr
15、oved in 1972. Last previous edition approved in 1998 as E 446 98.2For ASME Boiler and Pressure Vessel Code applications see related ReferenceRadiographs SE-446 in Section V of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceas
16、tm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from ASTM Headquarters.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Volume I, Medium Voltage (
17、Nominal 250 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 used in this docu-ment, see Terminology E 1316, section D.4. Significance and Use4.1 These reference radiographs are intended to provide
18、aguide enabling recognition of discontinuities and their differ-entiation both as to type and severity level, where applicable.4.2 They also provide example radiographic illustrations ofdiscontinuities, that are ungraded, for reference in acceptancestandards, specifications and drawings.4.3 Sets of
19、reference radiographs from which purchasersand suppliers may, by mutual agreement, select particularillustrations to serve as standards representing minimum ac-ceptability are provided. At the same time, the standards soestablished may be unambiguously identified by alphabeticdefect category (or typ
20、e) designation and severity level.4.4 The use of this document is not intended to be restrictedto the specific energy level or to the absolute thickness limitsthat are contained in the document title. The title is intended tobe descriptive and not restrictive. The document may be used,where there is
21、 no other applicable document, for other energylevels or thicknesses or both, for which it is found to beapplicable and for which agreement has been reached betweenpurchaser and manufacturer.5. Method of Preparation5.1 The original radiographs used to prepare these three setsof reference illustratio
22、ns were made from selected sections ofactual production castings by the respective use of 250-kVp Xrays, iridium-192 radiation, and cobalt-60 radiation on Class Iand II film with a sensitivity as determined by standard 2-2Tpenetrameters (Guide E 94). The illustrations have been pre-pared to an optic
23、al density of 2.00 to 2.25 and have been madeto retain the contrast of the original radiographs.5.2 Film DeteriorationRadiographic films are subject towear and tear from handling and use. The extent to which theimage deteriorates over time is a function of storage condi-tions, care in handling and a
24、mount 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 reference radio-graphs which show signs of exce
25、ssive 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 classification to be assignedto individual castings or s
26、pecific areas of castings. The deter-mination of the applicable radiographic classification shall bebased on an evaluation of the casting applications, design, andservice requirements. In these evaluations, consideration shallbe given to such factors as pressure, temperature, sectionthickness, appli
27、cable design safety factor (preferably based onstress analysis), vibration, shock, resistance to corrosion,involvement of penetrating radiations or radiation products,and involvement of dangerous gases or liquids.6.2 For each portion of casting radiographed, the severitylevel for each class of disco
28、ntinuity category should be clearlyspecified. Thus, Severity Level 2 might be specified forshrinkage, Category CA, and Severity Level 3 for Gas Poros-ity, Category A, since the latter are generally much lessdeleterious to tensile properties.7. Classification Specifications7.1 The applicable radiogra
29、phic severity classificationshould be designated by the contracting agency in formalspecifications or on drawings and in specific contracts ororders. The specifications, drawings, contracts, or order shouldalso designate the sampling plan for the castings to beradiographed and the extent of radiogra
30、phic coverage, radio-graphic practice to be followed (Guide E 94), image qualitydesired (Note 4) as well as the severity of the acceptablediscontinuity for the graded categories.NOTE 4For description of sensitivity or quality levels, see Guide E 94and Reference Radiographs E 242.8. Procedure for Eva
31、luation8.1 Compare the production radiographs of the castingsubmitted for evaluation with the reference radiographs ofsimilar thickness that were exposed at an equivalent energyrange.8.2 When the severity level of discontinuities in the produc-tion radiograph being evaluated is equal to or better th
32、an theseverity level in the specified reference radiograph, 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 An area
33、of like size to the reference radiograph shall bethe unit area by which the production radiograph is evaluated,and any such area or any area that shares a discontinuity withan adjacent film area shall meet the requirements as defined foracceptability. When the are of interest of a production radio-g
34、raph is less than the unit area, such area of interest shall beprorated to the reference radiographic area.8.4 When two or more categories of discontinuity arepresent in the same production radiograph, the predominatingdiscontinuities, if unacceptable, shall govern without regard tothe other categor
35、ies of discontinuities, and the casting rejecteduntil satisfactorily repaired.8.5 When two or more categories of discontinuity arepresent to an extent equal to the maximum permissible level asshown in the pertinent standards for each category, then thatpart of the casting shall be judged unacceptabl
36、e until satisfac-torily repaired.5Order RRE044601.6Order RRE044602.7Order RRE044603.E 446 98 (2004)e128.6 Reference radiographs are provided showing a varietyof forms of shrinkage cavities. Production radiographs show-ing shrinkage shall be judged by the most representativereference radiograph.8.7 P
37、roduction radiographs showing porosity, gas, or inclu-sions shall be evaluated by the overall condition with regard tosize, number, and distribution. The aggregate size of disconti-nuities shall not exceed the total accumulation in area of thediscontinuities of the reference radiograph. It is not th
38、e intentthat the maximum size of the illustrated discontinuity shall bethe limiting size for a single production radiographic discon-tinuity, or that the number of discontinuities shown on thereference radiograph shall be the limiting number for produc-tion radiographs. Also, caution should be exerc
39、ised in judginga large discontinuity against a collection of small discontinui-ties on the basis of size alone. Each of the factors of size,number, and distribution must be considered in balance.8.8 Reference radiographs in this standard do not illustrateelongated or “worm hole” type of gas disconti
40、nuities. Whenthis condition occurs in a production radiograph, it shall beevaluated by comparison with the most representative refer-ence radiograph.8.8.1 When the source has been placed perpendicular to thelength of the gas hole, evaluate the production radiograph witha shrinkage reference radiogra
41、ph.8.8.2 When the source has been placed diametricallyor“into” the diameter of the gas hole, evaluate the productionradiograph with a gas reference radiograph.8.9 A diffraction mottling pattern can occur on films of partsand sections where the grain size is large enough to be anappreciable fraction
42、of the material thickness (Note 5). 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. Therefo
43、re, for a given specimen, 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 fromth
44、e first exposure. Indications 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
45、, cautionshould be used 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 5Mottling is often associated with th
46、in sections of austeniticsteels, and copper base alloys such as copper nickel, tin bronzes, andnickel copper.8.10 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 shrinka
47、ge, all surfaces in the 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, it shall be considered to be shrinkage.8.11 The radiographic de
48、nsity of discontinuities 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.9. Keywords9.1 castings; discontinuities; gamma ray; reference radio-graphs; steel; x-
49、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 expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for re
