1、Designation: E186 10Standard Reference Radiographs forHeavy-Walled (2 to 412-in. (50.8 to 114-mm) Steel Castings1This standard is issued under the fixed designation E186; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last 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 Department of Defense.1. Scope1.1 These reference radiographs2illustrat
3、e various catego-ries, types and severity levels of discontinuities occurring insteel castings that have section thicknesses of 2 to less than 412in. (50.8 to 114 mm). The reference radiograph films are anadjunct to this document and must be purchased separatelyfrom ASTM International, if needed (se
4、e 2.2). Categories andseverity levels for each discontinuity type represented by thesereference radiographs are described in 1.2.1. Note that the basisof application for these reference radiographs requires a priorpurchaser/supplier agreement of radiographic examination at-tributes and classificatio
5、n criterion as described in Sections 4,6, and 7 of this standard. Reference radiographs for other steelcasting thicknesses may be found in Reference Radiographstandards E446 and E280. Reference Radiograph standardsE446 and E280 provide some overlap of severity levels forsimilar discontinuity categor
6、ies within the same energy levelrange (see 4.2, 5.1, and 6.3)1.2 These reference radiographs consist of three separatevolumes as follows:1.2.1 Volume I: 1MV X Rays and Iridium 192 (called “1 to2Mev X rays” in previous editions)-Set of 28 plates (nominal5 by 8 in. (127 by 203 mm) in a 15 by 17 in. (3
7、81 by 432 mm)ring binder).1.2.2 Volume II: 2MV X Rays and Cobalt-60 (called“gamma rays” in previous editions). This includes cobalt-60 orequivalent isotope radiation and from 2MV up to 4MV Xrays- Set of 28 plates (nominal 5 by 8 in.) in a 15 by 17 in. ringbinder.1.2.3 Volume III: 4MV to 30MV X rays
8、(called “10 to 24Mev X rays” in previous editions)- Set of 28 plates (nominal 5by 8 in.) in a 15 by 17 in. ring binder.1.2.4 Unless otherwise specified in a purchaser supplieragreement (see 1.1), each volume is for comparison only withproduction radiographs produced with radiation energy levelswithi
9、n the thickness range covered by this standard. Eachvolume consists of three categories of graded discontinuities inincreasing severity levels, and three categories of ungradeddiscontinuities. Reference radiographs containing ungradeddiscontinuities are provided as a guide for recognition of aspecif
10、ic casting discontinuity type where severity levels are notneeded. Following is a list of discontinuity categories, typesand severity levels for the adjunct reference radiographs of thisstandard:1.2.4.1 Category AGas porosity; severity levels 1 through5.1.2.4.2 Category BSand and slag inclusions; se
11、veritylevels 1 through 5.1.2.4.3 Category CShrinkage; three types:(1) Calinear shrinkageseverity levels 1 through 5.(Called Type 1 in previous revisions)(2) Cbfeathery shrinkageSeverity levels 1 through 5.(Called Type 2 in previous revisions)(3) Ccsponge shrinkageSeverity levels 1 through 5.(Called
12、Type 3 in previous revisions)1.2.4.4 Category DCrack; one illustration (D3 in pre-1972 documents).1.2.4.5 Category EHot tear; one illustration in pre-1972documents.1.2.4.6 Category FInsert; one illustration (EB3 in pre-1972 documents).1.3 The values stated in inch-pound units are to be regardedas th
13、e standard. SI values are shown for information 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 o
14、f regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E94 Guide for Radiographic ExaminationE242 Reference Radiographs for Appearances of Radio-graphic Images as Certain Parameters Are Changed1These reference radiographs are under the jurisdiction of ASTM CommitteeE07 on N
15、ondestructive Testing and is the direct responsibility of SubcommitteesE07.02 on Reference Radiological Images and E07.93 on Illustration Monitoring.Current edition approved Jan. 1, 2010. Published February 2010. Originallyapproved in 1962. Last previous edition approved in 2004 as E186 - 98(2004)1.
16、DOI: 10.1520/E0186-10.2For ASME Boiler and Pressure Vessel Code applications see related ReferenceRadiographs SE 186 in Section V of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vo
17、lume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.E280 Reference Radiographs for Heavy-Walled (412 to12-in. 114 to 305-mm) Steel CastingsE446 Reference R
18、adiographs for Steel Castings Up to 2 in.51 mm in ThicknessE1316 Terminology for Nondestructive Examinations2.2 ASTM Adjuncts:4Reference Radiographs for Heavy-Walled (2 to 412-in. (50.8to 114-mm) Steel Castings:Volume I, 1-MV X-Rays and Iridium-1925Volume II, 2 to 4-MV X-Rays and Cobalt-606Volume II
19、I, 4-MV to 30-MV X-Rays73. 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 discontinuity type
20、a 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” represents the
21、 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 distribut
22、ion” 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 type,c
23、ategory 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 a speci
24、fied 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-tion on
25、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 proportionately.4. Si
26、gnificance 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 provide
27、d as a guide forrecognition of a specific casting discontinuity type whereseverity levels may not be needed. These reference radiographsare intended as a basis from which manufacturers and purchas-ers may, by mutual agreement, select particular discontinuityclasses to serve as standards representing
28、 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 serviceapplic
29、ation. Severity levels of similar discontinuity categoriesand energy level range of E446 or E280 reference radiographsmay alternatively be used, as determined appropriate for thecasting service application, if so agreed upon in a purchasersupplier agreement (see Section 1 and 5.1).4.3 Procedures for
30、 evaluation 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 m
31、odifications 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 requisiteswhere weld repairs to castings may be required.5. Method of Preparation5.1 The ori
32、ginal radiographs used to prepare the adjunctreference radiographs were produced on ASTM Class I or IIfilm systems by the respective use of radiation energies statedin 1.2.1 to 1.2.3. The original radiographs were made with apenetrameter sensitivity, as determined by ASTM penetram-eters (see Guide E
33、94), of 2-2T. The adjunct reference radio-graphs are reproductions prepared to an optical density of 2.00to 2.25 and have substantially retained the contrast of theoriginal radiographs. In preparing these reference radiographs,the objective was to obtain progressively graduated severitylevels for ea
34、ch graded discontinuity category of this standard.Additionally, some overlap of severity levels may occur forsimilar discontinuity categories of Reference Radiograph stan-dard E446 or E280 with the same energy level range (see 6.3).5.2 Film DeteriorationRadiographic films are subject towear and tear
35、 from handling and use. The extent to which theimage deteriorates over time is a function 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 exami
36、ned for signs of wear and tear, includingscratches, abrasions, stains, and so forth. Any reference radio-graphs which show signs of excessive wear and tear whichcould influence the interpretation and use of the radiographsshould be replaced.4Available from ASTM Headquarters.5Order RRE018601.6Order R
37、RE018602.7Order RRE018603.E186 1026. Determination of Radiographic Classification6.1 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 appli
38、cable 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, shock,
39、 resistance to corrosion, involve-ment of penetrating radiations or radiation products, andinvolvement of dangerous gases or liquids.6.2 For each individual casting or specific area of a castingto be radiographed, the discontinuity class must be clearlyspecified. For example: severity level 2 might
40、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 7).6.3 When determining discontinuity severity levels for in-dividual castings spanning thickness ranges outside the
41、 rangeof this standard, consideration should be given to the potentialfor overlapping severity levels as described in 4.2 and 5.1.6.4 Production radiographs which are compared to refer-ence radiographs should have an optical density in the area ofinterest in accordance with Standard Guide E94 and a
42、specifiedminimum radiographic sensitivity (quality level) of 2 % (2-2T). Other radiographic quality levels or optical densities maybe designated, but then a corresponding change in severitylevel for each discontinuity category should be anticipated andhence specified.7. Classification Specifications
43、7.1 The applicable radiographic discontinuity classificationshould be designated by the contracting agency in formalspecifications or drawings and in the specific contract or order.The specifications, drawings, contract, or order should alsodesignate the sampling plan for the castings to be radiogra
44、phedand the extent of radiographic coverage, radiographic practiceto be followed (see Guide E94), image quality desired (seeNote 1), as well as the severity of acceptable discontinuity forgraded discontinuity.NOTE 1For description of sensitivity or image quality levels, seeGuide E94 and Reference Ra
45、diograph standard E242.8. Procedure for Evaluation8.1 Compare the production radiographs of the castingsubmitted for evaluation with the reference radiographs ex-posed at an equivalent energy range within the thickness rangeof this standard (unless otherwise specifiedsee Section 4).8.2 When the seve
46、rity 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 beacceptable. If the production radiograph shows discontinuitiesof grea
47、ter 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 evaluation unit area that shares a discontinuity with anadjacent unit evaluation area shall
48、 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 radiograph shall be prorated to thereference radiographic ar
49、ea.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 categories of discontinuity and that part of the castingshall be judged unacceptable.8.5 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 p
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1