1、Designation: E155 10Standard Reference Radiographs forInspection of Aluminum and Magnesium Castings1This standard is issued under the fixed designation E155; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.These Reference Radiographs have been developed in cooperation with the Quality Control Committee and Aerospace Research andTesting Committee o
3、f the Aerospace Industries Association.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These reference radiographs illustrate the types anddegrees of discontinuities that may be found in aluminum-alloyand magnesium-alloy castings. The castings illustrated
4、 are inthicknesses of14 in. (6.35 mm) and34 in. (19.1 mm). Thereference radiograph films are an adjunct to this document andmust be purchased separately from ASTM International ifneeded.1.2 These film reference radiographs are not intended toillustrate the types and degrees of discontinuities found
5、inaluminum-alloy castings when performing digital radiography.If performing digital radiography of aluminum-alloy castings,refer to Digital Reference Image Standard E2422. Magnesium-alloy digital reference images are not currently available fromASTM International.1.3 This document may be used where
6、no other applicabledocument exists, for other material thicknesses for which it hasbeen found to be applicable and for which agreement has beenreached between the purchaser and the manufacturer.1.4 The values stated in inch-pound units are to be regardedas the standard. The values given in parenthes
7、es are mathemati-cal conversions to SI units that are provided for informationonly and are not considered standard.1.5 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
8、safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1Vol I: The set of reference radiographs consists of 13 platescovering discontinuities in aluminum-alloy castings and 10 plates cover-ing discontinuities in magnesium-alloy castings. Each plate i
9、s held in an812 by 11-in. (216 by 279-mm) cardboard frame and each plate illustrateseight grades of severity for the discontinuity in approximatelya2by2-in.(51 by 51-mm) area. The cardboard frames are contained in a 1012 by1112-in. (267 by 292-mm) ring binder. The reference radiographs are notimpact
10、ed by this revision. There have been no revisions to the adjunctreference radiographs since original issue. The adjunct reference radio-graphs of any issue remain valid and may be used to this standard.Vol. II: The set of reference radiographs consists of four plates coveringdiscontinuities in magne
11、sium-alloy castings only. Each plate is held in an812 by 11-in. (216 by 279-mm) cardboard frame and illustrates eightgrades of severity for the discontinuity (with the exception of discretediscontinuities, where only one example of each discontinuity is given).NOTE 2Reference radiographs applicable
12、to aluminum and magne-sium die castings up to 1 in. (25 mm) in thickness are contained inReference Radiographs E505.2. Referenced Documents2.1 ASTM Standards:2E94 Guide for Radiographic ExaminationE505 Reference Radiographs for Inspection of Aluminumand Magnesium Die CastingsE1316 Terminology for No
13、ndestructive ExaminationsE2422 Digital Reference Images for Inspection of Alumi-num Castings2.2 ASTM Adjuncts:Reference Radiographs for Inspection of Aluminum andMagnesium Castings:Volume I, Aluminum and Magnesium Castings3Volume II, Magnesium Castings43. Terminology3.1 DefinitionsDefinitions of ter
14、ms used in this standardmay be found in Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 The terms relating to discontinuities used in thesereference radiographs are described based upon radiographicappearance.1These reference radiographs are under the jurisdiction of ASTM
15、CommitteeE07 on Nondestructive Testing and are the direct responsibility of SubcommitteeE07.02 on Reference Radiological Images.Current edition approved Sept. 1, 2010. Published September 2010. Originallyapproved in 1960. Last previous edition approved in 2005 as E155 - 05. DOI:10.1520/E0155-10.2For
16、 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.3Available from ASTM International Headquarters. Order Reference
17、Radio-graph No. RRE015501.4Available from ASTM International Headquarters. Order Reference Radio-graph No. RRE015502.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.2 foreign materialsappear as isolated, irregular, orelongated va
18、riations of film density, not corresponding tovariations in thickness of material, nor to cavities. They may bedue to the presence of sand, slag, oxide or dross, or metal ofdifferent density.3.2.3 gas holesappear as round or elongated, smooth-edged dark spots, occurring individually, in clusters, or
19、 distrib-uted throughout the casting.3.2.4 gas porosityrepresented by round or elongated darkspots corresponding to minute voids usually distributedthrough the entire casting.3.2.5 microshrinkage (feathery type)microshrinkage hav-ing an elongated appearance resembling feather-like streaks.3.2.6 micr
20、oshrinkage (sponge type)microshrinkage hav-ing a spongelike appearance, and more massive and equiaxedthan the feathery type.3.2.7 reacted sand inclusionsappear on radiograph as“spotty segregation,” that is, sharply defined round light areas,about 1 mm in diameter, and often with the rim lighter than
21、 thecenter. They are entrapped sand particles that underwentreaction with molten magnesium alloys containing zirconium(Note 3).3.2.8 segregationsappear as variations in film densitywhich can be explained by segregation of elements of atomicnumbers different from that of the matrix.3.2.8.1 gravity se
22、gregationappears white on radiographand may range from a mottling-type effect through white-diffused spots blending with the matrix, to a cloud-likeappearance in more severe cases. They are agglomerations ofparticles precipitated at temperatures above liquidus (Note 3).3.2.8.2 eutectic segregationty
23、pe of segregation is gener-ally represented when a defect or discontinuity develops duringsolidification and is fed with a near eutectic residual liquid richwith alloying elements that have a high X-ray attenuation. Oneexception to this enrichment as illustrated in Reference Radio-graphs E155 is flo
24、w line (or eutectic depletion), where there isa local impoverishment of the alloying elements that have ahigh X-ray attenuation (Note 3).(1) eutectic segregationmicroshrinkage typetype of seg-regation develops when a microshrinkage develops duringsolidification, and is fed with residual liquid rich
25、in densealloying elements such as thorium. The area will show light ona radiograph (Note 3).(2) eutectic segregationpipe-shrink typetype of segre-gation develops during solidification when a pipe shrink formsand is immediately filled with eutectic liquid rich in high X-rayattenuation alloying elemen
26、ts. The area shows light on aradiograph as a feathery or dendritic feature (Note 3).(3) eutectic segregationhot-tear typetype of segregationdevelops during solidification when the hot tear that takes placeis immediately filled with liquid rich in alloying elements highin X-ray attenuation. The defec
27、t shows as white or lightirregular defined lines (Note 3).(4) eutectic depletionflow linetype of segregation devel-ops when a section of a mold is filled by liquid and solidifiesat the front before liquid from another feed meets the solidfront. A portion of the solid front then partially melts; othe
28、r-wise, the discontinuity would be a cold shut. Solidificationbegins after this remelt and the initial crystals are of high purityand contain fewer high-density alloying elements than the meltaverage. Since the metal is still flowing across these crystals,the composition ahead of this solidifying fr
29、ont is depleted. Thisdepletion of the eutectic shows on the radiograph as a darkdiffused line (Note 3).(5) oxide inclusions in magnesium alloys containingzirconiumshow on a radiograph as well defined light area ofirregular shape and size resembling a radiograph of a com-pacted fine steel wool. It is
30、 composed of complex magnesiumoxide film with high zirconium content, and, if present, rareearths and thorium oxides also. It is often associated withzirconium-rich particles.NOTE 3More detailed descriptions of these discontinuities can befound in the article, “New Reference Radiographs for Magnesiu
31、m AlloyCastings,” by B. Lagowski, published in the Journal of Testing andEvaluation, Vol 2, No. 4, July 1974.3.2.9 shrinkage cavityappears as a dendritic, filamentary,or jagged darkened area.3.2.10 shrinkage porosity or sponge (nonferrous alloys)alocalized lacy or honeycombed darkened area.4. Signif
32、icance and Use4.1 These radiographs are intended for reference only butare so designed that acceptance standards, which may bedeveloped for particular requirements, can be specified interms of these radiographs. The illustrations are radiographs ofcastings that were produced under conditions designe
33、d todevelop the discontinuities. The radiographs of the14-in.(6.35-mm) castings are intended to be used in the thicknessrange up to and including12 in. (12.7 mm). The radiographs ofthe34-in. (19.1-mm) castings are intended to be used in thethickness range of over12 in. to and including 2 in. (51 mm)
34、.The grouping and system of designations are based on consid-erations of the best practical means of making these referenceradiographs of the greatest possible value.4.2 Film DeteriorationRadiographic films are subject towear and tear from handling and use. The extent to which theimage deteriorates
35、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 examined for signs of wear and tear, includingscratches, abrasions, sta
36、ins, 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.5. Basis for Application5.1 The reference radiographs may be applied as acceptancestandards tailored to the end use of the pr
37、oduct. Application ofthese reference radiographs as acceptance standards should bebased on the intended use of the product and the followingconsiderations (see Note 4).5.1.1 Compare the production radiographs of the castingsubmitted for evaluation with the reference radiographs appli-cable to design
38、ated wall thickness in accordance with thewritten acceptance criteria.E155 1025.1.2 An area of like size to that of the reference radiographshall be the unit area by which the production radiograph isevaluated, and any such area shall meet the requirements asdefined for acceptability.5.1.3 Any combi
39、nation or portion of these reference radio-graphs may be used as is relevant to the particular application.Different grades or acceptance limits may be specified for eachdiscontinuity type. Furthermore, different grades may be speci-fied for different regions or zones of a component.5.1.4 Special co
40、nsiderations may be required where morethan one discontinuity type is present in the same area. Anymodifications to the acceptance criteria required on the basis ofmultiple discontinuity types must be specified.5.1.5 Where the reference radiographs provide only anungraded illustration of a discontin
41、uity, acceptance criteriamay be specified by referencing a maximum discontinuity size,or percentage of the discontinuity size illustrated.5.1.6 Production radiographs showing porosity, gas, shrink-age, or inclusions shall be evaluated by the overall conditionwith regard to size, number, and distribu
42、tion. The aggregatesize of discontinuities shall not exceed the total accumulationin area of the discontinuities of the reference radiograph. It isnot the intent that the maximum size of the illustrated discon-tinuity shall be the limiting size for a single productionradiographic discontinuity, or t
43、hat the number of discontinui-ties shown on the reference radiograph shall be the limitingnumber for production radiographs. Also, caution should beexercised in judging a large discontinuity against a collectionof small discontinuities on the basis of size alone. Each of thefactors of size, number,
44、and distribution must be considered inbalance. The purchaser may provide documented specificmethods of evaluation.5.1.7 When the severity level of discontinuities per unit inthe production radiograph being evaluated is equal to or betterthan the severity level in the specified reference radiograph,t
45、hat part of the casting represented by the production radio-graph shall be acceptable. If the production radiograph showsdiscontinuities per unit area of greater severity than thereference radiograph, that part of the casting shall not beaccepted.5.1.8 As a minimum the acceptance criteria should con
46、taininformation addressing: zoning of the part (if applicable), theacceptable severity level for each discontinuity type, and thespecified area to which the reference radiographs are to beapplied.NOTE 4Caution should be exercised in specifying the acceptancecriteria to be met in a casting. Casting d
47、esign coupled with foundrypractice should be considered. It is advisable to consult with themanufacturer/foundry before establishing the acceptance criteria to ensurethe desired quality level can be achieved.6. Description6.1 The radiographs listed in Table 1 illustrate each type ofdiscontinuity in
48、eight grades. The radiographs listed in Table 2illustrate each type of discontinuity in eight grades, with theexception of pipe shrink, flow line, hot tear and oxide inclu-sion, where a single ungraded illustration is given for each.Although eight grades of each discontinuity are shown (withthe abov
49、e exceptions), a numerically smaller graded set ofdiscontinuities based on these reference radiographs could beused for acceptance standards. Each grade is illustrated inapproximatelya2by2-in. (51 by 51-mm) area. The radio-graphic technique used is in agreement with Guide E94, andproduced a desired density of 2.0 to 2.25.6.2 The alloys used to reproduce the various discontinuitieswere as listed in Table 3.NOTE 5Misruns, core shift, cold shut, and surface irregularities arenot illustrated, as they are readily identifiable by surface inspection or by
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