1、Designation: E1734 15Standard Practice forRadioscopic Examination of Castings1This standard is issued under the fixed designation E1734; 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 parenth
2、eses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers a uniform procedure for radio-scopic examination of castings. Radioscopic examination ofweldments can be found in E1416.1.2 This pr
3、actice applies only to radioscopic examination inwhich an image is finally presented on a display screen(monitor) for evaluation. Test part acceptance may be based ona static or dynamic image. The examination results may berecorded for later review. This practice does not apply to fullyautomated sys
4、tems in which evaluation is performed automati-cally by a computer.1.3 Due to the many complex geometries and part configu-rations inherent with castings, it is necessary to recognize thepotential limitations associated with obtaining complete radio-scopic coverage. Consideration shall be given to a
5、reas wheregeometry or part configuration does not allow for completeradioscopic coverage.1.4 The values stated in inch-pound units are to be regardedas the standard. The SI units given in parentheses are forinformation only.1.5 This standard does not purport to address all of thesafety concerns, if
6、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 Guide for Radiographic ExaminationE543 Speci
7、fication for Agencies Performing NondestructiveTestingE747 Practice for Design, Manufacture and Material Group-ing Classification of Wire Image Quality Indicators (IQI)Used for RadiologyE1000 Guide for RadioscopyE1025 Practice for Design, Manufacture, and MaterialGrouping Classification of Hole-Type
8、 Image Quality In-dicators (IQI) Used for RadiologyE1165 Test Method for Measurement of Focal Spots ofIndustrial X-Ray Tubes by Pinhole ImagingE1255 Practice for RadioscopyE1316 Terminology for Nondestructive ExaminationsE1411 Practice for Qualification of Radioscopic SystemsE1416 Test Method for Ra
9、dioscopic Examination of Weld-mentsE1453 Guide for Storage of Magnetic Tape Media thatContains Analog or Digital Radioscopic DataE1475 Guide for Data Fields for Computerized Transfer ofDigital Radiological Examination DataE1647 Practice for Determining Contrast Sensitivity in Ra-diologyE1742 Practic
10、e for Radiographic ExaminationE2002 Practice for Determining Total Image Unsharpness inRadiologyE2903 Test Method for Measurement of the Effective FocalSpot Size of Mini and Micro Focus X-ray Tubes2.2 ASNT Standards:3ASNT SNT-TC-1A Personnel Qualification and Certifica-tion in Nondestructive Testing
11、ANSI/ASNT CP-189 Personnel Qualification and Certifica-tion in Nondestructive Testing2.3 Military Standard:NAS-410 NAS Certification and Qualification of Nonde-structive Personnel (Quality Assurance Committee)43. Terminology3.1 DefinitionsDefinitions of terms applicable to thispractice may be found
12、in Terminology E1316.4. Significance and Use4.1 The requirements in this practice are intended to controlthe quality of the radioscopic images to produce satisfactory1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommi
13、ttee E07.01 onRadiology (X and Gamma) Method.Current edition approved June 1, 2015. Published July 2015. Originally approvedin 1995. Last previous edition approved in 2009 as E1734 - 09. DOI: 10.1520/E1734-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custom
14、er Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from TheAmerican Society for Nondestructive Testing (ASNT), P.O.Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518.4Available from Aerosp
15、ace Industries Association of America, Inc. 1250 EyeStreet N.W., Washington, DC 20005.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1and consistent results. This practice is not intended for con-trolling the acceptability of the cast
16、ing. The radioscopicmethod may be used for detecting volumetric discontinuitiesand density variations that are within the sensitivity range ofthis practice. The dynamic aspects of radioscopy are useful formaximizing defect response.5. Basis of Application5.1 The following items shall be agreed upon
17、between thepurchaser and the supplier:5.1.1 Nondestructive Testing Agency EvaluationIf speci-fied in the contractual agreement, nondestructive testing (NDT)agencies shall be qualified and evaluated as described inPractice E543. The applicable edition of Practice E543 shall bespecified in the contrac
18、tual agreement.5.1.2 Personnel QualificationIf specified in the contrac-tual agreement, personnel performing examinations to thisstandard shall be qualified in accordance with a nationally orinternationally recognized NDT personnel qualification prac-tice or standard such as ANSI/ANST-CP-189, SNT-TC
19、-1A,NAS-410 or similar document and certified by the employer orcertifying agency, as applicable. The practice or standard usedand its applicable revision shall be identified in the contractualagreement between the using parties.5.1.3 Recording MediaIf required, the recording media tobe used shall b
20、e specified in accordance with the requirementsof Section 6.5.1.4 Performance MeasurementsPerformance measure-ment shall be specified in accordance with the requirements ofSection 6.5.1.5 ProcedureProcedural requirements shall be speci-fied in the contractual agreement.5.1.6 RecordsRecords shall be
21、specified in the contractualagreement.6. Apparatus6.1 Success of the radioscopic process depends on theoverall system configuration and the selection of appropriatesubsystem components. Guidance on the selection of sub-system components and the overall system configuration isprovided in Guide E1000
22、and Practice E1255. Guidance on theinitial qualification and periodic re-qualification of the radio-scopic system is provided in Practice E1411. The suitability ofthe radioscopic system shall be demonstrated by attainment ofthe required image quality and compliance with all otherrequirements stipula
23、ted herein; unless otherwise specified bythe cognizant engineering organization, the default imagequality level shall be 22T.6.2 Equipment:6.2.1 Radiation Source (X-Ray or Gamma-Ray)Selectionof the appropriate source is dependent on variables regardingthe casting being examined, such as material com
24、position andthickness. Guidance on selection of the radiation source maybe found in Practice E1255.6.2.2 Manipulation SubsystemSelection of the appropriatemanipulation system (where applicable) is dependent on vari-ables such as the size and orientation of the object beingexamined and the range of m
25、otions, speed of travel, andsmoothness of motion. Guidance on selection of the manipu-lation subsystem may be found in Practice E1255.6.2.3 Detector SubsystemSelection of the appropriate de-tection system is dependent on variables such as the materialand size of the object being examined and the ene
26、rgy andintensity of the radiation used for the examination. Guidanceon selection of the detector subsystem may be found in PracticeE1255.6.2.4 Image Processing SubsystemWhere agreed uponbetween the purchaser and the supplier, image processingsystems may be used for noise reduction through imageinteg
27、ration or averaging, contrast enhancement, and otherimage processing operations. Users of digital image processingare cautioned to test image processing parameters thoroughlybefore use. For example, some spatial filter functions producedirectional results and may suppress desired image informa-tion.
28、 Other spatial filters can introduce artifacts into the image.6.2.5 Image Display SubsystemSelection of the appropri-ate image display is critical to the transfer of image informationfrom the radioscopic system to the person making the accept-reject decision. The image display should be suitably siz
29、ed andplaced in a controlled environment with subdued lighting tomaximize the transfer of image information to the radioscopicsystem operator.6.2.6 CollimationSelection of appropriate collimation isdependent on the geometry of the object being examined. It isgenerally useful to select collimation to
30、 limit the primaryradiation beam to the detector area or region of interest,whichever is smaller, thereby limiting scatter radiation in orderto improve radioscopic image quality.6.2.7 Filters and MaskingFilters and masking may beused to improve image quality by alleviating contrast reduc-tions cause
31、d by low-energy scattered radiation. Guidance onthe use of filters and masking is provided in Guide E94.6.3 Performance MeasurementRadioscopic examinationsystem performance parameters must be determined initiallyand monitored regularly to ensure consistent results. The bestmeasure of total radioscop
32、ic examination system performancecan be made with the system in operation, using a test objectsimilar to the test part under actual operating conditions. Thisindicates the use of an actual or simulated test object orcalibration block containing actual or simulated features thatmust be detected relia
33、bly. Such a calibration block will providea reliable indication of the radioscopic examination systemscapabilities. Conventional wire or plaque-type image qualityindicators (IQIs) may be used in place of, or in addition to, thesimulated test object or calibration block. Performance mea-surement meth
34、ods are subject to agreement between thepurchaser and the supplier of radioscopic examination services.6.3.1 Performance Measurement IntervalsSystem perfor-mance measurement techniques should be standardized so thatperformance measurement tests may be duplicated readily atspecified intervals. Radios
35、copic examination performanceshould be evaluated at sufficiently frequent intervals, as may beagreed upon between the purchaser and the supplier of radio-scopic examination services, in order to minimize the possi-bility of time-dependent performance variations.E1734 1526.3.2 Measurement with IQIsSy
36、stem performance mea-surements using IQIs shall be in accordance with acceptedindustry standards describing the use of IQIs. The IQIs shouldbe placed on the radiation source side of the test object, asclose as possible to the region of interest. The use of wire IQIsshould also take into account the
37、fact that the radioscopicexamination may exhibit asymmetrical sensitivity, in whichcase the wire diameter axis shall be oriented along the systemsaxis of least sensitivity. Selection of IQI thickness should beconsistent with the test part radiation path length.6.3.3 Measurement With a Calibration Bl
38、ockThe calibra-tion block may be an actual test part with known features thatare representative of the range of features to be detected, or itmay be fabricated to simulate the test object with a suitablerange of representative features. Alternatively, the calibrationblock may be a one-of-a-kind or f
39、ew-of-a-kind reference testobject containing known imperfections that have been verifiedindependently. Calibration blocks containing known, naturaldefects are useful on a single-task basis, but they are notuniversally applicable. A duplicate manufactured calibrationblock should be used where standar
40、dization among two ormore radioscopic examination systems is required. The cali-bration blocks should approximate the test object as closely asis practical, being made of the same material with similardimensions and features in the radioscopic examination regionof interest. Manufactured calibration
41、blocks shall includefeatures at least as small as those that must be detected reliablyin the actual test object in locations where they are expected tooccur. It is permissible to produce the calibration block insections where features are internal to the test object. Calibra-tion block details are a
42、 matter of agreement between thepurchaser and the supplier of radioscopic examination services.6.3.3.1 Use of a Calibration BlockThe calibration blockshall be placed in the radioscopic examination system in thesame position as the actual test object. The calibration blockmay be manipulated through t
43、he same range of motions as areavailable for the actual test object so as to maximize theradioscopic examination systems response to the simulatedimperfections.6.3.3.2 Radioscopic Examination TechniquesTechniquesused for the calibration block shall be identical to those usedfor actual examination of
44、 the test part. Technique parametersshall be listed and include, as a minimum, radiation beamenergy, intensity, focal spot size, enlargement, digital imageprocessing parameters, manipulation scan plan, and scanningspeed.6.3.4 Use of Calibrated Line Pair Test Pattern and StepWedgeA calibrated line pa
45、ir test pattern and step wedge maybe used, if desired, to determine and track the radioscopicsystem performance in terms of unsharpness and contrastsensitivity. The line pair test pattern is used without anadditional absorber to evaluate system unsharpness (see Prac-tices E1411 and E2002).The step w
46、edge is used to evaluatesystem contrast sensitivity (see Practice E1647).6.3.4.1 The step wedge must be made of the same materialas the test part, with steps representing 100, 99, 98, 97, and96 % of both the thickest and thinnest material sections to beexamined. The thinner steps shall be adjacent t
47、o the 100 %thickness in order to facilitate discerning the minimum visiblethickness step. Other thickness steps are permissible uponagreement between the purchaser and the supplier of radio-scopic examination services.6.3.4.2 The line pair test pattern and step wedge tests shallbe conducted in a man
48、ner similar to the performance measure-ments for the IQI or calibration block. It is permissible toadjust the X-ray energy and intensity to obtain a usable linepair test pattern image brightness. In the case of a radioisotopeor X-ray generating system in which the energy or intensitycannot be adjust
49、ed, additional filtration may be added to reducethe brightness to a useful level. Contrast sensitivity shall beevaluated at the same energy and intensity levels as are usedfor the radioscopic technique.6.3.4.3 A system that exhibits a thin section contrast sensi-tivity of 3 %, a thick section contrast sensitivity of 2 %, and aunsharpness of 3 line pairs/mm may be said to have a qualitylevel of 3%2%3lp/mm. A conversion table from duplexwire read out to lp/mm can be found in E1411 or E1255.6.3.4.4 The line pair test pattern and step wedge may beused to make mo
