ASTM E1734-2009 Standard Practice for Radioscopic Examination of Castings《铸件射线检验标准实施规程》.pdf

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1、Designation: E 1734 09Standard Practice forRadioscopic Examination of Castings1This standard is issued under the fixed designation E 1734; 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 paren

2、theses 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.1.2 This practice applies only to radioscopic examination inwhich an

3、 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 systems in which evaluation is performed automati-cally by a

4、 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 areas wheregeometry or part configuration does not allow f

5、or 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 any, associated with its use. It is theresponsibility of

6、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 ExaminationE 543 Specification for Agencies Performing Nondestruc-tive Testing

7、E 747 Practice for Design, Manufacture and MaterialGrouping Classification of Wire Image Quality Indicators(IQI) Used for RadiologyE 1000 Guide for RadioscopyE 1025 Practice for Design, Manufacture, and MaterialGrouping Classification of Hole-Type Image Quality Indi-cators (IQI) Used for RadiologyE

8、1255 Practice for RadioscopyE 1316 Terminology for Nondestructive ExaminationsE 1411 Practice for Qualification of Radioscopic SystemsE 1453 Guide for Storage of Magnetic Tape Media thatContains Analog or Digital Radioscopic DataE 1475 Guide for Data Fields for Computerized Transfer ofDigital Radiol

9、ogical Examination DataE 1647 Practice for Determining Contrast Sensitivity inRadiologyE 1742 Practice for Radiographic ExaminationE 2002 Practice for Determining Total Image Unsharpnessin Radiology2.2 ASNT Standards:3ASNT SNT-TC-1A Personnel Qualification and Certifica-tion in Nondestructive Testin

10、gANSI/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

11、 in Terminology E 1316.4. Significance and Use4.1 The requirements in this practice are intended to controlthe quality of the radioscopic images to produce satisfactoryand consistent results. This practice is not intended for con-trolling the acceptability of the casting. The radioscopicmethod may b

12、e 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 between thepurchaser and the sup

13、plier:1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.01 onRadiology (X and Gamma) Method.Current edition approved July 1, 2009. Published August 2009. Originallyapproved in 1995. Last previous edition app

14、roved in 2004 as E 1734 - 04.2For 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.3Available from TheAmerican Soci

15、ety for Nondestructive Testing (ASNT), P.O.Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518.4Available from Aerospace Industries Association of America, Inc. 1250 EyeStreet N.W., Washington, DC 20005.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428

16、-2959, United States.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 E 543. The applicable edition of Practice E 543 shallbe specified in the contractual agreement.

17、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-1A,NAS-410 or

18、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 be specified in

19、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 specified in th

20、e 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 E 1000 and Practice E

21、 1255. Guidance onthe initial qualification and periodic re-qualification of theradioscopic system is provided in Practice E 1411. The suit-ability of the radioscopic system shall be demonstrated byattainment of the required image quality and compliance withall other requirements stipulated herein.6

22、.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 composition andthickness. Guidance on selection of the radiation source maybe found in Practice E 1255.6.2.2 Manipulation Subsyst

23、emSelection of the appropri-ate manipulation system (where applicable) is dependent onvariables such as the size and orientation of the object beingexamined and the range of motions, speed of travel, andsmoothness of motion. Guidance on selection of the manipu-lation subsystem may be found in Practi

24、ce E 1255.6.2.3 Detector SubsystemSelection of the appropriate de-tection system is dependent on variables such as the materialand size of the object being examined and the energy andintensity of the radiation used for the examination. Guidanceon selection of the detector subsystem may be found in P

25、racticeE 1255.6.2.4 Image Processing SubsystemWhere agreed uponbetween the purchaser and the supplier, image processingsystems may be used for noise reduction through imageintegration or averaging, contrast enhancement, and otherimage processing operations. Users of digital image processingare cauti

26、oned to test image processing parameters thoroughlybefore use. For example, some spatial filter functions producedirectional results and may suppress desired image informa-tion. Other spatial filters can introduce artifacts into the image.6.2.5 Image Display SubsystemSelection of the appropri-ate im

27、age 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 sized andplaced in a controlled environment with subdued lighting tomaximize the transfer of image information to the radiosco

28、picsystem operator.6.2.6 CollimationSelection of appropriate collimation isdependent on the geometry of the object being examined. It isgenerally useful to select collimation to limit the primaryradiation beam to the detector area or region of interest,whichever is smaller, thereby limiting scatter

29、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 caused by low-energy scattered radiation. Guidance onthe use of filters and masking is provided in Guide E94.6.3 Performance Mea

30、surementRadioscopic examinationsystem performance parameters must be determined initiallyand monitored regularly to ensure consistent results. The bestmeasure of total radioscopic examination system performancecan be made with the system in operation, using a test objectsimilar to the test part unde

31、r actual operating conditions. Thisindicates the use of an actual or simulated test object orcalibration block containing actual or simulated features thatmust be detected reliably. Such a calibration block will providea reliable indication of the radioscopic examination systemscapabilities. Convent

32、ional 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 methods are subject to agreement between thepurchaser and the supplier of radioscopic examination services.6.3.1 Performance Me

33、asurement IntervalsSystem perfor-mance measurement techniques should be standardized so thatperformance measurement tests may be duplicated readily atspecified intervals. Radioscopic examination performanceshould be evaluated at sufficiently frequent intervals, as may beagreed upon between the purch

34、aser and the supplier of radio-scopic examination services, in order to minimize the possi-bility of time-dependent performance variations.6.3.2 Measurement with IQIsSystem performance mea-surements using IQIs shall be in accordance with acceptedindustry standards describing the use of IQIs. The IQI

35、s 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 fact that the radioscopicexamination may exhibit asymmetrical sensitivity, in whichcase the wire diameter axis shall be oriented alo

36、ng 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 BlockThe calibra-tion block may be an actual test part with known features thatare representative of the range of features to be detec

37、ted, or itmay be fabricated to simulate the test object with a suitableE1734092range of representative features. Alternatively, the calibrationblock may be a one-of-a-kind or few-of-a-kind reference testobject containing known imperfections that have been verifiedindependently. Calibration blocks co

38、ntaining known, naturaldefects are useful on a single-task basis, but they are notuniversally applicable. A duplicate manufactured calibrationblock should be used where standardization among two ormore radioscopic examination systems is required. The cali-bration blocks should approximate the test o

39、bject as closely asis practical, being made of the same material with similardimensions and features in the radioscopic examination regionof interest. Manufactured calibration blocks shall includefeatures at least as small as those that must be detected reliablyin the actual test object in locations

40、 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 matter of agreement between thepurchaser and the supplier of radioscopic examination services.6.3.3.1 Use of a Calibration

41、BlockThe calibration blockshall be placed in the radioscopic examination system in thesame position as the actual test object. The calibration blockmay be manipulated through the same range of motions as areavailable for the actual test object so as to maximize theradioscopic examination systems res

42、ponse to the simulatedimperfections.6.3.3.2 Radioscopic Examination TechniquesTechniquesused for the calibration block shall be identical to those usedfor actual examination of the test part. Technique parametersshall be listed and include, as a minimum, radiation beamenergy, intensity, focal spot s

43、ize, enlargement, digital imageprocessing parameters, manipulation scan plan, and scanningspeed.6.3.4 Use of Calibrated Line Pair Test Pattern and StepWedgeAcalibrated line pair test pattern and step wedge maybe used, if desired, to determine and track the radioscopicsystem performance in terms of s

44、patial resolution and contrastsensitivity. The line pair test pattern is used without anadditional absorber to evaluate system spatial resolution (seePractices E 1411 and E 2002).The step wedge is used toevaluate system contrast sensitivity (see Practice E 1647).6.3.4.1 The step wedge must be made o

45、f 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 to the 100 %thickness in order to facilitate discerning the minimum visiblethickness step. Other thickness step

46、s 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 manner similar to the performance measure-ments for the IQI or calibration block. It is permissible toadjust the

47、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 adjusted, additional filtration may be added to reducethe brightness to a useful level. Contrast sensitivity shall b

48、eevaluated 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 aspatial resolution of 3 line pairs/mm may be said to have aquality level of 3%2%3l

49、p/mm.6.3.4.4 The line pair test pattern and step wedge may beused to make more frequent periodic system performancechecks than are required in 6.3.1. Resolution and contrastsensitivity checks must be correlated with IQI or calibrationblock performance measurements. This may be accomplishedby first evaluating the system performance in accordance with6.3.2 or 6.3.3 and immediately thereafter determining theequivalent spatial resolution and contrast sensitivity values.6.4 Location and Identification MarkersLead numbersand letters may be used to designate the par