ASTM E94-2004 Standard Guide for Radiographic Examination《放射性检查的标准指南》.pdf

1、Designation: E 94 04Standard Guide forRadiographic Examination1This standard is issued under the fixed designation E 94; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the

2、 year of last reapproval.Asuperscriptepsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide2covers satisfactory X-ray and gamma-rayradiographic examination as applied to industrial radiographicfilm recording. It includes statements about preferred prac

3、ticewithout discussing the technical background which justifies thepreference. A bibliography of several textbooks and standarddocuments of other societies is included for additional infor-mation on the subject.1.2 This guide covers types of materials to be examined;radiographic examination techniqu

4、es and production methods;radiographic film selection, processing, viewing, and storage;maintenance of inspection records; and a list of availablereference radiograph documents.NOTE 1Further information is contained in Guide E 999, PracticeE 1025, Test Methods E 1030 and E 1032.1.3 Interpretation an

5、d Acceptance StandardsInterpretation and acceptance standards are not covered by thisguide, beyond listing the available reference radiograph docu-ments for castings and welds. Designation of accept - rejectstandards is recognized to be within the cognizance of productspecifications and generally a

6、matter of contractual agreementbetween producer and purchaser.1.4 Safety PracticesProblems of personnel protectionagainst X rays and gamma rays are not covered by thisdocument. For information on this important aspect of radiog-raphy, reference should be made to the current document of theNational C

7、ommittee on Radiation Protection and Measure-ment, Federal Register, U.S. Energy Research and Develop-ment Administration, National Bureau of Standards, and tostate and local regulations, if such exist. For specific radiationsafety information refer to NIST Handbook ANSI 43.3, 21CFR 1020.40, and 29

8、CFR 1910.1096 or state regulations foragreement states.1.5 This standard does not purport to address all of thesafety problems, 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

9、 of regulatory limitations prior to use. (See 1.4.)1.6 If an NDT agency is used, the agency shall be qualifiedin accordance with Practice E 543.2. Referenced Documents2.1 ASTM Standards:3E 543 Practice for Evaluating Agencies that Perform Non-destructive TestingE 746 Test Method for Determining Rela

10、tive Image QualityResponse of Industrial Radiographic Film SystemsE 747 Practice for Design, Manufacture, and MaterialGrouping Classification of Wire Image Quality Indicators(IQI) Used for RadiologyE 801 Practice for Controlling Quality of Radiological Ex-amination of Electronic DevicesE 999 Guide f

11、or Controlling the Quality of Industrial Ra-diographic Film ProcessingE 1025 Practice for Design, Manufacture, and MaterialGrouping Classification of Hole-Type Image Quality Indi-cators (IQI) Used for RadiologyE 1030 Test Method for Radiographic Examination of Me-tallic CastingsE 1032 Test Method fo

12、r Radiographic Examination ofWeldmentsE 1079 Practice for Calibration of Transmission Densitom-etersE 1254 Guide for Storage of Radiographs and UnexposedIndustrial Radiographic FilmsE 1316 Terminology for Nondestructive ExaminationsE 1390 Guide for Illuminators Used for Viewing IndustrialRadiographs

13、E 1735 Test Method for Determining Relative Image Qual-ity of Industrial Radiographic Film Exposed toX-Radiation from 4 to 25 MVE 1742 Practice for Radiographic ExaminationE 1815 Test Method for Classification of Film Systems forIndustrial Radiography2.2 ANSI Standards:1This guide is under the juris

14、diction of ASTM Committee E07 on Nondestruc-tive Testing and is the direct responsibility of Subcommittee E07.01 on Radiology(X and Gamma) Method.Current edition approved January 1, 2004. Published February 2004. Originallyapproved in 1952. Last previous edition approved in 2000 as E 94 - 00.2For AS

15、ME Boiler and Pressure Vessel Code applications see related GuideSE-94 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 volume information, refer to the standards Docum

16、ent Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.PH1.41 Specifications for Photographic Film for ArchivalRecords, Silver-Gelatin Type, on Polyester Base4PH2.22 Methods for Determining Safety Times o

17、f Photo-graphic Darkroom Illumination4PH4.8 Methylene Blue Method for Measuring Thiosulfateand Silver Densitometric Method for Measuring ResidualChemicals in Films, Plates, and Papers4T9.1 Imaging Media (Film)Silver-Gelatin Type Specifi-cations for Stability4T9.2 Imaging MediaPhotographic Process Fi

18、lm Plate andPaper Filing Enclosures and Storage Containers42.3 Federal Standards:Title 21, Code of Federal Regulations (CFR) 1020.40,Safety Requirements of Cabinet X-Ray Systems5Title 29, Code of Federal Regulations (CFR) 1910.96,Ionizing Radiation (X-Rays, RF, etc.)52.4 Other Document:NBS Handbook

19、ANSI N43.3 General Radiation SafetyInstallations Using NonMedical X-Ray and SealedGamma Sources up to 10 MeV63. Terminology3.1 DefinitionsFor definitions of terms used in this guide,refer to Terminology E 1316.4. Significance and Use4.1 Within the present state of the radiographic art, thisguide is

20、generally applicable to available materials, processes,and techniques where industrial radiographic films are used asthe recording media.4.2 LimitationsThis guide does not take into consider-ation special benefits and limitations resulting from the use ofnonfilm recording media or readouts such as p

21、aper, tapes,xeroradiography, fluoroscopy, and electronic image intensifi-cation devices. Although reference is made to documents thatmay be used in the identification and grading, where appli-cable, of representative discontinuities in common metal cast-ings and welds, no attempt has been made to se

22、t standards ofacceptance for any material or production process. Radiogra-phy will be consistent in sensitivity and resolution only if theeffect of all details of techniques, such as geometry, film,filtration, viewing, etc., is obtained and maintained.5. Quality of Radiographs5.1 To obtain quality r

23、adiographs, it is necessary to consideras a minimum the following list of items. Detailed informationon each item is further described in this guide.5.1.1 Radiation source (X-ray or gamma),5.1.2 Voltage selection (X-ray),5.1.3 Source size (X-ray or gamma),5.1.4 Ways and means to eliminate scattered

24、radiation,5.1.5 Film system class,5.1.6 Source to film distance,5.1.7 Image quality indicators (IQIs),5.1.8 Screens and filters,5.1.9 Geometry of part or component configuration,5.1.10 Identification and location markers, and5.1.11 Radiographic quality level.6. Radiographic Quality Level6.1 Informat

25、ion on the design and manufacture of imagequality indicators (IQIs) can be found in Practices E 747,E 801, E 1025, and E 1742.6.2 The quality level usually required for radiography is2 % (2-2T when using hole type IQI) unless a higher or lowerquality is agreed upon between the purchaser and the supp

26、lier.At the 2 % subject contrast level, three quality levels ofinspection, 2-1T, 2-2T, and 2-4T, are available through thedesign and application of the IQI (Practice E 1025, Table 1).Other levels of inspection are available in Practice E 1025Table 1. The level of inspection specified should be based

27、 onthe service requirements of the product. Great care should betaken in specifying quality levels 2-1T, 1-1T, and 1-2T by firstdetermining that these quality levels can be maintained inproduction radiography.NOTE 2The first number of the quality level designation refers to IQIthickness expressed as

28、 a percentage of specimen thickness; the secondnumber refers to the diameter of the IQI hole that must be visible on theradiograph, expressed as a multiple of penetrameter thickness, T.6.3 If IQIs of material radiographically similar to that beingexamined are not available, IQIs of the required dime

29、nsionsbut of a lower-absorption material may be used.6.4 The quality level required using wire IQIs shall beequivalent to the 2-2T level of Practice E 1025 unless a higheror lower quality level is agreed upon between purchaser andsupplier. Table 4 of Practice E 747 gives a list of varioushole-type I

30、QIs and the diameter of the wires of correspondingEPS with the applicable 1T, 2T, and 4T holes in the plaque IQI.Appendix X1 of Practice E 747 gives the equation for calcu-lating other equivalencies, if needed.7. Energy Selection7.1 X-ray energy affects image quality. In general, the lowerthe energy

31、 of the source utilized the higher the achievableradiographic contrast, however, other variables such as geom-etry and scatter conditions may override the potential advan-tage of higher contrast. For a particular energy, a range ofthicknesses which are a multiple of the half value layer, may beradio

32、graphed to an acceptable quality level utilizing a particu-lar X-ray machine or gamma ray source. In all cases thespecified IQI (penetrameter) quality level must be shown onthe radiograph. In general, satisfactory results can normally beobtained for X-ray energies between 100 kV to 500 kV in arange

33、between 2.5 to 10 half value layers (HVL) of materialthickness (see Table 1). This range may be extended by asmuch as a factor of 2 in some situations for X-ray energies inthe 1 to 25 MV range primarily because of reduced scatter.4Available from American National Standards Institute (ANSI), 25 W. 43

34、rd St.,4th Floor, New York, NY 10036.5Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.6Available from National Technical Information Service (NTIS), U.S. Depart-ment of Commerce, 5285 Port Royal Rd., Springfield,

35、 VA 22161.E940428. Radiographic Equivalence Factors8.1 The radiographic equivalence factor of a material is thatfactor by which the thickness of the material must be multi-plied to give the thickness of a “standard” material (often steel)which has the same absorption. Radiographic equivalencefactors

36、 of several of the more common metals are given inTable 2, with steel arbitrarily assigned a factor of 1.0. Thefactors may be used:8.1.1 To determine the practical thickness limits for radia-tion sources for materials other than steel, and8.1.2 To determine exposure factors for one metal fromexposur

37、e techniques for other metals.9. Film9.1 Various industrial radiographic film are available tomeet the needs of production radiographic work. However,definite rules on the selection of film are difficult to formulatebecause the choice depends on individual user requirements.Some user requirements ar

38、e as follows: radiographic qualitylevels, exposure times, and various cost factors. Severalmethods are available for assessing image quality levels (seeTest Method E 746, and Practices E 747 and E 801). Informa-tion about specific products can be obtained from the manu-facturers.9.2 Various industri

39、al radiographic films are manufacturedto meet quality level and production needs. Test MethodE 1815 provides a method for film manufacturer classificationof film systems. A film system consist of the film andassociated film processing system. Users may obtain a classi-fication table from the film ma

40、nufacturer for the film systemused in production radiography. A choice of film class can bemade as provided in Test Method E 1815. Additional specificdetails regarding classification of film systems is provided inTest Method E 1815. ANSI Standards PH1.41, PH4.8, T9.1,and T9.2 provide specific detail

41、s and requirements for filmmanufacturing.10. Filters10.1 DefinitionFilters are uniform layers of materialplaced between the radiation source and the film.10.2 PurposeThe purpose of filters is to absorb the softercomponents of the primary radiation, thus resulting in one orseveral of the following pr

42、actical advantages:10.2.1 Decreasing scattered radiation, thus increasing con-trast.10.2.2 Decreasing undercutting, thus increasing contrast.10.2.3 Decreasing contrast of parts of varying thickness.10.3 LocationUsually the filter will be placed in one ofthe following two locations:10.3.1 As close as

43、 possible to the radiation source, whichminimizes the size of the filter and also the contribution of thefilter itself to scattered radiation to the film.10.3.2 Between the specimen and the film in order to absorbpreferentially the scattered radiation from the specimen. Itshould be noted that lead f

44、oil and other metallic screens (see13.1) fulfill this function.10.4 Thickness and Filter Material The thickness andmaterial of the filter will vary depending upon the following:10.4.1 The material radiographed.10.4.2 Thickness of the material radiographed.10.4.3 Variation of thickness of the materia

45、l radiographed.10.4.4 Energy spectrum of the radiation used.10.4.5 The improvement desired (increasing or decreasingcontrast). Filter thickness and material can be calculated ordetermined empirically.11. Masking11.1 Masking or blocking (surrounding specimens or cov-ering thin sections with an absorp

46、tive material) is helpful inreducing scattered radiation. Such a material can also be usedTABLE 1 Typical Steel HVL Thickness in Inches mm forCommon EnergiesEnergyThickness,Inches mm120 kV 0.10 2.5150 kV 0.14 3.6200 kV 0.20 5.1250 kV 0.25 6.4400 kV (Ir 192) 0.35 8.91 MV 0.57 14.52 MV (Co 60) 0.80 20

47、.34 MV 1.00 25.46 MV 1.15 29.210 MV 1.25 31.816 MV and higher 1.30 33.0TABLE 2 Approximate Radiographic Equivalence Factors for Several Metals (Relative to Steel)MetalEnergy Level100 kV 150 kV 220 kV 250 kV 400 kV 1 MV 2 MV 4 to 25 MV192Ir60CoMagnesium 0.05 0.05 0.08Aluminum 0.08 0.12 0.18 0.35 0.35

48、Aluminum alloy 0.10 0.14 0.18 0.35 0.35Titanium 0.54 0.54 0.71 0.9 0.9 0.9 0.9 0.9Iron/all steels 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0Copper 1.5 1.6 1.4 1.4 1.4 1.1 1.1 1.2 1.1 1.1Zinc 1.4 1.3 1.3 1.2 1.1 1.0Brass 1.4 1.3 1.3 1.2 1.1 1.0 1.1 1.0Inconel X 1.4 1.3 1.3 1.3 1.3 1.3 1.3 1.3Monel 1.7 1

49、.2Zirconium 2.4 2.3 2.0 1.7 1.5 1.0 1.0 1.0 1.2 1.0Lead 14.0 14.0 12.0 5.0 2.5 2.7 4.0 2.3Hafnium 14.0 12.0 9.0 3.0Uranium 20.0 16.0 12.0 4.0 3.9 12.6 3.4E94043to equalize the absorption of different sections, but the loss ofdetail may be high in the thinner sections.12. Back-Scatter Protection12.1 Effects of back-scattered radiation can be reduced byconfining the radiation beam to the smallest practical crosssection and by placing lead behind the film. In some caseseither or both the back lead screen and the lead contained in theback of the