Designation:E186–10
Standard Reference Radiographs for
Heavy-Walled(2to41⁄2-in.(50.8to114-mm))Steel Castings1 This standard is issued under thefixed designation E186;the number immediately following the designation indicates the year of original adoption or,in the ca of revision,the year of last revision.A number in parenthes indicates the year of last reapproval.A superscript epsilon(´)indicates an editorial change since the last revision or reapproval.
This standard has been approved for u by agencies of the Department of Defen.
1.Scope
1.1The reference radiographs2illustrate various catego-ries,types and verity levels of discontinuities occurring in steel castings that have ction thickness of2to less than41⁄2 in.(50.8to114mm).The reference radiographfilms are an adjunct to this document and must be purchad parately from ASTM International,if needed(e
2.2).Categories and verity levels for each discontinuity type reprented by the reference radiographs are described in1.2.1.Note that the basis of application for the reference radiographs requires a prior purchar/supplier agreement of radiographic examination at-tributes and classification criterion as described in Sections4, 6,and7of this standard.Reference radiographs for other steel casting thickness may be found in Reference Radiograph standards E446and E280.Reference Radiograph standards E446and E280provide some overlap of verity levels for similar discontinuity categories within the same energy level range(e4.2,5.1,and6.3)
1.2The reference radiographs consist of three parate volumes as follows:
1.2.1V olume I:1–MV X Rays and Iridium192(called“1to 2–Mev X rays”in previous editions)-Set of28plates(nominal 5by8in.(127by203mm)in a15by17in.(381by432mm) ring binder).
1.2.2V olume II:2–MV X Rays and Cobalt-60(called “gamma rays”in previous editions).This includes
cobalt-60or equivalent isotope radiation and from2–MV up to4–MV X rays-Set of28plates(nominal5by8in.)in a15by17in.ring binder.
又一新1.2.3V olume III:4–MV to30–MV X rays(called“10to24 Mev X rays”in previous editions)-Set of28plates(nominal5 by8in.)in a15by17in.ring binder.
1.2.4Unless otherwi specified in a purchar supplier agreement(e1.1),each volume is for comparison only with production radiographs produced with radiation energy levels within the thickness range covered by this standard.Each volume consists of three categories of graded discontinuities in increasing verity levels,and three categories of ungraded discontinuities.Reference radiographs containing ungraded discontinuities are provided as a guide for recognition of a specific casting discontinuity type where verity levels are not needed.Following is a list of discontinuity categories,types and verity levels for the adjunct reference radiographs of this standard:
1.2.4.1Category A—Gas porosity;verity levels1through 5.
1.2.4.2Category B—Sand and slag inclusions;verity levels1through5.
1.2.4.3Category C—Shrinkage;three types:
(1)Ca—linear shrinkage—verity levels1through 5. (Called Type1in previous revisions)
(2)Cb—feathery shrinkage—Severity levels1through5. (Called Type2in previous revisions)
(3)Cc—sponge shrinkage—Severity levels1through5. (Called Type3in previous revisions)
1.2.4.4Category D—Crack;one illustration(D3in pre-1972documents).
1.2.4.5Category E—Hot tear;one illustration in pre-1972 documents.
run的意思1.2.4.6Category F—Inrt;one illustration(EB3in pre-1972documents).
1.3The values stated in inch-pound units are to be regarded as the standard.SI values are shown for information only. 1.4This standard does not purport to address all of the safety concerns,if any,associated with its u.It is the responsibility of the ur of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to u.
2.Referenced Documents
2.1ASTM Standards:3
E94Guide for Radiographic Examination
E242Reference Radiographs for Appearances of Radio-graphic Images as Certain Parameters Are Changed
1The reference radiographs are under the jurisdiction of ASTM Committee E07on Nondestructive Testing and is the direct responsibility of Subcommittees E07.02on Reference Radiological Images and E07.93on Illustration Monitoring.
Current edition approved Jan.1,2010.Published February2010.Originally
approved in1962.Last previous edition approved in2004as E186-98(2004)´1. DOI:10.1520/E0186-10.
2For ASME Boiler and Pressure Vesl Code applications e related Reference Radiographs SE186in Section V of that Code.
防汛预警3For referenced ASTM standards,visit the ASTM website,www.astm,or contact ASTM Customer Service at rvice@astm.For Annual Book of ASTM Standards volume information,refer to the standard’s Document Summary page on the ASTM website.
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Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.
E280Reference Radiographs for Heavy-Walled(412to 12-in.[114to305-mm])Steel Castings
E446Reference Radiographs for Steel Castings Up to2in.
[51mm]in Thickness
E1316Terminology for Nondestructive Examinations
2.2ASTM Adjuncts:4
Reference Radiographs for Heavy-Walled(2to41⁄2-in.(50.8 to114-mm))Steel Castings:
V olume I,1-MV X-Rays and Iridium-1925
V olume II,2to4-MV X-Rays and Cobalt-606
V olume III,4-MV to30-MV X-Rays7
3.Terminology
3.1Definitions—For definitions of terms relating to radio-graphic examination,e Terminology E1316.
3.2Definitions of Terms Specific to This Standard:
3.2.1production radiograph—a radiograph under review for compliance with this standard.
3.2.2discontinuity type—a specific discontinuity character-ized by its cau and appearance.For example:linear shrink-age is a specific discontinuity type.
3.2.3discontinuity category—a nomenclature system ud for grouping discontinuity types.For example:linear shrinkage is assigned category“Ca”where“C”reprents the general shrinkage category and“a”reprents the specific linear shrinkage discontinuity type.扯面怎么和面
3.2.4discontinuity verity level—a relative rank in terms of“quantity,size and distribution”of a collection of disconti-nuities where“1”is the least and“5”is the greatest“quantity, size and distribution”prent on the reference radiograph. Example:a verity level of“1”is more restrictive(requires a higher level of workmanship fabrication quality)than a ver-ity level of“2.”
3.2.5discontinuity class—an assigned workmanship fabri-cation quality rating characterized by a discontinuity type, category and verity level.For example:“Ca2”is a discon-tinuity class comprid of linear shrinkage with a verity level of“2.”
3.2.6classification specification—a t of ur defined ac-ceptance criterion that prescribes the radiographic workman-ship discontinuity class requirements for a specified ur casting rvice application(e Sections6and7).
3.2.7graded illustration—a category of discontinuity that is assigned a verity level.
3.2.8ungraded illustration—a category of discontinuity without an assigned verity level.
3.2.9prorating—assignment of quantity,size and distribu-tion on a production radiograph in proportion to a similar size area of a reference radiograph.For example:a production radiograph covers an area that is smaller than the unit area of a reference radiograph and the extent of discontinuity on the applicable reference radiograph is reduced proportionately.
4.Significance and U
4.1Graded reference radiographs are intended to provide a guide enabling recognition of specific ca
过春节作文sting discontinuity types and relative verity levels that may be encountered during typical fabrication process.Reference radiographs containing ungraded discontinuities are provided as a guide for recognition of a specific casting discontinuity type where verity levels may not be needed.The reference radiographs are intended as a basis from which manufacturers and purchas-ers may,by mutual agreement,lect particular discontinuity class to rve as standards reprenting minimum levels of acceptability(e Sections6and7).
4.2Reference radiographs reprented by this standard may be ud,as agreed upon in a purchar supplier agreement,for energy levels,thickness or both outside the range of this standard when determined applicable for the casting rvice application.Severity levels of similar discontinuity categories and energy level range of E446or E280reference radiographs may alternatively be ud,as determined appropriate for the casting rvice application,if so agreed upon in a purchar supplier agreement(e Section1and
5.1).
4.3Procedures for evaluation of production radiographs using applicable reference radiographs of this standard are prescribed in Section8;however,there may be manufacturing-purchar issues invo
lving specific casting rvice applications where it may be appropriate to modify or alter such require-ments.Where such modifications may be appropriate for the casting application,all such changes shall be specifically called-out in the purchar supplier agreement or contractual document.Section9address purchar supplier requisites where weld repairs to castings may be required.
5.Method of Preparation
5.1The original radiographs ud to prepare the adjunct reference radiographs were produced on ASTM Class I or II film systems by the respective u of radiation energies stated in1.2.1to1.2.3.The original radiographs were made with a penetrameter nsitivity,as determined by ASTM penetram-eters(e Guide E94),of2-2T.The adjunct reference radio-graphs are reproductions prepared to an optical density of2.00 to2.25and have substantially retained the contrast of the original radiographs.In preparing the reference radiographs, the objective was to obtain progressively graduated verity levels for each graded discontinuity category of this standard. Additionally,some overlap of verity levels may occur for similar discontinuity categories of Reference Radiograph stan-dard E446or E280with the same energy level range(e
6.3).
5.2Film Deterioration—Radiographicfilms are subject to wear and tear from handling and u.The extent to which the image deteriorates over time is a function of storage condi-tions,care in handling and amount of u.Reference radio-graphfilms are no exception and may exhibit a loss in image quality over time.The radiographs should therefore be peri-odically examined for signs of wear and tear,including scratches,abrasions,stains,and so forth.Any reference radio-graphs which show signs of excessive wear and tear which could influence the interpretation and u of the radiographs should be replaced.
4Available from ASTM Headquarters. 5Order RRE018601.
6Order RRE018602.
7Order RRE018603
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6.Determination of Radiographic Classification
6.1For purpos of evaluation of castings,a determination must be made of the radiographic discontinuity classifications to be assigned to individual castings or specific areas of castings.The determination of the applicable radiographic discontinuity classification shall be bad on an evaluation of the casting applications,design,and rvice requirements.In the evaluations,consideration shall be given to such factors as pressure,temperature,ction thickness,applicable design safety factor,vibration,shock,resistance to corrosion,involve-ment of penetrating radiations or radiation products,and involvement of dangerous gas or liquids.
6.2For each individual casting or specific area of a casting to be radiographed,the discontinuity class must be clearly specified.For example:verity level2might be specified for linear shrinkage,Category Ca,and verity level3for gas porosity,Category A,since the latter are generally much less deleterious to tensile properties(e Section7).
6.3When determining discontinuity verity levels for in-dividual castings spanning thickness ranges outside the range of this standard,consideration should be given to the potential for overlapping ve
rity levels as described in4.2and5.1. 6.4Production radiographs which are compared to refer-ence radiographs should have an optical density in the area of interest in accordance with Standard Guide E94and a specified minimum radiographic nsitivity(quality level)of2%(2-2T).Other radiographic quality levels or optical densities may be designated,but then a corresponding change in verity level for each discontinuity category should be anticipated and hence specified.
7.Classification Specifications
7.1The applicable radiographic discontinuity classification should be designated by the contracting agency in formal specifications or drawings and in the specific contract or order. The specifications,drawings,contract,or order should also designate the sampling plan for the castings to be radiographed and the extent of radiographic coverage,radiographic practice to be followed(e Guide E94),image quality desired(e Note1),as well as the verity of acceptable discontinuity for graded discontinuity.
N OTE1—For description of nsitivity or image quality levels,e Guide E94and Reference Radiograph standard E242.
8.Procedure for Evaluation
8.1Compare the production radiographs of the casting submitted for evaluation with the reference radiographs ex-pod at an equivalent energy range within the thickness range of this standard(unless otherwi specified—e Section4).
8.2When the verity level of discontinuities in the produc-tion radiograph being evaluated is equal to or less than the verity level in the specified reference radiograph,that part of the casting reprented by the production radiograph shall be acceptable.If the production radiograph shows discontinuities of greater verity than the reference radiograph,that part of the casting shall be rejected.
8.3A unit area on the production radiograph shall be evaluated to a unit area of like size on the reference radiograph.Any evaluation unit area that shares a discontinuity with an adjacent unit evaluation area shall meet the minimum unit area acceptability requirements within the combined unit area. When the unit area of interest of a production radiograph is less than the unit area of the applicable reference radiograph,such unit area of the production radiograph shall be prorated to the reference radiographic area.
8.4When two or more categories of discontinuity are prent in the same production radiograph,the
predominating discontinuities,if unacceptable,shall govern without regard to the other categories of discontinuity and that part of the casting shall be judged unacceptable.
8.5When two or more categories of discontinuity are prent to an extent equal to the maximum permissible level as shown in the applicable standards for each category,then that part of the casting shall be judged unacceptable.When two or more categories of discontinuity are prent in the same radiograph to an extent less than the maximum permissible level,as shown in the applicable standards for each category, the verity shall be evaluated by the overall aggregate condition.The aggregate condition is defined as the balance of quantity,size and distribution of the collection of discontinui-ties and shall not exceed the aggregate condition of the applicable reference radiograph.
8.6Reference radiographs are provided showing a variety of shrinkage discontinuity types.Production radiographs show-ing shrinkage shall be judged by the most reprentative reference radiograph.
8.7This standard does not specify limiting criteria for a single size of discontinuity,maximum number of discontinui-ties per unit area evaluated,specific dimensional spacing and/or alignment criterion between individual discontinuities or any other undefined discontinuity patterns.Unless otherwi spe
cified by a purchar supplier agreement(e Section4), the discontinuity conditions on production radiographs shall be evaluated as aggregate conditions as defined in8.5.
8.8In general,there is no limit as to the extent of acceptable discontinuities in a casting,provided that no unit evaluation area throughout the casting contains discontinuities that exceed the verity of discontinuities in the applicable reference radiographs.
8.9Reference radiographs in this standard do not illustrate elongated or“worm hole”type of gas discontinuities.When this condition occurs in a production radiograph,it shall be evaluated by comparison with the most reprentative refer-ence radiograph.
8.9.1When the exposing radiation source has been placed perpendicular to the length of the gas hole,evaluate the production radiograph with a shrinkage reference radiograph.
8.9.2When the exposing radiation source has been placed diametrically or“into”the diameter of the gas hole,evaluate the production radiograph with a gas reference radiograph. 8.10A diffraction mottling pattern can occur onfilms of parts and ctions where the grain size is large enough to be an appreciable fraction of the material thickness(e Note2).If diffraction mottling is suspected,there are a number of ways to demonstrate its prence.The diffraction mottling pattern shown in the ca
s is dependent principally upon the
crystal 3
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geometry and the orientation of the crystals to the incident radiation.Therefore,for a given specimen,any change in this orientation will affect the diffraction pattern dramatically.This can be accomplished by a slight,1to5°tilt of the part,with respect to the radiation beam or simply by shifting the center line of the radiation beam to a slightly different location from thefirst exposure.Indications from any porosity,shrinkage,or other discontinuity will move only slightly,while any mottling patterns prent will change dramatically.If it is necessary or desirable to eliminate the mottling,the kV may be raid to reduce the amount of diffraction radiation.However,caution should be ud so that the kV is not raid to the point that nsitivity is reduced excessively.If diffraction mottling is demonstrated to be prent on a radiograph,this condition shall not be considered as prejudicial in e
valuating the radiograph. N OTE2—Mottling is often associated with thin ctions of austenitic steels,and copper ba alloys such as copper nickel,tin bronzes,and nickel copper.
8.11Hot tears and cracks exhibited on production radio-graphs may at times remble linear type shrinkage.When doubt exists whether such indications are cracks or tears,or are linear shrinkage,all surfaces in the area of interest shall be ground and magnetic particle or liquid penetrant inspected as applicable.The extent and depth of grinding may require engineering judgment.If the indication does not appear on the surface,that indication shall be considered shrinkage.
8.12The radiographic density of discontinuities in compari-son with background density is a variable dependent on technical factors.It shall not be ud as a criterion for acceptance or rejection in comparison with reference radio-graphs.
9.Weld Repair of Castings夜字成语
9.1When radiographic quality castings are repaired by welding,the reference radiographs to be ud in the evaluation of the repaired ctions must be specifically agreed upon between purchar and supplier.
9.2When casting discontinuities are removed for repairs, only the extent of discontinuity required to meet applicable reference standards need be removed.
10.Keywords
10.1discontinuity classification criterion;gamma-ray;ref-erence radiographs;steel castings;X-ray
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