【国外标准】 Standard Reference Radiographs for Ductile Iron Castings

4.1 The casting process has demonstrated radiographic similarities between internal discontinuities for ductile cast iron and cast steel to the extent that the reference radiographs for steel castings are applicable. The exact application and usage of discontinuity classifications contained within steel casting reference radiographs must, however, give consideration to the differences in material properties between cast steel and ductile cast iron. In some applications, reference radiographs for steel castings may not be entirely applicable to ductile cast iron material dependent upon design or other usage criteria.4.2 When employing steel casting reference radiographs to evaluate ductile iron castings for film radiography, the applicable E446, E186, or E280 steel casting written standard shall also be used for specific guidance and evaluation procedures. When employing digital radiographic methods, the digital reference images in Digital Reference Images E2868 and E3030 shall be used.4.3 These reference radiographs are intended as a basis from which manufacturers and purchasers may, by mutual agreement, select particular discontinuity classes to serve as standards representing minimum levels of acceptability. Reference radiographs represented by these steel casting standards may be used, as agreed upon in a purchaser supplier agreement, for radiation energy levels, thicknesses, or both, outside the range of these standards when determined applicable for the casting service application4.4 Personnel utilizing reference radiographs to this standard shall be qualified and authorized to perform radiographic interpretation in accordance with a nationally or internationally recognized NDT personnel qualification practice or standard such as ANSI/ASNT-CP-189, SNT-TC-1A, NAS 410, ISO 9712, or a similar document and certified by the employer or certifying agency, as applicable. The practice or standard used and its applicable revision shall be identified in the contractual agreement between the using parties. A certified Level III shall be available to assist with interpreting specifications and product requirements as applied to the reference radiographs (if the Level III is the radiographic interpreter, this may be the same person).1.1 This standard extends the application of steel casting Reference Radiographs E446, E186, and E280 when performing film radiography and Digital Reference Images E2868 and E3030 when performing digital radiography to ductile iron castings when determined appropriate for specific applications (see Section 4).1.2 The reference radiograph films are an adjunct to Reference Radiographs E446, E186, or E280, and must be purchased separately from ASTM International, if needed. Likewise, when performing digital radiography, the digital reference images are an adjunct to Digital Reference Images E2868 and E3030 and must be purchased separately from ASTM International, if needed (see 2.1). Categories and severity levels for each discontinuity type represented by these reference radiographs are described within each applicable standard above.NOTE 1: The basis of application for these reference radiographs requires a prior purchaser supplier agreement of radiographic examination attributes and classification criterion as described in Sections 4, 5, and 6 of this standard.1.3 From time to time, there may be minor changes to the process for manufacturing of the reference radiograph adjunct materials. These changes could include changes in the films or processing chemicals used, changes in the dies or printing for the cardboard mats, etc.; however, in all cases, these changes are reviewed by the Illustration Monitoring Subcommittee and all reference radiographs are reviewed against a fixed prototype image to ensure that there are no changes to the acceptance level represented by the reference radiographs. Therefore, the adjunct reference radiographs remain valid for use with this standard regardless of the date of production or the revision level of the text standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.