【国外标准】 Standard Practice for Radiographic Examination of Metallic Castings

4.1 The requirements expressed in this practice are intended to control the quality of the radiographic images, to produce satisfactory and consistent results, and are not intended for controlling the acceptability or quality of materials or products.1.1 This practice2 provides a uniform procedure for radiographic examination of metallic castings using radiographic film as the recording medium.1.2 This standard addresses the achievement of, or protocols for achieving, common or practical levels of radiographic coverage for castings, to detect primarily volumetric discontinuities to sensitivity levels measured by nominated image quality indicators. All departures, including alternate means or methods to increase coverage, or address challenges of detecting non-volumetric planar-type discontinuities, shall be agreed upon between the purchaser and supplier and shall consider Appendix X1 and Appendix X2.1.3 The radiographic techniques stated herein provide adequate assurance for defect detectability; however, it is recognized that, for special applications, specific techniques using more or less stringent requirements may be required than those specified. In these cases, the use of alternate radiographic techniques shall be as agreed upon between purchaser and supplier (also see Section 5).1.4 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.5 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.1.6 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.