【国外标准】 Standard Reference Radiographs for Inspection of Aluminum and Magnesium Die Castings

5.1 These radiographs are so designed that acceptance standards, which may be developed for particular requirements, can be specified in terms of these radiographs. The radiographs are of castings that were produced under conditions designed to produce the discontinuities. These reference radiographs are intended to be used for casting thickness ranges in accordance with Table 1.5.2 The radiographic illustrations listed in Table 1 illustrate three types of discontinuities in four severity levels. Two ungraded illustrations have been included to establish the radiographic appearance of foreign material.5.3 These reference radiographs were produced in accordance with Guide E94. All of the references are original radiographs.5.4 Film Deterioration—Radiographic films are subject to wear and tear from handling and use. The extent to which the image deteriorates over time is a function of storage conditions, care in handling and amount of use. Reference radiograph films are no exception and may exhibit a loss in image quality over time. The radiographs should therefore be periodically examined for signs of wear and tear, including scratches, abrasions, stains, and so forth. Any reference radiographs which show signs of excessive wear and tear which could influence the interpretation and use of the radiographs should be replaced.1.1 These reference radiographs illustrate the categories and severity levels of discontinuities that may occur in aluminum-alloy and magnesium-alloy die castings. They are intended to provide:1.1.1 A guide enabling recognition of discontinuities and their differentiation both as to type and severity level through radiographic examination.1.1.2 Example radiographic illustrations of discontinuities and a nomenclature for reference in acceptance standards, specifications, and drawings.NOTE 1: The set of reference radiographs consists of five 81/2 by 11-in. cardboard frames containing radiographs covering discontinuities in aluminum and magnesium alloy die castings. The first four frames each contain two sets of four graded levels of increasing severity, while the last frame contains two ungraded radiographs. The 5 frames are contained in a 101/2 by 111/2-in. ring binder.NOTE 2: Reference radiographs applicable to aluminum and magnesium castings up to 2 in. (50 mm) in thickness are contained in ASTM Reference Radiographs E155, for Inspection of Aluminum and Magnesium Castings, Volumes I and II.1.2 Two kinds of illustration categories are covered as follows:1.2.1 Graded—Three discontinuity categories for aluminum die castings and three discontinuity categories for magnesium die castings, each illustrated in four levels of progressively increasing severity. Category A discontinuities are illustrated for aluminum and magnesium die castings having thicknesses of 1/8 in. (3.2 mm) and 5/8 in. (15.9 mm); Category B discontinuities are illustrated for 1/8-in. thick aluminum and magnesium die castings; and Category C discontinuities are illustrated for 5/8-in. thick aluminum and magnesium die castings.1.2.2 Ungraded—One illustration of one discontinuity for 0.20-in. (5.1-mm) thickness aluminum die casting; and one illustration of one discontinuity for 1/8-in. (3.2-mm) thickness magnesium die casting.1.3 This document may be used for other materials, thicknesses, or with other energy levels for which it has been found to be applicable and agreement has been reached between the purchaser and manufacturer.1.4 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.1.5 These film reference radiographs are not intended to illustrate the types and degrees of discontinuities found in aluminum and magnesium die castings when performing digital X-ray imaging. When performing digital X-ray imaging of these castings, refer to Digital Reference Images E2973.1.6 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.7 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.1.8 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.