【国外标准】 Standard Digital Reference Images for Investment Steel Castings for Aerospace Applications

4.1 Personnel utilizing reference radiographs to this standard shall be qualified to perform radiographic interpretation in accordance with a nationally or internationally recognized NDT personnel qualification practice or standard 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. If assistance is needed with interpreting specifications and product requirements as applied to the reference radiographs, a certified Level III shall be consulted before accept/reject decisions are made (if the Level III is the radiographic interpreter, this may be the same person).4.2 These digital reference images are intended for reference only, but are designed such that acceptance standards, which may be developed for particular requirements, can be specified in terms of these digital reference images. The illustrations are digital images of castings that were produced under conditions designed to develop the discontinuities.4.2.1 Graded Discontinuities: 4.2.1.1 Gas holes, sponge shrinkage, dendritic shrinkage, less dense foreign material(1) The images of the 1/8-in (3.2-mm) castings are intended to be used in the thickness range up to and including 1/4-in (6.3-mm). The images of the 3/8-in (9.5-mm) castings are intended to be used in the thickness range of over 1/4-in (6.4-mm), up to and including 1/2-in (12.7-mm). The images of the 3/4-in (19.1-mm) castings are intended to be used in the thickness range of over 1/2-in (12.7-mm), up to and including 1-in. (25.4-mm).4.2.1.2 Cavity Shrinkage, Filamentary Shrinkage: (1) The images of the 3/4-in (19.1-mm) castings are intended to be used in the thickness range up to and including 1-in. (25.4-mm).4.2.2 Ungraded Discontinuities: 4.2.2.1 The images of the 3/8-in (9.5-mm) castings are intended to be used in the thickness range up to and including 1-in. (25.4-mm).4.3 Image Deterioration—Many conditions can affect the appearance and functionality of digital reference images. For example, electrical interference, hardware incompatibilities, and corrupted files and drivers may affect their appearance. The Practice E2002 line pair gauges located in each digital reference image can be used as an aid to detect image deterioration by comparing the measured resolution using the gauges to the resolution stated on the digital reference image. Do not use the digital reference images if their appearance has been adversely affected such that the interpretation and use of the images could be influenced.4.4 Agreement should be reached between cognizant engineering organization and the supplier that the system used by the supplier is capable of detecting and classifying the required discontinuities.1.1 The digital reference images provided in the adjunct to this standard illustrate various types and degrees of discontinuities occurring in thin-wall steel investment castings.2 Use of this standard for the specification or grading of castings requires procurement of the adjunct digital reference images which illustrate the discontinuity types and severity levels. They are intended to provide the following:1.1.1 A guide enabling recognition of thin-wall steel casting discontinuities and their differentiation both as to type and degree through digital radiographic examination.1.1.2 Example digital radiographic illustrations of discontinuities and a nomenclature for reference in acceptance standards, specifications, and drawings.1.2 Two illustration categories are covered as follows:1.2.1 Graded—Six common discontinuity types each illustrated in eight degrees of progressively increasing severity.1.2.2 Ungraded—Twelve single illustrations of additional discontinuity types and of patterns and imperfections not generally regarded as discontinuities.1.3 The reference radiographs were developed for casting sections up to 1 in. (25.4 mm) in thickness.1.4 All areas of this standard may be open to agreement between the cognizant engineering organization and the supplier, or specific direction from the cognizant engineering organization. These items should be addressed in the purchase order or the contract.NOTE 1: The set of digital reference images consists of 16 digital files, software to load the desired format, and specific instructions on the loading process. The 16 reference images illustrate eight grades of severity in six common discontinuity types and twelve ungraded discontinuities and contain an image of a step wedge and two duplex-wire gauges. Available from ASTM International Headquarters. Order number RRE2660. Refer to Practice E2002 for wire pair details.1.5 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.1.6 These digital reference images are not intended to illustrate the types or degrees of discontinuities when performing film radiography. If performing film radiography of thin-wall investment castings, refer to Reference Radiographs E192.1.7 Only licensed copies of the software and images shall be utilized for production inspection. A copy of the ASTM/User license agreement shall be kept on file for audit purposes.1.8 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.1.9 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.