【国外标准】 Standard Digital Reference Images for Tin Bronze Castings

4.1 Reference images for tin bronze and related alloy castings are intended to be used as a guide to the recognition of common discontinuities and their differentiation both as to type and severity level. Discontinuity types most common to these alloys are illustrated. For reference, descriptions of typical casting discontinuities and corresponding image indication types are contained in Section 5. Purchasers and suppliers may, by mutual agreement, select particular discontinuity categories (see 1.2) to serve as standards representing minimum levels of acceptability (see Sections 6 and 7).4.2 Reference images represented by this standard may be used, as agreed upon in a purchaser supplier agreement, for energy levels, thicknesses, or both, outside the range of this standard when determined applicable for the casting service application. Section 9 addresses purchaser supplier requisites where weld repairs may be required.4.3 Procedures for evaluation of production images using applicable reference images of this standard are prescribed in Section 8; however, there may be manufacturing-purchaser issues involving specific casting service applications where it may be appropriate to modify or alter such requirements. Where such modifications may be appropriate for the casting application, all such changes shall be called-out in the purchaser supplier agreement or contractual document.4.4 The following ASTM specifications illustrate alloys covered by these standards; however, it is intended that these reference images also apply to related government and commercial material specifications:Valve bronze castings B61AComposition bronze or ounce metal castings B62BTin bronze sand castings B584Leaded red brass sand castings B584Copper-base alloy centrifugal castings (as applicable) B271(A) Similar to MIL-B-16541.(B) Similar to MIL-B-16444.1.1 These digital reference images illustrate various categories, types and severity levels of discontinuities occurring in tin bronze and related alloy castings. The digital reference images are an adjunct to this document and must be purchased separately from ASTM International if needed (see Section 2). Categories and severity levels for each discontinuity type represented by these digital reference images are described in 1.2.NOTE 1: The basis of application for these reference images requires a prior purchaser supplier agreement of radiographic examination attributes and classification criterion described in Sections 4, 6, and 7 of this standard.1.2 These digital reference images consist of 22 21/2 by 51/2-in. (63.5 by 139.7-mm) nominal size reproductions originally exposed with low voltage X-rays. Fifteen of these images were produced with 1 in. (25.4 mm) plate castings and seven (sand inclusions, inserts, chaplets) were produced with 3/4-in. plate castings originally derived for NAVSHIPS 250-537-1 and -2. The 1-in. plate castings address gas porosity, linear shrinkage, and feathery shrinkage discontinuity types. The original radiographs illustrate discontinuities in sand cast 88:8:4 Cu-Sn-Zn, “G” type, bronze alloy plates and are representative of those found in wide solidification range copper-tin base alloys. The categories, types and severity levels for the adjunct digital reference images of this standard are shown in 1.2.1 to 1.2.5:1.2.1 Category A—Gas porosity; severity levels 1 through 5 for thicknesses up to and including 2 in. (50.8 mm).1.2.2 Category B—Sand inclusions; severity levels 1 through 5 for thicknesses up to and including 2 in. (50.8 mm).1.2.3 Category C—Shrinkage; two types:1.2.3.1 Ca—Linear shrinkage; severity levels 1 through 5 for thicknesses up to and including 2 in. (50.8 mm).1.2.3.2 Cd—Feathery and spongy shrinkage (see Note 2); severity levels 1 through 5 for thicknesses up to and including 2 in. (50.8 mm).NOTE 2: The feathery shrinkage discontinuity type is used to illustrate aggregate severity levels for either feathery or spongy shrinkage discontinuity types (see 5.1).1.2.4 Category D—Hot tear; one illustration.1.2.5 Category E—Inserts, chaplets; one illustration.1.3 All areas of this standard may be subject 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.1.4 These digital reference images are not intended to illustrate the types and degrees of discontinuities found in tin bronze castings when performing film radiography. If performing film radiography of tin bronze castings, refer to Reference Radiographs E310.1.5 Only licensed copies of the software and images shall be utilized for production examination. A copy of the ASTM/User license agreement shall be kept on file for audit purposes (see Note 3).NOTE 3: The digital reference images consist of a set of digital image files, software to load the desired format, and specific instructions on the loading process. The 22 reference images illustrate four categories of graded discontinuities (1.2.1 (Gas porosity), 1.2.2 (Sand inclusion), 1.2.3.1 (Linear shrinkage), and 1.2.3.2 (Feathery shrinkage)) and two categories of ungraded discontinuities (1.2.4 (Hot tear) and 1.2.5 (Inserts)) and contain an image of a step wedge. Available from ASTM International Headquarters, Order No: RRE3185.1.6 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.