【国外标准】 Standard Reference Radiographs for High-Strength Copper-Base and Nickel-Copper Alloy Castings

4.1 Personnel Qualification—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. Personnel shall be authorized to perform radiographic interpretation by the employer. 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).4.2 Reference radiographs for high-strength copper-base and nickel-copper 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. Other discontinuity types such as hot tears, cracks, and unfused chaplets are illustrated in applicable Reference Radiographs E186, E192, and E446. For reference, descriptions of typical casting defects and corresponding radiographic indication types are contained in Section 5. Purchasers and suppliers may, by mutual agreement, select particular discontinuity classes (see 1.2) to serve as standards representing minimum levels of acceptability. (See Sections 7 and 8.)4.3 Reference radiographs 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.4.4 Procedures for evaluation of production radiographs using applicable reference radiographs of this standard are prescribed in Section 9; 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. Section 10 addresses purchaser supplier requisites where weld repairs may be required.4.5 The following ASTM specifications illustrate alloys that may be used with these standards. It is intended that these reference radiographs also apply to related government and commercial material specifications.Alloys ASTM SpecificationsA    Aluminum Bronze B148   Nickel-Aluminum Bronze B148   Copper-Nickel B369   Manganese Bronze B584Alloys Government SpecificationA Manganese-Nickel-Aluminum Bronze MIL-B-21230A—Alloy No. 2.Nickel-Copper MIL-B-21230A—Alloy No. 2.(A) See Section 2 for the complete title(s) of these specification(s).1.1 These reference radiographs illustrate various categories, types, and severity levels of discontinuities occurring in high-strength copper-base, nickel-copper, and related alloy castings. The reference radiograph films are an adjunct to this document and must be purchased separately from ASTM International, if needed (see 2.3). Categories and severity levels for each discontinuity type represented by these reference radiographs are described in 1.2.NOTE 1: The basis of application for these reference radiographs requires a prior purchaser supplier agreement of radiographic examination attributes and classification criterion described in Sections 4, 7, 8, 9, and 10 of this standard.1.2 These reference radiographs consist of forty-five 5 by 7 in. (127 by 178 mm) nominal size reproductions (20 made from 1 in. (25.4 mm) plate castings exposed with low voltage X-rays for thicknesses up to and including 2 in.) and 25 made from 3 in. (76 mm) plate castings exposed with 2 MV X-rays or Cobalt 60 isotope for thicknesses greater than 2 in. up to and including 6 in. Unless otherwise specified in a purchaser supplier agreement (see 1.1), each discontinuity category is for comparison only with production radiographs produced with radiation energy levels within the thickness range covered by the category. These reference radiographs illustrate discontinuities in sand-cast manganese-nickel-aluminum bronze-alloy plates and are representative of those found in narrow freezing range (formerly “high shrinkage”), high-strength copper and nickel-copper alloys. Following is a list of discontinuity categories, types, and severity levels for the adjunct reference radiographs of this standard (see Note 2):1.2.1 Category A—Gas porosity; severity levels 1 through 5 for two thickness ranges.1.2.1.1 AX—Up to and including 2 in. (50.8 mm) (called “Code A Discontinuity type” in previous revisions).1.2.1.2 AG—Greater than 2 in. (50.8 mm) up to and including 6 in. (152.4 mm) (called “Code A Discontinuity type” in previous revisions).1.2.2 Category B—Inclusions.1.2.2.1 Ba—Sand inclusions, severity levels 1 through 5 for two thickness ranges.(1) BaX—Up to and including 2 in. (50.8 mm) (called “Code Ba Discontinuity type” in previous revisions).(2) BaG—Greater than 2 in. (50.8 mm) up to and including 6 in. (152.4 mm) (called “Code Ba Discontinuity type” in previous revisions).1.2.2.2 Bb—Dross inclusions, severity levels 1 through 5 for two thickness ranges.(1) BbX—Up to and including 2 in. (50.8 mm) (called “Code Bb Discontinuity type” in previous revisions).(2) BbG—greater than 2 in. (50.8 mm) up to and including 6 in. (152.4 mm) (called “Code Bb Discontinuity type” in previous revisions).1.2.3 Category C—Shrinkage; three types1.2.3.1 Ca—linear shrinkage, severity levels 1 through 5 for thicknesses 2 in. up to and including 6 in. (50.8 to 152.4 mm).1.2.3.2 Cb—feathery shrinkage, severity levels 1 through 5 for thicknesses up to and including 2 in. (50.8 mm). (Called “Cd feathery shrinkage” in previous revisions.)1.2.3.3 Cc—spongy shrinkage, severity levels 1 through 5 for thicknesses 2 in. up to and including 6 in. (50.8 to 152.4 mm) (called “Cd spongy shrinkage” in previous revisions).NOTE 2: Discontinuity classes designated with a subscript “X” were produced with low energy X-ray radiation; discontinuity classes designated with subscript “G” were produced with Cobalt 60 or 2 MV X-rays, or both, and are the same reference radiographs and thickness ranges used in previous editions of this standard. Section 4 details the significance and use of these reference radiographs.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 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.1.5 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.