【国外标准】 Standard Digital Reference Images for Heavy-Walled (2 to 412 in. (50.8 to 114 mm)) Steel Castings

4.1 Graded reference images are intended to provide a guide enabling recognition of specific casting discontinuity types and relative severity levels that may be encountered during typical fabrication processes. Reference images containing ungraded discontinuities are provided as a guide for recognition of a specific casting discontinuity type where severity levels are not needed. These reference images are intended as a basis from which manufacturers and purchasers may, by mutual agreement, select particular discontinuity classes to serve as standards representing minimum levels of acceptability (see Sections 5 and 6).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. Severity levels of similar discontinuity categories and energy level range of Digital Reference Images E2868 reference images may alternatively be used, as determined appropriate for the casting service application, if so agreed upon in a purchaser supplier agreement.4.3 Procedures for evaluation of production images using applicable reference images of this standard are prescribed in Section 7; 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 specifically called-out in the purchaser supplier agreement or contractual document. Section 8 addresses purchaser supplier requisites for where weld repairs may be required.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 These digital reference images illustrate various categories, types, and severity levels of discontinuities occurring in steel castings that have section thicknesses of 2 in. (50.8 mm) to less than 41/2 in. (114 mm). The digital reference images are an adjunct to this standard and must be purchased separately from ASTM International, if needed (see 2.3). 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 acceptance criteria as described in Sections 4, 6, and 7 of this standard.1.2 These digital reference images consist of three separate volumes (see Note 2) as follows: (I) 1 MV X-rays and Iridium-192, (II) 2 MV to 4 MV X-rays and Cobalt-60, and (III) 4 MV to 30 MV X-rays. Unless otherwise specified in a purchaser supplier agreement (see 1.1), each volume is for comparison only with production digital images produced with radiation energy levels within the thickness range covered by this standard. Each volume consists of five categories of graded discontinuities of increasing severity level and three categories of ungraded discontinuities. Reference images containing ungraded discontinuities are provided as a guide for recognition of a specific casting discontinuity type where severity levels are not needed. The following is a list of discontinuity categories, types, and severity levels for the adjunct digital reference images of this standard:1.2.1 Category A—Gas porosity; severity levels 1 through 5.1.2.2 Category B—Sand and slag inclusions; severity levels 1 through 5.1.2.3 Category C—Shrinkage; 3 types:1.2.3.1 Ca – Linear Shrinkage—Severity levels 1 through 5.1.2.3.2 Cb – Feathery Shrinkage—Severity levels 1 through 5.1.2.3.3 Cc – Sponge Shrinkage—Severity levels 1 through 5.1.2.4 Category D—Crack; 1 illustration.1.2.5 Category E—Hot tear; 1 illustration.1.2.6 Category F—Insert; 1 illustration.NOTE 2: The digital reference images consist of the following:Volume I: 1 MV X-rays and Iridium-192Volume II: 2 MV to 4 MV X-rays and Cobalt-60Volume III: 4 MV to 30 MV X-rays1.3 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.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 These digital reference images are not intended to illustrate the types and degrees of discontinuities found in steel castings 2 in. (50.8 mm) to 41/2 in. (114 mm) in thickness when performing film radiography. If performing film radiography of such steel castings, refer to Reference Radiographs E186.1.6 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. (See Note 3.)NOTE 3: Each volume of digital reference images consists of 6 digital data files, software to load the desired format, and specific instructions on the loading process. The 28 reference images in each volume illustrate five categories of graded discontinuities and three categories of ungraded discontinuities. Available from ASTM International Headquarters, Order No: RRE303001-A for Volume I, No: RRE303002-A for Volume II, and No: RRE303003-A for Volume III.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.