1.1 本标准涵盖了通过与参考射线照片的选定严重程度进行比较，对装配钢焊缝坚固性进行射线照相检查的要求 E390 ，第二卷。基材的变化范围大于0.25至3英寸。（6.4–76 mm），包括厚度。第二卷适用。本标准不适用于船厂使用。 注1: 采用本标准代替Mil-Std.1264-B，标题为“通过与分级ASTM进行比较，对钢焊缝的坚固性进行射线照相检查” E390 参考射线照片”，1989年1月18日。本标准旨在用于与其替代文件相同的应用。当考虑该标准用于新的和/或不同的应用时，用户应仔细审查其要求。 1.2 单位- 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 本标准可用于根据程序和参考射线照片的参考射线照片建立焊缝坚固性的验收标准 E390 . 本标准中规定的等级虽然适用于所示材料和厚度的一般检查，但可能不适用于所有应用。

1.1 This standard covers requirements for radiographic examination for soundness of welds in fabricated steel by comparison to selected severity levels of Reference Radiographs E390 , Vol II. The base material varies from greater than 0.25 to 3 in. (6.4–76 mm) inclusive in thickness. Volume II is applicable. This standard is not suitable for shipyard use. Note 1: This standard was adopted to replace Mil-Std. 1264-B, entitled “Radiographic Inspection For Soundness of Welds In Steel By Comparison To Graded ASTM E390 Reference Radiographs,” dated 18 January, 1989. This standard is intended to be used for the same applications as the document which it replaced. Users should carefully review its requirements when considering the standard's use for new and/or different applications. 1.2 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. 1.3 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. 1.4 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. ====== Significance And Use ====== 4.1 This standard can be used to establish acceptance criteria for weld soundness based on the procedures and reference radiographs of Reference Radiographs E390 . The grades specified in this standard, while applicable for general examination use for the materials and thicknesses indicated, may not be suitable for all applications.