1.1 本规范涵盖通过真空电弧熔炼、电子束熔炼或粉末冶金固结制备的非合金和合金钽锭，以生产用于加工各种轧机形状的固结金属。 1.2 本规范涵盖的材料包括: 1.2.1 R05200，非合金钽，电子束炉或真空电弧熔炼，或两者， 1.2.2 R05400，非合金钽，粉末冶金固结， 1.2.3 R05255，钽合金，90 % 钽10 % 钨、电子束炉或真空- 电弧熔化，或两者兼而有之， 1.2.4 R05252，钽合金，97.5 % 钽2.5 % 钨、电子束炉或真空电弧熔炼，或两者，以及， 1.2.5 R05240钽合金，60 % 钽40 % 铌、电子束炉或真空电弧熔炼，或两者兼有。 1.3 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====== 8.1 为了确定是否符合表中所列特性要求的规定限值，应按照实践中的舍入方法对观察值或计算值进行舍入 E29年 .

1.1 This specification covers unalloyed and alloyed tantalum ingots prepared by vacuum-arc melting, electron-beam melting, or powder-metallurgy consolidation to produce consolidated metal for processing to various mill shapes. 1.2 The materials covered by this specification are: 1.2.1 R05200, unalloyed tantalum, electron-beam furnace or vacuum-arc melt, or both, 1.2.2 R05400, unalloyed tantalum, powder-metallurgy consolidation, 1.2.3 R05255, tantalum alloy, 90 % tantalum 10 % tungsten, electron-beam furnace or vacuum-arc melt, or both, 1.2.4 R05252, tantalum alloy, 97.5 % tantalum 2.5 % tungsten, electron-beam furnace or vacuum-arc melt, or both, and, 1.2.5 R05240 tantalum alloy, 60 % tantalum 40 % columbium, electron-beam furnace or vacuum-arc melt, or both. 1.3 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 ====== 8.1 For the purpose of determining compliance with the specified limit for requirements of the properties listed in the tables, an observed value or a calculated value shall be rounded as indicated in accordance with the rounding method of Practice E29 .