1.1 本规范涵盖能够通过沉淀硬化热处理进行强化的铁铬镍铜耐腐蚀钢铸件。 1.2 这些铸件可用于要求在高达600的温度下具有耐腐蚀性和高强度的服务 °F[315 °C]。它们可以在固溶热处理条件下进行机加工，随后沉淀硬化至 表S51.1 几乎没有破裂或变形的危险。 1.3 该材料不适用于固溶热处理条件。 注1: 如果使用材料的使用环境被认为有利于应力- 腐蚀开裂、沉淀硬化应在将材料对此类侵蚀的敏感性降至最低的温度下进行。 1.4 提供了可选性质的补充要求，供买方选择使用。只有当买方在采购订单或合同中单独规定时，补充要求才适用。 1.5 本规范以英寸磅单位和国际单位制表示；但是，除非采购订单或合同规定了适用的M规格名称（SI单位），否则应采用英寸磅单位。 1.6 以国际单位制或英寸表示的数值- 磅单位应单独视为标准单位。每个系统中规定的值可能不是完全相等的；因此，每个系统应独立使用。将两个系统的值结合起来可能会导致不符合标准。在正文中，国际单位制显示在括号中。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。

1.1 This specification covers iron-chromium-nickel-copper corrosion-resistant steel castings, capable of being strengthened by precipitation hardening heat treatment. 1.2 These castings may be used in services requiring corrosion resistance and high strengths at temperatures up to 600 °F [315 °C]. They may be machined in the solution heat-treated condition and subsequently precipitation hardened to the desired high-strength mechanical properties specified in Table S51.1 with little danger of cracking or distortion. 1.3 The material is not intended for use in the solution heat-treated condition. Note 1: If the service environment in which the material is to be used is considered conducive to stress-corrosion cracking, precipitation hardening should be performed at a temperature that will minimize the susceptibility of the material to this type of attack. 1.4 Supplementary requirements of an optional nature are provided for use at the option of the purchaser. The supplementary requirements shall apply only when specified individually by the purchaser in the purchase order or contract. 1.5 This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order or contract specifies the applicable M-specification designation (SI units), the inch-pound units shall apply. 1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. Within the text, the SI units are shown in brackets. 1.7 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.