1.1 本规范涵盖用于特别严重腐蚀应用的铁铬镍合金不锈钢铸件。 1.2 本规范要求对影响拟被腐蚀介质润湿的表面的所有焊补进行焊后热处理。对于不认为必须进行焊后热处理以保持可接受的耐腐蚀性的应用，请参阅规范 A743/A743M . 注1: 对于一般耐蚀合金铸件，应参考规范 A743/A743M . 对于一般耐热合金铸件，应参考规范 A297/A297M . 对于镍基合金铸件，请参阅规范 A494/A494M . 1.3 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。 将两个系统的值合并可能会导致不符合标准。 1.3.1 在文本中，国际单位显示在括号中。 1.3.2 英寸磅单位适用于按规范订购的材料 A744型 按规范订购的材料的国际单位制 A744M . 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。

1.1 This specification covers iron-chromium-nickel alloy stainless steel castings intended for particularly severe corrosive applications. 1.2 This specification requires post-weld heat treatment of all weld repairs affecting surfaces intended to be wetted by the corrosive medium. For applications for which post-weld heat treatment is not considered mandatory for retention of acceptable corrosion resistance, refer to Specification A743/A743M . Note 1: For general corrosion-resistant alloy castings, reference should be made to Specification A743/A743M . For general heat-resistant alloy castings, reference should be made to Specification A297/A297M . For nickel-base alloy castings, refer to Specification A494/A494M . 1.3 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. 1.3.1 Within the text, the SI units are shown in brackets. 1.3.2 Inch-pound units are applicable for material ordered to Specification A744 and SI units for material ordered to Specification A744M . 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.