1.1 本规范 2. 用于压力容器的相对薄壁锻件（包括气瓶）。包括三种碳钢和六种合金钢。规定了无缝管或管子制成的容器体端部的整体锻造。 注1: 当按照本规范的化学和拉伸要求工作时，壁厚和冷却速度的影响必然会消除每类锻件的某些尺寸。 注2: 名称变更如下: 现在的 从前 A级 I型 B级 II型 C级 III型 D级 IV型 E级55级 V型1级55级 E级65级 V型1级65级 E级70级 V型1级70级 F级55级 V型2级55级 F级65级 V型2级65级 F级70级 V型2级70级 G级55级 V型3级55级 G级65级 V型3级65级 G级70级 V型3级70级 H级55级 V型4年级55班 H级65级 V型4级65级 H级70级 V型4级70级 J级55级 V型5级55班 J级65级 V型5级65级 J级70级 V型5级70级 K级 VI型 L级 VII型 J级110级 VIII型 M级85级 IX型A类 M级100级 第九类B类 1.2 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不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。 1.3 除非订单规定了适用的“M”规格名称（国际单位制），否则材料应以英寸为单位提供- 磅单位。 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 2 covers relatively thin-walled forgings (including gas bottles) for pressure vessel use. Three types of carbon steel and six types of alloy steel are included. Provision is made for integrally forging the ends of vessel bodies made from seamless pipe or tubing. Note 1: When working to the chemical and tensile requirements of this specification, the influence of wall thickness and cooling rate will necessarily eliminate certain forging sizes in each class. Note 2: Designations have been changed as follows: Current Formerly Grade A Type I Grade B Type II Grade C Type III Grade D Type IV Grade E Class 55 Type V Grade 1 Class 55 Grade E Class 65 Type V Grade 1 Class 65 Grade E Class 70 Type V Grade 1 Class 70 Grade F Class 55 Type V Grade 2 Class 55 Grade F Class 65 Type V Grade 2 Class 65 Grade F Class 70 Type V Grade 2 Class 70 Grade G Class 55 Type V Grade 3 Class 55 Grade G Class 65 Type V Grade 3 Class 65 Grade G Class 70 Type V Grade 3 Class 70 Grade H Class 55 Type V Grade 4 Class 55 Grade H Class 65 Type V Grade 4 Class 65 Grade H Class 70 Type V Grade 4 Class 70 Grade J Class 55 Type V Grade 5 Class 55 Grade J Class 65 Type V Grade 5 Class 65 Grade J Class 70 Type V Grade 5 Class 70 Grade K Type VI Grade L Type VII Grade J Class 110 Type VIII Grade M Class 85 Type IX Class A Grade M Class 100 Type IX Class B 1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.3 Unless the order specifies the applicable “M” specification designation (SI units), the material shall be furnished to inch-pound units. 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.