1.1 本规范 2. 涵盖一种锰钼和四种锰钼镍合金钢板，用于焊接压力容器结构的淬火和回火条件。 1.2 本规范下的材料有五种类型，分别命名为“A”、“B”、“C”、“D”和“E”。材料也有三种等级，具有以下强度水平。 班 抗拉强度， ksi[MPa] 1. 80至100[550至690] 2. 90至115[620至795] 3. 100至125[690至860] 1.3 1级和2级板的最大厚度仅受成分满足规定机械性能要求的能力的限制； 然而，目前的做法通常将最大厚度限制在12英寸[300 mm]，对于类型A至D，以及对于类型E为7英寸[180 mm]。 1.4 3类板材的最大厚度为2 1. / 2. 英寸[65 mm]适用于A至D型，2 in.[50 mm]适用于E型。 1.5 所有类别板的最小标称厚度为0.25英寸[6.5毫米]。 1.6 这些合金钢板在轧制状态下对运输和搬运过程中的裂纹很敏感，尤其是厚度超过1 英寸[25 毫米]。只有在制造商和买方共同同意的情况下，才能在轧制状态下装运。 1.7 本规范涵盖的板材通常用于核反应堆容器的带线区域，在该区域，材料特性可能受到高辐射水平的影响。 附录X1 提供了一些与此用法相关的信息。 1.8 以英寸磅单位或国际单位制表示的数值应单独视为标准。在正文中，国际单位制显示在括号中。每个系统中规定的数值并不完全相等；因此，每个系统都必须独立使用。将两个系统的值组合在一起可能会导致不符合规范。 1.9 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 2 covers one type of manganese-molybdenum and four types of manganese-molybdenum-nickel alloy steel plates for use in the quenched and tempered condition for the construction of welded pressure vessels. 1.2 Material under this specification is available in five types, designated “A,” “B,” “C,” “D,” and “E.” The material is also available in three classes having the following strength levels. Class Tensile Strength, ksi [MPa] 1 80 to 100 [550 to 690] 2 90 to 115 [620 to 795] 3 100 to 125 [690 to 860] 1.3 The maximum thickness of Class 1 and Class 2 plates is limited only by the capacity of the composition to meet the specified mechanical property requirements; however, current practice normally limits the maximum thickness to 12 in. [300 mm] for Types A through D and to 7 in. [180 mm] for Type E. 1.4 The maximum thickness of Class 3 plates is 2 1 / 2 in. [65 mm] for Types A through D and 2 in. [50 mm] for Type E. 1.5 The minimum nominal thickness of plates of all classes is 0.25 in. [6.5 mm]. 1.6 These alloy steel plates in the as-rolled condition are sensitive to cracking during transit and handling, particularly in thicknesses over 1 in. [25 mm]. They should be shipped in the as-rolled conditions only by mutual agreement of manufacturer and the purchaser. 1.7 Plates covered by this specification are often used in the beltline region of nuclear reactor vessels where the material properties may be affected by high levels of radiation. Appendix X1 provides some information pertinent to this usage. 1.8 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. 1.9 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.