1.1 本规范涵盖用于中速柴油发动机的锻造连续颗粒流（CGF）曲轴的磁粉检测。 1.2 为了进行磁粉探伤评估，曲轴分为四个降低操作应力的区域。已为每个区域设定验收标准。 1.3 安装这些曲轴的发动机通常用于柴油电力机车、船舶推进和发电。以天然气为燃料的发动机也属于这种中速发动机。 1.4 规格 A983/A983M 是涵盖CGF曲轴制造的产品规范。 1.5 以英寸-磅单位或国际单位表示的数值应单独视为标准值。在文本中，国际单位显示在括号中。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。 1.6 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 the magnetic particle examination of forged continuous grain flow (CGF) crankshafts intended for medium speed diesel engines. 1.2 For the purpose of magnetic particle indication assessment, the crankshaft is divided into four zones of decreasing operational stress. Acceptance criteria have been set for each zone. 1.3 The engines to which these crankshafts are fitted are commonly used for diesel electric locomotives, marine propulsion, and power generation. Engines fueled by natural gas also fall into this medium speed category. 1.4 Specification A983/A983M is a product specification that covers the manufacture of CGF crankshafts. 1.5 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 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. 1.6 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.