1.1 这种做法 2. 介绍了用直线和角束技术对钢锻件进行接触、脉冲回波超声波检测的检测程序。直波束技术包括利用DGS（距离增益大小）方法。看见 附录X3 。 1.2 只要询价、合同、订单或规范规定锻件应按照惯例进行超声波检查，则应使用本惯例 3888/3888米 。 1.3 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。 1.4 以国际单位制或英寸磅单位表示的数值应单独视为标准。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。组合两个系统的值可能导致- 符合标准。 1.5 本规程和适用材料规范均以英寸磅单位和国际单位制表示。但是，除非订单规定了适用的“M”规格名称[SI单位]，否则材料应以英寸磅单位提供。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 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。 ===意义和用途====== 4.1 当订单或规范要求进行超声波检查时，应使用本规程进行检查，其中锻件的验收是基于不连续的数量、振幅或位置的限制，或其组合，这会产生超声波指示。 4.2 超声波质量等级应明确规定为订单要求。

1.1 This practice 2 covers the examination procedures for the contact, pulse-echo ultrasonic examination of steel forgings by the straight and angle-beam techniques. The straight beam techniques include utilization of the DGS (Distance Gain-Size) method. See Appendix X3 . 1.2 This practice is to be used whenever the inquiry, contract, order, or specification states that forgings are to be subject to ultrasonic examination in accordance with Practice A388/A388M . 1.3 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. 1.4 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 non-conformance with the standard. 1.5 This practice and the applicable material specifications are expressed in both inch-pound units and SI units. However, unless the order specifies the applicable “M” specification designation [SI units], the material shall be furnished to inch-pound units. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 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. ====== Significance And Use ====== 4.1 This practice shall be used when ultrasonic inspection is required by the order or specification for inspection purposes where the acceptance of the forging is based on limitations of the number, amplitude, or location of discontinuities, or a combination thereof, which give rise to ultrasonic indications. 4.2 The ultrasonic quality level shall be clearly stated as order requirements.