1.1 本超声波检验实施规程涵盖规范所涵盖的涡轮机和发电机钢转子锻件 A469/A469米 , A470/A470M , A768/A768米 和 A940/A940米 。本规程仅用于接触测试。 1.2 本规程描述了超声波检查涡轮机和发电机转子锻件的基本程序。当适用的采购文件要求时，它并不限制使用其他超声波方法，如参考块校准，也不打算限制使用新的和改进的超声波测试设备和方法。 1.3 本规程旨在提供一种检查圆柱形锻件的方法，使锻件中心线或孔表面的检查灵敏度恒定，与锻件或孔直径无关。 为此，通过理论分析和实验验证，计算了检测灵敏度的倍增因子。这些绘制在 图1 （钻孔转子）和 图2 （实心转子），用于2.25 MHz的真实检查频率和2.30的声速 英寸/s×10 5. 英寸/秒[5.85 cm/s×10 5. cm/s]。提供了转换为其他灵敏度级别的方法 图3 。（其他频率的灵敏度倍增因子可根据 X1.1 和 X1.2 属于 附录X1 .) 图1 钻孔锻件 注1: 灵敏度倍增因子使得10 % 锻件孔表面的指示相当于 1. / 8. in.[3mm]直径的平底孔。检查频率:2.0 MHz或2.25 MHz。材料速度: 2.30英寸/s×10 5. 英寸/秒[5.85厘米/秒×10 5. cm/s]。 图2 实心锻件 注1: 灵敏度倍增系数，使锻件中心线表面的10%指示等于 1. / 8. in.[3mm]直径的平底孔。检查频率:2.0 MHz或2.25 MHz。物料速度:2.30 in./s×10 5. 英寸/秒[5.85厘米/秒×10 5. cm/s]。 图3 与结合使用的转换因子 图1 和 图2 如果需要改变参考反射器直径 1.4 已经为该方法生成了大量的验证数据，这些数据表明，即使在受控条件下，根据最小等效尺寸平底孔估计自然不连续性也可能存在非常显著的不确定性。存在的可能性是，根据比较平面的最小面积，估计的自然不连续的最小面积- 就自然不连续性的实际面积而言，井底可能相差20dB（因子10）。这种不准确程度并不适用于所有结果，但应视为一种可能性。如果使用调谐仪器，则对所使用的实际频率、线圈带通宽度等的严格控制往往会减少容易出现的总体不准确度。 1.5 本检验规程适用于外径不小于2.5英寸[64的实心圆柱形锻件 毫米]或不大于100英寸[2540毫米]。它也适用于壁厚为2.5[64 mm]in.或更大的同心圆柱形孔的圆柱形锻件，其外径限制与实心圆柱体相同。直径小于15英寸[380 mm]的实心截面和直径小于7。 5英寸[190毫米]壁厚——用于检查的换能器与用于较大截面的换能器不同。 1.6 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。 1.7 这种做法以英寸磅单位和国际单位制表示；但是，除非采购订单或合同规定了适用的M规格名称（SI单位），否则应采用英寸磅单位。以英寸磅单位或国际单位制表示的数值应单独视为标准。在实践中，国际单位制单位显示在括号中。每个系统中规定的值不一定是完全相等的； 因此，为了确保符合标准，每个系统应独立使用，并且不得将两个系统的值组合使用。 1.8 本标准并不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。 1.9 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。 ====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 验收标准应明确规定为订单要求。

1.1 This practice for ultrasonic examination covers turbine and generator steel rotor forgings covered by Specifications A469/A469M , A470/A470M , A768/A768M , and A940/A940M . This practice shall be used for contact testing only. 1.2 This practice describes a basic procedure of ultrasonically inspecting turbine and generator rotor forgings. It does not restrict the use of other ultrasonic methods such as reference block calibrations when required by the applicable procurement documents nor is it intended to restrict the use of new and improved ultrasonic test equipment and methods as they are developed. 1.3 This practice is intended to provide a means of inspecting cylindrical forgings so that the inspection sensitivity at the forging center line or bore surface is constant, independent of the forging or bore diameter. To this end, inspection sensitivity multiplication factors have been computed from theoretical analysis, with experimental verification. These are plotted in Fig. 1 (bored rotors) and Fig. 2 (solid rotors), for a true inspection frequency of 2.25 MHz, and an acoustic velocity of 2.30 in./s × 10 5 in./s [5.85 cm/s × 10 5 cm/s]. Means of converting to other sensitivity levels are provided in Fig. 3 . (Sensitivity multiplication factors for other frequencies may be derived in accordance with X1.1 and X1.2 of Appendix X1 .) FIG. 1 Bored Forgings Note 1: Sensitivity multiplication factor such that a 10 % indication at the forging bore surface will be equivalent to a 1 / 8 in. [3 mm] diameter flat bottom hole. Inspection frequency: 2.0 MHz or 2.25 MHz. Material velocity: 2.30 in./s × 10 5 in./s [5.85 cm/s × 10 5 cm/s]. FIG. 2 Solid Forgings Note 1: Sensitivity multiplication factor such that a 10 % indication at the forging centerline surface will be equivalent to a 1 / 8 in. [3 mm] diameter flat bottom hole. Inspection frequency: 2.0 MHz or 2.25 MHz. Material velocity: 2.30 in./s × 10 5 in./s [5.85 cm/s × 10 5 cm/s]. FIG. 3 Conversion Factors to Be Used in Conjunction with Fig. 1 and Fig. 2 if a Change in the Reference Reflector Diameter is Required 1.4 Considerable verification data for this method have been generated which indicate that even under controlled conditions very significant uncertainties may exist in estimating natural discontinuities in terms of minimum equivalent size flat-bottom holes. The possibility exists that the estimated minimum areas of natural discontinuities in terms of minimum areas of the comparison flat-bottom holes may differ by 20 dB (factor of 10) in terms of actual areas of natural discontinuities. This magnitude of inaccuracy does not apply to all results but should be recognized as a possibility. Rigid control of the actual frequency used, the coil bandpass width if tuned instruments are used, and so forth, tend to reduce the overall inaccuracy which is apt to develop. 1.5 This practice for inspection applies to solid cylindrical forgings having outer diameters of not less than 2.5 in. [64 mm] nor greater than 100 in. [2540 mm]. It also applies to cylindrical forgings with concentric cylindrical bores having wall thicknesses of 2.5 [64 mm] in. or greater, within the same outer diameter limits as for solid cylinders. For solid sections less than 15 in. [380 mm] in diameter and for bored cylinders of less than 7.5 in. [190 mm] wall thickness the transducer used for the inspection will be different than the transducer used for larger sections. 1.6 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. 1.7 This practice is expressed in both inch-pound units and in SI units; however, unless the purchase order or contract specifies the applicable M specification designation (SI units), the inch-pound units shall apply. The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the practice, 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. 1.8 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. 1.9 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. ====== 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 acceptance criteria shall be clearly stated as order requirements.