1.1 本规程涵盖了利用EMAT技术检测主要暴露在表面的材料不连续性（例如，裂纹、接缝、搭接、冷关、叠层、贯穿泄漏、未熔合）的指南。这种技术也可以对非表面破坏的缺陷和不连续性敏感，前提是它们与表面的接近度小于或等于瑞利波长。 1.2 本规程涵盖了通过电磁场将表面波非接触耦合到材料中的程序。 1.3 本实践的程序适用于可以电磁引入声波的任何材料。 这包括导电或铁磁的任何材料，或两者兼而有之。 1.4 此实践旨在为过程中、最终和维护应用程序提供检查能力。 1.5 本规程未提供衍生适应症的评估标准。指示的解释、分类和最终评估，尽管是必要的，但超出了本实践的范围。需要单独的规范或协议来定义可接受或不可接受的指示的类型、尺寸、位置和方向- 可接受。 1.6 单位-- 以英寸磅为单位的数值应视为标准。括号中给出的值是国际单位制的数学转换，仅供参考，不被视为标准。 1.7 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。 1.8 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====== 5.1 EMAT技术在波模式产生类型的灵活性和不需要流体耦合的特殊应用中显示出优于传统压电超声技术的优点和优势。EMAT在产生表面波方面是高效的。 5.2 由于EMAT在产生表面波方面是高效的，而且利用表面波的声学技术已被证明对检测表面和近表面不连续性是有效的，因此应将其用于传统渗透检测和磁粉无损检测技术有效但不可取的任何应用。 5.3 由于EMAT技术是非接触式的，因此应将其用于超声检测，其中应用涉及自动化、高速检查、移动物体、偏远或危险位置的应用、高温物体或表面粗糙物体的应用。 5.4 本实践的目的是推广超声波方法的EMAT技术，作为检测表面和近表面材料不连续性的传统PT和MPT方法的可行替代方案。 5.5 EMAT的使用和适当操作参数的选择以了解部件的几何形状为前提； 预期缺陷的可能位置、尺寸、方向和反射率；EMAT起飞的允许范围；以及控制超声波传播的物理定律。本程序适用于特定的EMAT表面检查应用程序。

1.1 This practice covers guidelines for utilizing EMAT techniques for detecting material discontinuities that are primarily open to the surface (for example, cracks, seams, laps, cold shuts, laminations, through leaks, lack of fusion). This technique can also be sensitive to flaws and discontinuities that are not surface-breaking, provided their proximity to the surface is less than or equal to the Rayleigh wave length. 1.2 This practice covers procedures for the non-contact coupling of surface waves into a material via electromagnetic fields. 1.3 The procedures of this practice are applicable to any material in which acoustic waves can be introduced electromagnetically. This includes any material that is either electrically conductive or ferromagnetic, or both. 1.4 This practice is intended to provide examination capabilities for in-process, final, and maintenance applications. 1.5 This practice does not provide standards for the evaluation of derived indications. Interpretation, classification, and ultimate evaluation of indications, albeit necessary, are beyond the scope of this practice. Separate specifications or agreement will be necessary to define the type, size, location, and direction of indications considered acceptable or non-acceptable. 1.6 Units— The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.7 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. 1.8 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 ====== 5.1 EMAT techniques show benefits and advantages over conventional piezoelectric ultrasonic techniques in special applications where flexibility in the type of wave mode generation and where no fluid coupling is desired. EMATs are highly efficient in the generation of surface waves. 5.2 Since EMATs are highly efficient in the generation of surface waves, and since acoustic techniques utilizing surface waves are proven effective for detecting surface and near-surface discontinuities, they should be considered for any applications where conventional penetrant testing and magnetic particle NDT techniques are effective but undesirable. 5.3 Since EMAT techniques are non-contacting, they should be considered for ultrasonic testing where applications involve automation, high-speed examinations, moving objects, applications in remote or hazardous locations, applications to objects at elevated temperatures, or objects with rough surfaces. 5.4 The purpose of this practice is to promote the EMAT technique of the ultrasonic method as a viable alternative to conventional PT and MPT methods for detecting the presence of surface and near-surface material discontinuities. 5.5 The use of EMATs and the selection of appropriate operating parameters presuppose a knowledge of the geometry of the component; the probable location, size, orientation, and reflectivity of the expected flaws; the allowable range of EMAT lift-off; and the laws of physics governing the propagation of ultrasonic waves. This procedure pertains to a specific EMAT surface inspection application.