1.1 本规程提供了在连续焊接工艺制造期间和之后立即对焊接件进行声发射（AE）监测的建议。 1.2 本规程中描述的程序适用于焊接件及其制造过程中热影响区内声发射源的检测和定位，特别是在焊接持续时间足以在焊接过程中发生熔合和凝固的情况下。 1.3 声发射检测焊接件和热影响区中不连续性的有效性取决于声发射系统的设计、声发射系统验证程序、焊接工艺和材料类型。 被监测的材料包括低碳钢、低合金钢、不锈钢和一些铝合金。必须通过证明可以以所需的可靠性检测到相关缺陷来验证每个应用的系统性能。 1.4 单位- 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。 本标准的用户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。 1.6 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。 ====意义和用途====== 4.1 制造过程中焊接件中声发射源的检测和定位可提供与焊缝完整性相关的信息。 此类信息可用于指导焊缝的修复程序，或作为其他无损评价（NDE）方法应用的指南。将声发射应用于焊缝过程中监测的一个主要属性是该方法能够立即提供关于焊缝完整性的实时信息。这一特点使该方法有助于通过在生产过程中最方便的点修复缺陷来降低焊接成本。焊接过程中的热应力刺激了焊接件中不连续处的声发射活动。由该刺激产生的声发射活动由焊件附近的声发射传感器检测，该传感器将声波转换为电子信号。 AE仪器处理信号，并提供即时显示或指示AE活动以及永久记录数据的方法。 4.2 准备和规划监测时应考虑的事项应包括但不限于以下内容: 4.2.1 待监测或检查的系统或对象的描述， 4.2.2 监测范围，即整个焊缝、仅覆盖焊道等， 4.2.3 传感器安装程序的限制或限制（如适用）， 4.2.4 在声发射系统验证过程中建立和维护的性能参数（灵敏度、定位精度等）， 4.2.5 AE系统验证检查之间的最大时间间隔， 4.2.6 采购设备的性能标准， 4.2.7 AE响应的永久记录要求（如适用）， 4.2.8 测试报告的内容和格式（如需要），以及 4.2.9 操作员资格和认证（如需要）。

1.1 This practice provides recommendations for acoustic emission (AE) monitoring of weldments during and immediately following their fabrication by continuous welding processes. 1.2 The procedure described in this practice is applicable to the detection and location of AE sources in weldments and in their heat-affected zone during fabrication, particularly in those cases where the time duration of welding is such that fusion and solidification take place while welding is still in progress. 1.3 The effectiveness of acoustic emission to detect discontinuities in the weldment and the heat-affected zone is dependent on the design of the AE system, the AE system verification procedure, the weld process, and the material type. Materials that have been monitored include low-carbon steels, low-alloy steels, stainless steels, and some aluminum alloys. The system performance must be verified for each application by demonstrating that the defects of concern can be detected with the desired reliability. 1.4 Units— 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 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. 1.6 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. ====== Significance And Use ====== 4.1 Detection and location of AE sources in weldments during fabrication may provide information related to the integrity of the weld. Such information may be used to direct repair procedures on the weld or as a guide for application of other nondestructive evaluation (NDE) methods. A major attribute of applying AE for in-process monitoring of welds is the ability of the method to provide immediate real-time information on weld integrity. This feature makes the method useful to lower weld costs by repairing defects at the most convenient point in the production process. The AE activity from discontinuities in the weldment is stimulated by the thermal stresses from the welding process. The AE activity resulting from this stimulation is detected by AE sensors in the vicinity of the weldment, which convert the acoustic waves into electronic signals. The AE instrumentation processes signals and provides means for immediate display or indication of AE activity and for permanent recordings of the data. 4.2 Items to be considered in preparation and planning for monitoring should include but not be limited to the following: 4.2.1 Description of the system or object to be monitored or examined, 4.2.2 Extent of monitoring, that is, entire weld, cover passes only, and so forth, 4.2.3 Limitations or restrictions on the sensor mounting procedures, if applicable, 4.2.4 Performance parameters to be established and maintained during the AE system verification procedure (sensitivity, location accuracy, and so forth), 4.2.5 Maximum time interval between AE system verification checks, 4.2.6 Performance criteria for purchased equipment, 4.2.7 Requirements for permanent records of the AE response, if applicable, 4.2.8 Content and format of test report, if required, and 4.2.9 Operator qualification and certification, if required.