1.1 本规程提供了无压造纸机辊的声发射（AE）检查指南。 1.2 这种做法利用轧辊的缓慢旋转产生全负荷循环，其中负荷由悬挂在其轴承或其他轴颈支撑机构上的轧辊重量提供。 1.3 本规程用于检测在旋转过程中产生摩擦声发射的轧辊中的裂纹和其他不连续性。 1.4 声发射测量用于检测或定位发射源，或两者兼而有之。必须使用其他无损检测（NDT）方法来评估声发射源的重要性。其他无损检测技术的程序不在本规程范围内。 看见 注1 . 注1: 传统的声发射检测、磁粉检测、剪切波超声波检测和射线照相通常用于确定产生声发射的缺陷的准确位置和尺寸。 1.5 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。 1.6 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。 第节给出了具体的预防说明 8. . 1.7 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====== 5.1 纸机辊的尺寸范围为2.4到9米[8到30英尺]长，外壳厚度为12.5到75毫米[0.5到3英寸，]和300到1200毫米[12到48英寸。]直径根据用途，纸机辊的重量可低至6000kg[13000lb]至27000kg[6000lb]。 5.2 如果在此过程中发现指示，可以重复该过程，并使用额外的传感器来提高源位置精度。 5.3 为进行传统无损检测而移除轧辊可能不切实际，并且可能不够敏感，无法定位小缺陷。 5.4 传统的声发射检测，即轧辊承受大于工作载荷的载荷以检测裂纹扩展，有损坏轧辊的风险，最好用作后续无损检测。 5.5 通过全回转进行手动旋转，使现有裂纹承受拉伸和压缩力，从而打开和闭合现有裂纹，并在裂纹表面产生摩擦。 5.6 过量的背景噪声（桥式起重机、附近的维护活动）可能会扭曲声发射数据或使其无效。 用户必须了解以下常见背景噪声源:轴承噪声（缺乏润滑、剥落等）、其他物体与轧辊的机械接触、来自附近广播设施和其他来源的电磁干扰（EMI）和射频干扰（RFI）。如果无法消除或控制背景噪声，则不应使用此做法。 5.7 其他无损检测方法可用于评估声发射指示的重要性。传统的声发射已用于确认声发射指示的存在并微调位置。磁粉、超声波和射线照相检查已用于确定显示的位置、深度和尺寸。 使用其他无损检测方法的程序不在本规程范围内。

1.1 This practice provides guidelines for acoustic emission (AE) examinations of non-pressure, paper machine rolls. 1.2 This practice utilizes a slow rotation of the roll to produce a full load cycle where load is provided by the weight of the roll suspended from its bearings or other journal support mechanism(s). 1.3 This practice is used for detection of cracks and other discontinuities in rolls that produce frictional acoustic emission during rotation. 1.4 The AE measurements are used to detect or locate emission sources, or both. Other nondestructive test (NDT) methods must be used to evaluate the significance of AE sources. Procedures for other NDT techniques are beyond the scope of this practice. See Note 1 . Note 1: Traditional AE examination, magnetic particle examination, shear wave ultrasonic examination, and radiography are commonly used to establish the exact position and dimensions of flaws that produce AE. 1.5 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. 1.6 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. Specific precautionary statements are given in Section 8 . 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 ====== 5.1 Paper machine rolls can range in size from 2.4 to 9 m [8 to 30 ft] long, with a shell thickness of from 12.5 to 75 mm [0.5 to 3 in.,] and 300 to 1200 mm [12 to 48 in.] diameter. Depending on purpose, paper machine rolls can weigh as little as 60 000 kg [13 000 lb] to as much as 27 500 kg [60 000 lb]. 5.2 If indications are found during this procedure it can be repeated, with additional sensors to refine source location accuracy. 5.3 Removal of rolls for traditional NDT examination may be impractical and may not be sensitive enough to locate small defects. 5.4 Traditional AE examination, whereby the roll is subjected to load greater than service load to detect crack extension, risks damage to the roll and is best employed as a follow-up NDT examination. 5.5 Manual rotation through a full revolution subjects existing cracks to tensile and compressive forces which can open and close existing cracks, and cause friction at the crack surfaces. 5.6 Excess background noise (overhead cranes, nearby maintenance activities) may distort AE data or render it useless. Users must be aware of the following common sources of background noise: bearing noise (lack of lubrication, spalling, and so forth), mechanical contact with the roll by other objects, electromagnetic interference (EMI) and radio frequency interference (RFI) from nearby broadcasting facilities and from other sources. This practice should not be used if background noise cannot be eliminated or controlled. 5.7 Other Non-destructive test methods may be used to evaluate the significance of AE indications. Traditional AE has been used to confirm the existence of the AE indication and fine tune the location. Magnetic particle, ultrasonic and radiographic examinations have been used to establish the position, depth and dimensions of the indication. Procedures for using other NDT methods are beyond the scope of this practice.