1.1 本试验方法包括对厚度等于或大于0.500英寸的铝合金板进行脉冲回波超声波检查。（12.7 mm），用于制造压力容器。超声波检测用于检测平行于轧制表面的方向上的总内部不连续性，如裂纹、破裂和层压，并确保只有不存在可拒收不连续性的板材才能交付。 1.2 本标准中包括的检验方法和验收标准应限于以下铝合金板材:1060、1100、3003、包铝3003、3004、包铝3004、5050、5052、5083、5086、5154、5254、5454、5456、5652、6061和包铝6061。 1.3 本试验方法仅适用于使用脉冲纵波的超声波试验，脉冲纵波由包含单晶或电互连多晶体组合的搜索单元发射和接收。 不包括采用穿透透射或角束技术的超声波检测。 1.4 当合同、采购订单或参考板材规范要求进行本文规定的超声波检查时，应使用本试验方法。 1.5 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 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和健康实践，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（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 许多因素，例如板材入口和背面的条件，超声波束相对于入口表面的倾角，测试系统的性能特征可能会导致孤立显示的减少或背反射的大量损失，从而可能严重损害本标准中概述的测试程序的可靠性。 4.2 不连续尺寸的准确评估也可能受到大多数搜索单元中存在的光束特性变化的显著限制。因此，通过本方法中概述的试验程序确定的不连续尺寸被视为“明显的”或“估计的”，以识别测量的有限定量值。 4.3 由于测试系统中的大量交互变量可能会对超声波测试结果产生不利影响，因此难以确定检测到的不连续性对受检板机械性能的实际定量影响。 因此，这种超声波检测方法不适用于作为压力容器最终质量和性能的唯一指标，但可提供可靠的板材质量控制，以避免容器制造成型过程中出现故障。

1.1 This test method covers pulse-echo ultrasonic inspection of aluminum-alloy plate of thickness equal to or greater than 0.500 in. (12.7 mm) for use in the fabrication of pressure vessels. The ultrasonic test is employed to detect gross internal discontinuities oriented in a direction parallel to the rolled surface such as cracks, ruptures, and laminations, and to provide assurance that only plate that is free from rejectable discontinuities is accepted for delivery. 1.2 The inspection method and acceptance criteria included in this standard shall be limited to plate of the following aluminum alloys: 1060, 1100, 3003, Alclad 3003, 3004, Alclad 3004, 5050, 5052, 5083, 5086, 5154, 5254, 5454, 5456, 5652, 6061, and Alclad 6061. 1.3 This test method applies only to ultrasonic tests using pulsed longitudinal waves which are transmitted and received by a search unit containing either a single crystal or a combination of electrically interconnected multiple crystals. Ultrasonic tests employing either the through-transmission or the angle-beam techniques are not included. 1.4 This test method shall be used when ultrasonic inspection as prescribed herein is required by the contract, purchase order, or referenced plate specification. 1.5 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. 1.6 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 and health 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 A number of factors such as the condition of the entry and back surfaces of the plate, the inclination of the ultrasonic beam with respect to the entry surface, and the performance characteristics of the test system may cause either a reduction of isolated indications or a substantial loss of back reflection and thereby could seriously impair the reliability of the test procedure outlined in this standard. 4.2 Accurate evaluations of discontinuity size also may be limited significantly by variations in beam characteristics which exist in most search units. For this reason, discontinuity size as determined by the test procedure outlined in this method is regarded as “apparent” or “estimated” in recognition of the limited quantitative value of the measurement. 4.3 Because a large number of interacting variables in a test system can adversely influence the results of an ultrasonic test, the actual quantitative effects of detected discontinuities upon the mechanical properties of the inspected plate are difficult to establish. Consequently, this ultrasonic inspection method is not applicable as an exclusive indicator of the ultimate quality and performance of pressure vessels but provides a reliable control of plate quality to avoid failure during the forming process for fabrication of vessels.