应力腐蚀裂纹的超声检测和定量——相控阵超声（PAUT）技术应用案例

介绍欧美国家用相控阵超声（PAUT）对应力腐蚀裂纹进行检测和定量的案例。检测和定量的应力腐蚀裂纹，高为3mm～15mm，存在于下列工件中：壁厚9mm的焊缝、螺栓（裂纹深度位置分别为22ram和59mm）、汽轮机叶片根部、转子轮缘叶根槽。另外，也应用于应力氢致裂纹的检测，对其作了测高评定。还与断口试验结果作了对比。PAUT对裂纹的测高精确度，能控制在±1mm，有测定值偏小的倾向。最后，提出有关优化测量应力腐蚀裂纹端部分支状态的PAuT参数的建议。介绍国外PAUT应用案例的目的，为国内特别是承压设备行业如何参照ASME法规最新版（2011a）积极推广应用PAuT提供有用借鉴。

Case Studies:Using Phased Array Ultrasonic Technology to Detection and Sizing of Stress Corrosion Cracks

The paper presents case studies related to stress corrosion cracks(SCC) detected and sized by Phased Array Ultrasonic Technology(PAUT).SCC with height between 3 mm to 15 mm were detected and sized in the following components: welds with thickness of 9 mm,bolts at depth 22mm and 59mm,blade roots,rotor steeple hook.A stress oriented hydrogen-induced crack is also displayed and height evaluation is estimated.Comparison with fracture mechanics,grinding measurement and optical is also presented.PAUT is capable to size cracks within ± 1 mm,with an under sizing trend.Technical recommendations are also made for optimizing the PAUT parameters in sizing the last significant tip(branch) of SCC. The intention of introducing these cases related to PAUT is to provide a useful reference to promoting further the use of PAUT at home,especially in the pressure equipment industry in accordance with the requirements of the recent ASME Code(2011a).