Abstract: Grooves and round corners of ring forgings used in aeroengine casing were prone to produce various defects. Taking the curved surface structures of aeroengine casing rings as an object， the ultrasonic TFM detection and defect quantification were proposed. The testing areas were divided into grid points in cylindrical coordinate system and the reference blocks with 0.8 mm artificial defects were designed. The maximum amplitude defect data set at all grid points was collected. The data set was fitted in two directions of depth and angle， and the distance angle amplitude surface defects quantitative evaluation method was established. The experimental results of a casing ring specimen show that the errors of quantitative method are less than 1 dB. 

Key words: aeroengine, ring forging, curved surface, total focusing method（TFM）, defect quantification

摘要： 航空发动机机匣所用环形锻件的沟槽和圆角部位容易产生各类缺陷。针对环形锻件的曲面结构，提出了超声全聚焦检测与缺陷定量方法。在待测区域建立圆柱坐标系并划分网格点，设计了0.8 mm当量缺陷对比试块，采集了网格点处缺陷最大幅值数据集，将数据集在深度和角度两个方向拟合，建立了距离-角度-幅值曲面缺陷定量评价方法。某机匣环件试样实验结果表明缺陷定量方法的误差小于1 dB。

关键词: 航空发动机, 环形锻件, 曲面, 全聚焦法, 缺陷定量化