燃气轮机透平叶片数字射线检测分区及透照参数确定方法

The traditional digital radiography methodology of defect detection has many shortcomings, such as inappropriate partition, low efficiency and missed detection. A method for determining partition and exposure parameters of gas turbine blades based on digital radiography is presented. The relationship between projection area of blades and turntable rotation under the condition that the design model is unknown is obtained by an approximation algorithm. According to the relationship, the direction of illumination for blade detection is determined to make sure that the projection area is biggest. Choosing the focal length by analyzing the effect of focus length on the quality of radiographic images and the geometric parameters of radiographic equipment, the gray scale interval of linear response through the analysis of the response of flat panel detectors on different exposure is found out for determining the partitions of blades to make sure that the gray intervals of the radiographic images are in the gray scale interval of linear response, thus the inappropriate partition, low efficiency and the missed detection in the traditional method are avoided. The comparison experiments show that the gray value of partition 1 and 4 in the traditional method is too high and that of partition 4 and 5 is too low, which often leads to a missed detection, and the detection sensitivity of this method is higher than that of the traditional method except partition 4.