焊接接头典型缺陷的数字X射线尺寸测量技术

为了准确测量焊接接头典型缺陷的尺寸,提出了一种基于半波高法(HWH)的焊接接头缺陷数字射线尺寸测量技术。首先,分析了数字射线检测系统的调制传递函数(MTF),确定了检测系统的空间分辨率。其次,对焊接接头的典型缺陷进行模拟,通过半波高法测量其尺寸。结果表明:依据瑞利判据,运用双丝像质计测定该检测系统的空间分辨率为4.5 Lp/mm;运用该方法测量焊接接头缺陷尺寸,与实际尺寸基本相符,误差小于6.3%,该方法避免了人为因素的影响,精度可满足日常产品的检测需求。

Digital X-Ray Size Measurement Technology for Typical Defects of Welding Joint

This paper presents a new digital X-ray testing technology for welding joint defects based on half wave height method (HWH) in order to ensure the measurement accuracy of the size of the defects. First, the MTF of the digital X-ray testing system is analyzed and the spatial resolution of the system is confirmed. Furthermore, the typical defects of welding joints are simulated, and the size of these defects is measured using HWH. The results are as follows:(1)based on Rayleigh criterion, the spatial resolution of the X-ray testing system is 4.5 Lp/mm determined by the double wire image quality indicator; (2)the measured sizes of the welding joint defects agree with the actual sizes, and the measuring errors are within 6.3%, thus, the influence of human factor can be avoided using the HWH method, and the accuracy can satisfy the testing requirements of conventional products.