论文部分内容阅读
提出结合衍射渡越时间方法和脉冲回波方法的超声波焊缝裂纹原位检测方法，对裂纹缺陷的位置与尺寸参数进行了定量无损估计。克服了衍射渡越时间方法难以对近焊件表面裂纹缺陷进行检测的弱点，也避免了为估计裂纹位置而进行的ｘ轴扫描，提高了对焊缝的检测效率。分析了影响方法分辨率和准确度的各种因素，并采用中心频率为 １５ ＭＨｚ的检测超声波对钢板焊缝中不同位置和尺寸的裂纹进行了检测，试验结果证实该方法能够准确估计尺寸小到２ｍｍ的焊接裂纹。
The method of diffraction time-of-flight and pulse echo method was proposed to detect the crack location in the weld and the dimension parameters of the crack were quantitatively and non-destructively estimated. The method overcomes the defect that the diffraction transit time method is difficult to detect the surface crack defect of the near weldment and also avoids the x-axis scan for estimating the crack location, thereby improving the detection efficiency of the weld. Various factors that affect the resolution and accuracy of the method were analyzed. The detection of cracks in different positions and sizes in the weld of the steel plate was carried out by using the detection ultrasonic wave with a center frequency of 15 MHz. The experimental results show that the method can accurately estimate the size of small 2mm weld crack.