近两年来 ,焊缝超声 TOFD法 (衍射时差法 )已在欧、美、日等国得到越来越多的实际应用。国内尚未有动静。介绍国外在这方面的基础试验动态 ,概述有关原理、装置、方法及缺陷定性、定量、定位的要决 ,企望此技术在国内锅炉、压力容器及结构件焊缝超声检测上发挥重要作用。 Over the past two years, the ultrasonic TOFD method (diffractometry) has been more and more practical applications in Europe, the United States, Japan and other countries. There is no movement in China. This paper introduces the basic experimental developments abroad, summarizes the principles, devices, methods and the determination of qualitative, quantitative and positioning defects. It is hoped that this technique will play an important role in ultrasonic testing of domestic boilers, pressure vessels and structural welds.