中文摘要：

将超声水浸法和TOFD（超声衍射时差）法相结合的技术,应用于检测壁厚为9mm的管环焊缝。使用超声波仿真软件Wave3000对薄壁管环焊缝进行水浸TOFD检测的数值模拟,显示波源发射的纵波经水-钢界面折射后继续沿着界面的下表面传播,部分副瓣折射回水中被接收探头接收,检测时可将这个波称作水浸TOFD检测的直通波。再以新的直通波和底面回波为基准,对管环焊缝进行水浸TOFD实际检测。利用此方法,在对薄壁管环焊缝的实际检测中,达到了很好的检测精度,其绝对误差不超过0.2μs。

英文摘要：

This paper combines ultrasonic immersion method and TOFD technology, and applies it in the detection of 9 mm wall thickness pipe ring weld. First of all, the numerical simulation of immersion TOFD （I- TOFD） detection for thin walled pipe girthed weld numerical modeling was performed by finite element method using ultrasonic simulation software Wave 3000. The simulation shows that the longitudinal wave inspired by source after refraction in water-steel interface, continues to spread along under the surface of water-steel interface, and part of the side lobe goes back to the water again and is to be received by the receiving probe. We call the wave as the lateral wave of I-TOFD. Then, the new lateral wave and the bottom echo can be used as reference in actual detection, and the detection accuracy is very good and absolute error is less than 0.2 μs.