核电站反应堆钢制安全壳是防止反应堆放射性物质进入外界环境的最后一道屏障，对核电站的安全运行至关重要。主要介绍了在不去除焊缝表面余高的情况下，相控阵（PAUT）和衍射时差法（TOFD）超声检测技术在钢制安全壳对接焊缝中的检测应用。通过在埋藏有一定数量的典型焊接缺陷的模拟试块上的试验表明：相控阵和衍射时差法超声检测技术对焊接缺陷具有较高的检出率和较强的缺陷定位、定量的能力，是一种可靠、高效及经济的检测手段。

The steel containment shell of nuclear power plant is the last barrier to prevent radioactive material from entering the exotic environment. It is very important for the safe operation of nuclear power plant. This paper mainly introduces the application of PAUT and TOFD ultrasonic testing technology to the detection of butt welds of steel containment shells with the weld reinforcement. The experimental research on the simulated test block with a certain number of typical welding defects has proven that the detection of welding defects by PAUT and TOFD ultrasonic testing shows a high detection rate, strong localization and quantitative ability. It is a reliable, efficient and economical means of inspection.