为避免常规超声A波锯齿型扫查方式检测管道对接焊口的横向裂纹时可能造成的漏检和误判，采用骑焊缝式A波一次反射波扫查方式进行检测，较好地解决了这一问题。较平行于焊接面的锯齿型扫查，骑焊缝式扫查更易检测到横向缺陷，同时，通过计算可校正由于管道弧度的原因而产生定位误差，校正后的数据与原始结果相符。对于发电厂大口径厚壁管道焊口的横向裂纹检测，骑焊缝式检测是一种积极、有效的方法。

The method of sawtooth pattern detection mode by common ultrasonic A wave applying to test crosswise crack of pipe welded joint might cause possibility of omission and misjudge. To prevent this from happening, the method of across welded joint mode by ultrasonic first reflection wave solved the problem preferably. Comparing with sawtooth pattern mode of paralleling with face of weld, the method of across welded joint mode can test existence of crosswise crack more easily, and the error of position caused by pipe radian can be corrected by calculation, the correction data corresponded to the original results. It is a positive and effective method of across welded joint mode for testing crosswise crack of thick walled heavy-caliber pipe welded joint in power plant.