高压加热器管板与筒体焊接接头是最终组焊接头，接头结构形状复杂，焊接难度高，易产生未焊透、裂纹等缺陷，采用超声反射法检测时受限于结构影响，只能进行底部直射检测，而底部状况会干扰缺陷的识别。通过试验分析工件规格形状对相控阵超声检测技术缺陷检出能力的影响，提出超声衍射时差法与相控阵超声组合检测的方法，确保接头覆盖，结合相控阵三维显示识别技术排除干扰，对今后开展类似焊接接头检测具有指导意义。

High pressure heater tube plate and cylinder welding joint is the final group of welding joint. The joint structure is complex and is easily susceptible to the lack of penetration. It is therefore likely to produce non-welded joint and cracks. At the same time the effectiveness of using reflection ultrasonic detection is limited by the structure influence and it can only carry on the bottom direct detection due to that the bottom condition interferers with the identification of defects. Through experimental research on the effect of workpiece size and shape on the detection ability of phased array ultrasonic, the combination of time difference ultrasonic diffraction method and phased array ultrasonic test was put forward to ensure the joint coverage. The structure identification by phased array ultrasonic inspection can also be combined to eliminate interference, which has guiding significance for similar welding joint detection in the future.