论文部分内容阅读
为了保证组对和焊接质量,超临界电站锅炉集箱和管道的环向对接焊接接头需要在内表面进行削薄倒角处理。现场常规超声波检测时,个别情况下在倒角对应厚度之前会出现倒角异常回波,较易造成检测人员的误判。通过模拟现场情况,加工不同角度的倒角试块,并进行常规超声波检测数据对比和计算,结果表明:异常倒角回波是超声波主声束轴线下方扩散声波传播到内表面倒角斜面时产生几何反射,且几何反射满足横波斜入射角度<10°时,特别是扩散声波在斜面处横波斜入射角接近0°时产生。
In order to ensure the quality of the group and the welding quality, the butt-welded joints of the header and the pipe of the supercritical power plant boilers need to be chamfered and chamfered on the inner surface. On-site conventional ultrasonic testing, in some cases, chamfering before the corresponding thickness of the chamfer will appear abnormal echo, the more likely to cause the detection of false positives. By simulating the scene, the chamfering test block with different angles was machined and compared with the conventional ultrasonic testing data. The results show that the abnormal chamfer echo is generated when the diffuse sound wave below the axis of ultrasonic main beam propagates to the chamfer of the inner surface Geometric reflection, and the geometric reflection satisfies the oblique incident angle <10 °, especially when the diffuse sound wave is incident at an oblique incident angle near 0 ° on the inclined plane.