油气管道不等壁厚内锥孔环焊缝的相控阵超声检测

PAUT for conical inner groove girth weld of oil and gas pipelines with unequal wall thickness

油气输送管道建设中,不等壁厚钢管的焊接较为常见。传统倒角式内坡口环焊缝的根部应力集中、焊趾易存在缺陷且容易漏检。孔锥形内坡口环焊缝可将不等壁厚焊接改进为等壁厚焊接。围绕油气管道常用的PAUT检测,针对孔锥形内坡口引起的检测质量问题进行了理论(仿真)分析,设计加工了含不同位置缺陷的对比试块并结合仿真试验进行了对比分析,确定了适宜的最小锥孔长度,为工程应用提供了有力的技术支持。

In the construction of oil and gas transmission pipelines,welding of steel pipelines with unequal wall thickness are common.The traditional fillet inner groove girth weld exists adverse effects such as root stress concentration,weld toe defects and miss test can realize equal wall thickness welding for connection of unequal wall thickness.Focusing on the PAUT test commonly used in oil and gas pipelines,in this paper,theoretical(simulation)analysis on the test quality problems caused by the conical inner groove was carried out,design and machining of the test block with different positions of defects was achieved,simulation and comparative analysis on this block was investigated.Finally,the appropriate minimum conical hole length was determined for providing strong technical support for engineering applications.