油气管道用埋弧增材三通的性能研究

Study on Performance of Submerged Arc Additive Tee for Oil and Gas Pipeline

采用埋弧增材制造技术成功制造出尺寸为Φ1219 mm×55 mm的油气管道用低温三通,研究了增材三通的微观组织与力学性能。结果表明:显微组织以细小的针状铁素体为主;增材三通的硬度和拉伸性能在不同位置和不同方向上不存在各向异性;冲击韧性在不同位置基本无差别,但在不同方向上存在各向异性。垂直打印方向的冲击试样主要受韧性断裂控制,而平行打印方向的冲击试样主要受脆性解理断裂控制。利用EBSD技术分析了不同强化机理对屈服强度的贡献,细晶强化的贡献占比约为50%;垂直打印方向试样中大角度晶界占比高于平行打印方向,表现为相对较高的冲击韧性。

A low-temperature tee with the size ofΦ1219 mm×55 mm for oil and gas pipelines was successfully fabricated by submerged arc additive manufacturing technology.The microstructure and mechanical properties of the additive tee were studied.The results show that the microstructure is mainly fine acicular ferrite,and the hardness and tensile performance of the additive tee are isotropic in different locations and directions,while the impact toughness is basically the same in different locations,but anisotropic in different directions.The impact samples in the samples in the vertical printing direction are mainly controlled by ductile fracture,while the impact samples in the parallel printing direction are mainly controlled by brittle cleavage fracture.The contribution of different strengthening mechanisms to yield strength is analyzed using EBSD technology,and the contribution of fine grain strengthening accounted for about 50%.The proportion of high angle grain boundary in the samples in the vertical printing direction is higher than that in the parallel printing direction,which shows a relatively high impact toughness.