摩擦焊接式全钛合金钻杆焊区性能评价与研究

Performance Evaluation and Research of Weld Zone for Friction Welded All Titanium Alloy Drill Pipe

为了确保摩擦焊接式全钛合金钻杆管体与接头连接可靠,防止钛合金钻杆在钻进过程中出现焊缝断裂失效,对钛合金钻杆摩擦焊接工艺进行了研究。采用金相组织分析、硬度测试、拉伸试验、夏比冲击试验、旋转弯曲疲劳试验,对钛合金钻杆焊区材料进行性能分析与评价。结果显示,焊区材料金相组织为典型的双态(层片状α+β)组织,晶粒度13.0级;焊区材料强度达到130 ksi以上;平均冲击韧性值达到45.2 J,冲击韧性值无明显波动;试样在室温空气环境中承受362 MPa弯曲载荷条件下旋转周数均超过107次,失效形式为韧性断裂。研究表明,材料焊区整体性能可满足钻井现场使用要求。

In order to ensure the reliable connection between the pipe body and the joint of friction welded all titanium alloy drill pipe and prevent the weld fracture failure of titanium alloy drill pipe during drilling,the friction welding technology of titanium alloy drill pipe is studied.The research on friction welding process of titanium alloy drill pipe,the properties of titanium alloy drill pipe welding zone material were analyzed and studied by metallographic analysis,hardness test,tensile test,Charpy impact test and rotary bending fatigue test.The results show that the microstructure of the weld zone material is typical dual state(lamellarα+β)structure with grain size of 13.0;the strength of the weld zone material reaches over 130 ksi;the average impact toughness value reaches 45.2 J,and the impact toughness value has no obvious fluctuation;in the ambient air at room temperature and atmospheric pressure the specimen rotates more than 107 times under 362 MPa bending load rotation cycles,and the fracture of the rotating bending fatigue specimen is ductile fracture.The overall performance of weld zone can meet the requirements of drilling site.