钻具壳体断裂分析与试验评价  

Fracture Analysis and Test Evaluating of Shell of Drill Tool

作　　者：姜海翔[1] 郝军[2] JIANG Hai-xiang;HAO Jun(Jingchu University of Technology,School of Mechanical Engineering,Hubei Jingmen 448000,China;Jianghan Machi-nery Research Institute of CNPC Drilling Engineering Institute of Technology,Hubei Jingzhou 434000,China)

机构地区：[1]荆楚理工学院机械工程学院,湖北荆门448000 [2]中国石油集团钻井工程技术研究院,江汉机械研究所,湖北荆州434000

出　　处：《机械设计与制造》2019年第12期59-62,共4页Machinery Design & Manufacture

基　　金：荆门市科技局研究项目(YDKY2017004);深层连续管作业装备项目(2016ZX05023006-001)

摘　　要：为了研究Φ216万向轴壳体特殊锥度螺纹断裂失效原因,分析连接处螺纹的应力状态,根据壳体连接螺纹的有限元计算方程,建立一种特殊锥度螺纹的力学模型,采用了有限元方法对其进行计算,并结合上扣扭矩试验测试,进行了螺纹表面的损伤分析。结果表明:(1)在井斜曲率30°/100m和扭矩为25 kN·m的组合载荷作用下,在第一牙与第二牙牙底处螺纹主应力已经达到或接近屈服强度极限,此处与万向轴壳体的实际断裂部位对应;(2)壳体螺纹连接部分的上扣扭矩过大,超过扭矩值的标准;(3)加热方式拆卸会给螺纹部分附加一次调质处理,影响螺纹部位的晶相组织,使材料韧塑性会变差,表面损伤造成缺口,引起螺纹表面裂纹扩展,这些因素都会增加螺纹部位的疲劳断裂风险。In order to study the fracture failure of special taper thread of Φ216 universal shaft shell,analyze the stress condition of connection thread,according to the finite element equation of shell connecting thread,set up the mechanical model of a kind of special taper thread,the finite element method is used to simulate,combined with the torque test,carry out analysis of thread surface damage.The results show that:(1)Under the conbined load of 30°/100m and 25kN·m,the main stress has reached or closed to the yield strength limit at the bottom of the first teeth and second teeth of thread,where is corresponds to the actual fracture position of universal shaft shell;(2)The makeup torque of connection thread part is too large,which is exceed the makeup torque value standard;(3)Heating disassembly will give additional tempering of threaded location,which influences the phase organization of material,and the surface toughness of thread will become worse,increases the brittleness risk of thread,the notch of thread will be caused by surface damage,which leads to crack propagation of thread surface,and it will increase the risk of fatigue fracture of thread.

关 键 词：万向轴壳体 断裂 有限元 上扣扭矩 晶相组织 

分 类 号：TH16[机械工程—机械制造及自动化]