油管螺旋副失效分析及预防措施

Tubingthreads failure analysis and countermeasures.

油管与接箍连接处螺旋副的主要失效形式为螺纹磨损及塑性变形或断裂 ,螺纹磨损是多种磨损机理综合作用所致 ,螺纹牙塑性变形或断裂是由于在液压动力钳拧紧力矩的强制作用及其它载荷的影响下 ,螺纹牙现有硬度及强度不够而产生的。对螺纹进行表面感应淬火强化处理以增加其硬度 ,可同时提高其耐磨性和强度 ,防止螺旋副失效。对油管上扣时的情况进行了力学分析 ,建立了螺纹硬度计算公式 ,计算硬度值可作为淬火强化处理时的参考值。

The main failure patterns of the tubing threads are the wear and plastic deformation or fracture of the threads.The wear mechanism of the tubing threads is analyzed, and countermeasures are presented, including reducing the surface roughness, applying coats and surface induction quenching. The plastic deformation or fracture of the tubing threads is caused by the screwing torque of the power tongs and the action of other loads, the countermeasures are aligning the tubing and the couplings and improving the hardness of the threads by surface induction hardening. The equation for calculating the hardness of the tubing threads is presented, which can be used for calculating the hardness value in surface hardening.