基于金属磁记忆效应的钻机起升滑轮无损检测

摘要

Under the effects of loads and Earth's magnetic field, orientations of the magnetic domain in stress concentration and damage zones of the lifting pulleys will be changed. This change will be maintained even the loads are removed. This causes new magnetic field produced in those areas and magnetic flux leakage happening on the surface of those places. By testing the grads of the leaking magnetic field, the magnetic factor m was calculated. Compared m with mmax of the material, the level of the stress concentration was determined. Here, techniques using metal magnetic memory to do nondestructive testing of the lifting pulleys of the drilling rigs are studied.%钻机起升滑轮在受力和地球磁场的共同作用下,应力集中区域和缺陷表面会产生微弱的磁场泄漏现象,这种微弱的漏磁场具有定向和不可逆的特性,且不会因为外界受力的消除而消失.对滑轮表面漏磁场强度变化率进行检测,计算滑轮磁参数,并比较与其材料磁参数的关系,确认滑轮应力集中的程度.介绍了基于金属磁记忆效应的钻机起升滑轮无损检测技术及其应用.