微磁技术在残余应力检测中的应用研究

摘要

Micro-magnetic is a technique by which can evaluate stress concentration and degree of fatigue damage by testing the permeability of ferromagnetic components. The technique can reflect the stress changes in component precisely. In order to measure the permeability accurately, the high sensitivity testing platform and the algorithm between the signal and the permeability are setup. The results demonstrate that the permeability and micro strain of the material increase with the residual stress, but the size of the crystal is decreased.%微磁检测技术是通过对试样磁信号的检测,对试样的应力集中情况和疲劳损伤程度进行早期评估的一种新的检测手段. 该方法的使用可以正确反映待测试样应力的变化. 为了精确测量试样的磁信号强度,在研制了高灵敏度磁矢量探头检测的试验平台的同时,建立了检测信号与磁导率的关系算法. 试验发现:应力集中区域会导致其与周边的区域磁导率发生相应的差异,即随着试样中所存在的残余应力增加,采集得到的磁信号强度增大,且材料的微观应变变大,晶粒减小.