基于磁各向异性的铁磁构件残余应力磁测理论与方法研究  

Study on the magnetic measurement theory and method of residual stress for ferromagnetic components based on magnetic anisotropy

作　　者：辛伟[1] 梁琳[1] 丁克勤[1] 赵禹 王洪柱[1] Xin Wei;Liang Lin;Ding Keqin;Zhao Yu;Wang Hongzhu(China Special Equipment Inspection and Research Institute,Beijing 100029,China;Testarc Technologies Co.,Ltd.,Beijing 100029,China)

机构地区：[1]中国特种设备检测研究院,北京100029 [2]北京中检希望科技有限公司,北京100029

出　　处：《仪器仪表学报》2020年第11期137-146,共10页Chinese Journal of Scientific Instrument

基　　金：国家重点研发计划(2018YFF0214701);中国特种设备检测研究院内部科研项目(S2019MK334)资助。

摘　　要：残余应力广泛存在于铸造、切削、热处理、焊接等处理后的结构件内,会对材料的物理、力学性能产生很大影响,对结构的强度造成很大危害,但残余应力的准确、快速检测较为困难。由于铁磁构件内的残余应力会引起材料磁导率的变化,导致构件呈磁各向异性,所以利用磁各向异性研究铁磁构件残余应力的准确、快速检测具有实际意义。首先基于磁路理论,建立了九极磁传感器等效磁路,并根据检测线圈的绕制特点,将九极磁传感器分为两个五极传感器进行分析。然后加载正弦电压,考虑被测构件的磁化状态,再利用分割磁场法求解空气隙磁阻,推导了九极磁传感器磁测残余应力理论模型,得到了系数K的数学表达式,该表达式揭示了系数K与传感器尺寸、线圈匝数、励磁电流以及空气隙之间的关系,可用于九极磁传感器尺寸和励磁电流参数的优化。最后绕制九极磁传感器,构建应力磁测试验平台,对残余应力磁测理论模型的准确性进行了验证。多组试验结果表明,不同应力作用下,理论与试验结果一致,主应力差的绝对误差基本在5 MPa以内,最大主应力方向角绝对误差基本在3°以内,磁测重复性较好,能够为铁磁构件残余应力的准确、快速检测提供理论基础。Residual stress widely exists in the structural parts after casting, cutting, heat treatment, welding and other treatments, which will have a great impact on the physical and mechanical properties of the material, and cause great harm to the strength of the structure. However, it is difficult to detect the residual stress accurately and quickly. Since the residual stress in ferromagnetic components can cause the change of material permeability and lead to the magnetic anisotropy of the components, so it has practical significance using the magnetic anisotropy to study the accurate and rapid detection of the residual stress in ferromagnetic components. In this paper, the equivalent magnetic circuit of the nine-pole magnetic sensor is established based on the magnetic circuit theory. According to the winding characteristics of the detection coil, the nine-pole magnetic sensor is divided into two five-pole sensors for analysis. Then, the sine voltage is loaded, the magnetization state of the component is considered, the magnetic field segmentation method is used to solve the air gap magnetic resistance, the theoretical model of the residual stress for nine-pole magnetic sensor is derived, and the mathematical expression of the coefficient K is obtained. The expression reveals the relationship between coefficient K and the sensor size, number of turns of the coil, the exciting current and the air gap, which can be used to optimize the size and exciting current parameters of the nine-pole magnetic sensor. Finally, a nine-pole magnetic sensor was wound, and a stress magnetic testing platform was built, which were used to verify the accuracy of the theoretical model for the residual stress magnetic measurement theory. The results of groups of experiments show that the theoretical results agree with the experiment results under different stress conditions. The absolute error of the principal stress difference is basically within 5 MPa, the absolute error of the maximum principal stress direction angle is basically within

关 键 词：残余应力 磁各向异性 九极磁传感器 磁路模型 主应力差 差分感应电压 

分 类 号：TH87[机械工程—仪器科学与技术] TG115[机械工程—精密仪器及机械]