Research On Micromagnetic Multiparameter Stress Measurement Method For Magnetic Anisotropic Materials

Ferromagnetic materials,as widely used engineering materials,play a vital role in many areas of people's livelihood,such as railways,natural gas,oil pipelines,hoisting machinery,large steel structures,amusement facilities and large bridges,etc.It is an important infrastructure for economic construction and people's lives.The safety issues of such large-scale equipment in the operation process are related to people's lives,property,and economic problems,and cannot be missed.Therefore,early damage detection of large-scale equipment is a key step to avoid major accidents.occur.Especially for pipeline steel materials often used in oil and gas transmission projects,because of their typical magnetic anisotropy,there are many uncertain factors when using electromagnetic methods for non-destructive evaluation,resulting in inaccurate test results.Therefore,how to accurately characterize the stress state of anisotropic materials is very important in engineering applications.In this subject,the multi-parameter stress detection method based on micro-magnetic is studied.Micromagnetic multi-parameter detection technology integrates magnetic Barkhausen noise(MBN),incremental permeability,tangential magnetic field intensity harmonic analysis,multi-frequency eddy current and other electromagnetic detection methods.Features have developed rapidly in the performance evaluation of ferromagnetic materials,and are favored by the majority of engineering sites.In previous studies,MBN technology has been proved to be a convenient,accurate and non-destructive method to measure the surface stress of ferromagnetic materials,but most of the above studies are based on magnetic isotropic materials.Magnetic anisotropic material surfaces are not applicable,and the accuracy rate is reduced.Based on the above problems,this paper adopts the magnetic multi-parameter detection method to establish a quantitative microstructure relationship with the material surface by analyzing various characteristic parameters extracted from various electromagnetic signals,and then study a more effective method for detecting and evaluating the surface stress of magnetically anisotropic materials.Aiming at the problem of inaccurate detection on the surface of magnetocrystalline isotropic materials by researching and detecting methods on the surface of magnetocrystalline isotropic materials,in order to find out the reason for this inaccuracy,the magnetic Buckhao of magnetocrystalline anisotropic materials was experimentally studied.The distribution characteristics of Sen noise,revealing the different magnetic anisotropy distribution in different positions of the same material from three aspects: the direction of the difficult and easy magnetization axis,the magnitude of the magnetization direction,and the shape factor that characterize the magnetic anisotropy characteristics of the material.uniform phenomenon.Aiming at the problem of inaccurate stress detection and evaluation due to the uneven distribution of MBN signals on the surface of magnetocrystalline anisotropic materials based on magnetic Barkhausen noise based on a single electromagnetic detection technology,a micromagnetic multi-parameter detection method is proposed to measure the magnetocrystalline anisotropy.Material surface stress characterization.First,the principle and method of eigenvalue extraction of four electromagnetic detection technologies of micromagnetic multi-parameter are analyzed and studied,and the corresponding eigenvalues are briefly explained,and then different eigenvalues of micromagnetic multi-parameter are analyzed.Correlation with stress,the analysis shows that most of the eigenvalues have a moderate or above correlation with stress,which can be used to characterize the stress state assessment of the surface of magnetocrystalline anisotropic materials using a multi-parameter fusion method.Based on the above experimental research basis,in order to more accurately characterize the surface stress state of magnetic anisotropic materials,a micro-magnetic multi-parameter fusion stress detection technology is proposed.Change relationship,establish a multiple linear regression model,and predict the stress value of the principal stress direction at the measurement point in four cases where the magnetic easy axis and the tensile direction are 0°,30°,60°,and 90°.When the maximum relative error is greater than 40 MPa,the maximum relative error is less than 10%,which greatly improves the accuracy of the non-destructive testing method for evaluating the surface stress of magnetocrystalline anisotropic materials.