In this paper,the purpose of high-speed railway train wheel safety detection is to study the application of metal magnetic memory detection method in early detection of wheelset faults.The key research content is the force-magnetic effect of the wheel-pair material 25CrMo4 alloy structural steel of the "Harmony" high-speed train.According to the theory of magnetic physics,metal magnetization and thermodynamics,the internal energy variation of alloy steel is analyzed and the magnetization model of metal forcemagnetic effect is established.Taking 25CrMo4 steel as the research object,the quasi-static tensile test of nonstandard size samples under different loads was carried out,and the on-line measurement of the leakage magnetic field on the surface of the sample and the measurement of the surface leakage magnetic field after different degrees of stretching and unloading were carried out..At the same time,the stress finite element simulation of the plate model with the same size as the sample was carried out,and the Ansys numerical simulation results were compared with the magnetic field measurement results.The results show that in the tensile test,the leakage magnetic field value in the middle of the test piece changes gently and evenly when the load is small,and the magnetic memory signal increases sharply near the edge position,which is the same as the final yield position.It is feasible to evaluate the stress concentration of ferromagnetic components by magnetic memory method.From the spectrum point of view,through spectral analysis of simulation and experimental data,the relationship between spectral characteristics and stress of magnetic memory signals is explored.The magnetic memory signal is highly anti-interference and convergence.This special feature provides great convenience for railway vehicle safety detection.The spatial interpolation method is used to expand the limited magnetic memory signal and stress relationship map,and the position-stress-magnetic field strength is established.Multiphysics multi-dimensional data matrix can realize stress back-off at any position and also realize magnetic signal localization under arbitrary stress.The conclusions obtained above are expected to help expand the scope of application of magnetic memory detection technology,provide theoretical basis for the early evaluation and evaluation criteria of 25CrMo4 alloy structural steel,and provide a basis for on-line detection of high-speed train wheel safety reference. |