Research On Force-Magnetic Effect Of Ferromagnetic Specimen Based On Metal Magnetic Memory

Metal magnetic memory testing technique can be detected effective material stress concentration region, the material can be used for early diagnosis to prevent the subsequent use of the accident. This paper combine basic materials, physics and the theory of metal magnetic memory, used the simulation mode and mechanical test,explored research the specimen of the ferromagnetic metal magnetic memory based on the force- magnetic effect.By simulating 20# steel, verified that the surface tangential component and the normal component of metal magnetic memory testing technique can detect tangential stress concentration in the specimens at different pulling force on the weight of the component to the component and the data processing method, by the area of Lissajous to determine the stage stretch material quantitatively. This metal magnetic memory testing technology can provide the basis for quantitative detection.20 # steel fatigue damage test research on the different gaps found metal magnetic memory testing technology for material stress concentration regions of different gap for effective detection; the characteristic parameters and crack of magnetic memory signal correspond to each other in the expansion phase, magnetic memory signal can characterize the extent by characteristic parameters, there is a relationship in crack propagation material, quantity and characteristics of damage parameters between the magnetic memory can be used to characterize the degree of signal feature fatigue damage process.In Q235 low carbon steel to reverse the magnetization reversal of the trial, found that when the torque T after reaching or exceeding the yield torque(39.98 N ? m), the magnetic induction B in the torque T obviously existed magnetization reversal effect; by analyzing the leakage magnetic field intensity at different stages of the corresponding changes of the maximum magnetic induction △Bmax and torque T in the law and the characteristics variation of the maximum magnetic induction △ Bmax and torque T to pretest the twisting force in which stage. Torsion test to reverse the magnetization reversal process of the force-magnetic relationship made a simple evaluation for subsequent MMM to do the groundwork in a torsion test analysis.For the 20 #, 45 # and Q235 steel,study of different types of steel stretching test,found three steels under tension, the magnetic induction B and the change of hardness are the same law, regardless of the type of steel; plastic deformation was detected in the magnetic induction B is gradually decreased, and the hardness is gradually increased,contrary to that of the two. Close hardness of the material and the magnetic induction B,the hardness can be used of contact the magnetic force relationship. Subsequent force-Magnetic test can serve the hardness as an entry point.