45CrNiMoVA钢脉冲磁处理的强化机理

Understanding the mechanism of the effects of magnetization treatment on the mechanical properties of materials for applications in magnetic field-assisted machining and magnetic treatment strengthening is of great significance. Pearlite and tempered martensite 45CrNiMoVA steels were magnetized by a pulsed magnetic field. Nanoindentation experiments were conducted to examine the effects of a pulsed magnetic field on the residual stress, hardness, and elastic modulus. The effect of pulsed magnetic treatment on the microstructure of the magnetic domain was analyzed by measuring the hysteresis loop and via magnetic microscopy. A magnetic pulse treatment could increase the residual compressive stress on the sample surface. The hardness of pearlite and tempered martensite 45CrNiMoVA steel was increased by 1.85% and 1.84%, respectively, after the magnetic pulse treatment. The magnetic pulse treatment had an insignificant effect on the elastic modulus of pearlite 45CrNiMoVA steel but had a considerable effect on tempered martensite 45CrNiMoVA steel. After the magnetic pulse treatment, the elastic modulus of the tempered martensite 45CrNiMoVA steel increased by 4.48%. In the magnetization process, the stress and strain of the micro-region material caused by the movement of the magnetic domains was the main mechanism responsible for strengthening the mechanical properties of 45CrNiMoVA steel.