热处理方式对残余磁场强度的影响

Study on effect of heat treatment on residual magnetic intensity

为了解不同热处理方式下铁磁材料的残余磁场强度变化规律,分别在弹性和塑性变形阶段对其进行了单轴拉伸试验。结果表明,在弹性阶段,随着拉伸载荷的增加,残余磁场强度和标准差都是减小的。在同一拉伸载荷作用下,调质热处理试样的残余磁场强度最大,退火试样次之,无热处理试样的最小;在塑性变形的初始阶段,试样表面的残余磁场强度没有规律可循。当塑性变形较大时,试样表面各点处的残余磁场强度幅值波动很小,其均值和标准差几乎不再变化。可以根据铁磁材料残余磁场强度和标准差的变化情况判断其是否承受过冲击载荷或大载荷,是否发生了塑性变形。

In order to find the variation law of the residual magnetic intensity of ferromagnetic material processed by different heat treatment, which is under external load, axial tension tests are completed in elastic deformation and plastic phase. The experimental results indicate that the residual magnetic intensity and its standard difference decrease gradually along with the increase of the tensile load in elastic deformation phase, and in this process the residual magnetic intensity of the tempering sample is the biggest, the annealed specimen is less and the sample without any heat treatment is the least; At the beginning of plastic phase, the residual magnetic intensity variation is inordinate. When the increasing of residual deformation is bigger than one value, the residual magnetic intensities of the points on sample surface fluctuate very little, their mean value and standard difference nearly do not change. So by getting the mean residual magnetic intensity and their standard difference, the plastic deformation of ferromagnetic material can be identified, due to impact load or great load.