Metal magnetic memory phenomenon of high-strength steel in the process of grinding

The phenomenon of metal magnetic memory (MMM) of high-strength steel such as gun steel and projectile steel in the process of grinding was discussed in this paper. Experimental data show the remarkable change of magnetic field intensity in the specimen's surface. But the change is non-linear, and further study is needed. Comparing the test results of MMM with the stress change tested by means of X-ray diffraction, certain rules have been found from the contrast of the two. These phenomena are explained from the point of view of materials science, and the model of the relation between the tested magnetic field intensity and stress-gradient of cylindrical parts has been set up in the view of the magneto-elastic theory.