Effects of Stress on Magnetic Characteristics for 20 Cold Rolled Steel Component

The relationships of magnetization of end surface with different stresses of 20 cold rolled steel items were measured and residual magnetization of end surface and coercive force with different stresses were analyzed. It was indicated that when stresses were smaller than bend point of materials, residual magnetization of end surface and coercive force of materials produced by the fatigues and residual stresses for different stresses almost remained constant. However, when stresses were greater than bend point of the materials, residual magnetization of end surface and coercive force increased sharply. It showed that the properties of mutation for residual magnetization of end surface and coercive force could be used to detect stress concentration and load condition, providing a new research thought for magnetic nondestructive testing method.