Analysis of Grain Growth and Magnetic Properties in IF Steel after Strain Annealing

摘要

The effects of the grain size on the magnetic properties in IF steel after strain annealing were investigated. A 92.5 percent cold rolled and annealed IF steel sheet was temper rolled by 0.4 percent reduction in thickness and subsequently strain annealed at the temperature ranging between 670 deg C and 950 deg C for various time periods. The grains after strain annealing became more coarse than those after primary annealing. The grains were coarsened due to the strain induced grain boundary migration(SIGM). It was found that the permeability increased and coercivity decreased with the increase of grain size. The optimum magnetic properties was achieved after strain annealing at 850 deg C for 30 mm. Under this condition, the coercivity was measured to be 0.6Oe and the maximum permeability was 13000, also found that the optimum grain size was 83 mu m.