Structure and coercive force of low-carbon electric sheet after second cold rolling

Conclusions

• 1. The average grain size of electric sheet after final annealing varies with the reduction during second cold rolling — with small (insufficient) reductions the grain size remains unchanged, reaches its highest value in the critical range of reductions, and then decreases in the supercritical range.

• 2. With decreasing average grain size and polygonization the coercive force increases, and therefore the variation of the coercive force with reduction is the reverse of the variation of the grain size with reduction.

• 3. Low-carbon electric sheet with a coercive force not over 79.8 A/m should be produced by using second cold rolling with not less than critical reduction.

• 4. With increasing final thickness of the sheet and increasing aluninum concentrations the critical reduction is higher. Increasing the aluminum concentration broadens the range of insufficient reductions, while increasing the thickness broadens the precritical range of reductions.