The simulated CSP process tested Cu-bearing high magnetic induction oriented (Hi-B) steel (/% : 0. 06C

3. 38Si

0. 14Mn

0. 013P

0. 003S

0. 37Cu

0. 019Als

0.0087N) is melted by laboratory 15 kg vacuum induction furnace

cast to 60mm x 120mm slab and hot-rolled by 5 passes to 3. 95 mm plate with finishing rolling temperature 870 °C. The effect of direct water-quenching (after rolling water-quenching at 870℃ ) and stepped cooling ( after rolling water-quenching at 870℃ to 580℃ then air-cooling) process on precipitation of inhibitors at surface layer and center of hot-rolled plate has been studied. Results show that the main inhibitors precipitated in hot-rolled plate are Cu

2

S spherical particles with some MnS etc ； the amount of inhibitors precipitated at surface layer of hot-rolled plate is less than that precipitated at center of plate

but the average size of inhi

bitors is larger than that at center； and the size of precipitated inhibitors in steel plate by stepped cooling process is larger than the size of precipitated inhibitors in steel plate by direct water quenching process.