| Title |
Prevention of Rolled-in Defects in Cold-Rolled Ultra-Low Carbon Steels |
| Authors |
류재화(Jae Hwa Ryu) ; 류한빈(Han Bin Ryu) |
| Abstract |
The cause of the surface defect in the cold-rolled ultra-low carbon steel was investigated through the analyses of the chemical composition and the size of the defect itself and of the correlation between the defect and the surface deterioration of the finishing work roll in the hot strip mill. It was found that the surface defect was originated from the surface peeling of the fourth finishing work roll, which was related to the severe thermal fatigue damage due to higher hotrolling temperature. The amount of the defective strips was considerably decreased by intermediate change of the fourth work roll and by increasing the roll coolant and the lubricant. The defect was also decreased by reducing the number of the ultra-low carbon steel coils in one rolling campaign. Complete prevention was achieved by changing the roll material from nickel-grain cast iron to high-chromium cast iron (Received December 8, 1997) |