Lubrication characteristics of physical vapor deposition Tin-coated roll for high productivity in cold rolling of low-carbon steel sheet

The prevention of friction pickup, which often occurs under the condition o f high rolling reduction and/or high rolling speed, is required to improve productivity in the cold sheet rolling of low-carbon steel. Therefore, the lubrication characteristics of a TiN-coated steel roll treated by the physi cal vapor deposition (PVD) process are evaluated quantitatively and compare d with those of a conventional steel roll. Coefficients of friction for the reduction in thickness and the limit of the reduction of friction pickup a re measured using a sliding-rolling simulation testing machine. The experim ental results show that the limit of the reduction of the TiN-coated roll i s much higher than that of the conventional roll. Moreover, the maximum rol ling speed of the TiN-coated roll used in an actual mill is calculated. The results show that the maximum rolling speed of the TiN-coated roll will be two times faster than that of the conventional roll. (C) 2001 Elsevier Sci ence B.V. All rights reserved.