METHOD FOR ZERO-REGULATION IN LEVELING OF HOT ROLL FINISH ROLLING MILL

PROBLEM TO BE SOLVED: To improve the accuracy of the zero regulation in the leveling by reducing the coefficient of friction between rolls to reduce the thrust, and reducing the variance in the differential load of the zero regulation in the leveling. SOLUTION: The differential oil column in a condition where the gap between rolls is parallel during the actual rolling by a hot finish rolling mill is compared with the differential oil column during the zero regulation when the oil is applied. As indicated in the figure, variance in the differential oil column during the zero regulation is small, and matches with the differential oil column during the rolling due to regulation of the target differential load. In the zero regulation in the leveling when work rolls are re-assembled, the accuracy of the zero regulation in the leveling can be improved by applying oil to the rolls to reduce the coefficient of friction between the rolls. Though a large volume of oil is required because oil is burned during the rolling, a small amount of oil is sufficient for the zero regulation and application of oil during the zero regulation raises no problem in the oil consumption.