Experimental Study of Roll Flattening in Cold Rolling Process

抄録

Precise control of the sheet thickness in cold rolling process is becoming more and more important. Sheet thickness after cold rolling, depends on the initial thickness, the initial roll gap as well as the elastic deformation of the rolling mill including rolls. As production amount of high-strength materials increases, the elastic deformation of rolls becomes larger and more important. In cold rolling of high-strength steel sheets, it is reported that the rolls show non-circular deformation and the rolling load predicted by Hitchcock’s equation does not agree with experiments. In this study, stainless steel sheets were cold-rolled and the profiles of the partly rolled specimen were measured by a laser profilometer. Meanwhile, data processing method to reveal the sheet profiles in the roll bite is developed. Flattened radius R_P calculated from the measured profile is smaller than the radius R_H estimated by Hitchcock’s equation. In addition, the contact length L_M estimated with consideration of elastic deformation of the sheet is in good agreement with L_P measured by a laser profilometer under three lubrication conditions.