Research on variable crown work roll curve design for W-shaped profile control of strips

The control of strip profiles has been one of the challenges faced by plate and strip enterprises. Wide rolling mill lines are usually plagued with W-shaped profile defects, which severely hamper the improvement of strip product quality and production stability in enterprises. Due to the lack of efficient control methods for the distribution characteristics of W-shaped profiles, the conventional continuous variable crown (CVC) or CVC plus rolling curve cannot meet the current quality standards required for strip rolling. Therefore, a novel roll contour curve was created by utilising the curve subsection superposition method to achieve precise control of the W-shaped profile. The roll correction areas were constructed along the width direction of strips based on the contour curve of a CVC roll. Additionally, the roll curve was modified by using the segmented cosine functions, to lower the reduction at the quarter of the strip width and increase the reduction at the strip edge. The application findings demonstrate that the proposed novel roll contour, which also has a capacity for the quartic crown adjustment, can effectively address the W-shaped profile issue of strips in the production of wide rolling mills, without compromising the quadratic crown adjustment characteristics of the original roll contour.