Shao Jian

Research and Application of Work Roll Contour Technology on Thin Gauge Stainless Steel in Hot Rolling

Shape control is the key technology for thin gauge stainless steel in hot rolling. Because of high rolling force, work roll can suffer from serious uneven wears, edge drop of strip temperature and so on. And in turn these imperfections lead to defects in thin gauge stainless steel production, such as big crown value, quarter wave, edge profile anomalies, poor rolling stability. In order to improve shape the control ability, one will have to eliminate the quarter wave, make roll wear uniform, increase rolling stability in the thin gauge stainless steel production, use high performance variable crown technology in upstream stands, use mixed variable crown technology in last stand, and use conventional work roll with variable shifting stroke strategy in other downstream stands. The above technologies have been successfully applied in several stainless steel productions, which have completely independent intellectual property rights, and the crown control precision of thin gauge stainless is 98.1%, flatness control precision is 97.5%, also a 1260 mm × 1.6 mm ultra-thin gauge stainless steel was successfully developed.

Roll Deformation Model of Four High Hot Rolling Mills Based on Improved Influence Function Method

Roll deformation is an important part of profile and flatness control system. Computation speed and accuracy of roll deformation model is a research hotspot, which provides a precondition for online application. This paper puts for- ward a new roll deformation model of four high hot rolling mills based on improved influence function method. In the new model, the roll bending calculation uses elastic beam method based on the mechanics of materials theory, which avoids complex algorithms for solving influence coefficient matrix. The relationship between roll flattening and rolling force is fitted by quartic polynomial, which avoids complex iteration algorithm because of their nonlinear relationship. In iteration process of deformation coordination equation, element flattening difference and center flattening correction mod- el are developed, which avoids calculation efficiency problem due to double iterative in the influence function method. By comparison with the finite element method and influence function method, the new model has faster calculation speed and higher precision, which satisfies the online application requirement, and provides the guarantee for high precision quality control.

Multi-objective and satisfactory optimization design of backup roll chamfer parameters for hot strip mills

In the hot rolling production, in order to avoid or delay the invalidation of backup roll end, a chamfer transition is often designed at the end of backup roll. But the selection of specific parameters of backup roll chamfer for different width hot strip mills, which do not attract too much attention. In this paper, based on the comprehensive consideration of various factors including contact pressure between work roll and backup roll, and shape control capabilities, the multi-objective and satisfactory optimization model of backup roll chamfer parameters has been established, and optimized computing has been done with simulated annealing genetic algorithm for specific examples, This paper proposes a set of method on the design of backup roll chamfer for different width rolling mills, and provides a theoretical guidance for the practical application.