Study Of Relationship Between Plate Mill Additional Bending Or Stiffness Androlling Force Variation

Baosteel plate mill is one of the world’s most advanced plate mill at present. Currently, the plate mill appear on both sides of the finishing mill rolling force variation problems, which leads export of steel occurring camber phenomenon, seriously affect the quality of the plate and the life of the mill equipment, which will also bring very large economic losses. So the impact study of the plate mill rolling force variation is very important for the production of slab steel. Considering the main transmission system and the stand stiffness difference will directly affect the symmetry of mill operate and drive sides, so this article carried out lot of theoretical and experimental research from angle of the main transmission system and the stand stiffness aiming at Baosteel 5000 mm plate mill rolling force variation on both sides.Based on the characteristics of plate mill, according to the condition of the mechanical deformation, kinematics, etc. using the influence coefficient method to calculate the force and deformation of roll system, considering the impact of the rolls deflection by additional bending and rolling stand stiffness, the paper also established a rolling force variation offline calculation model.There is an angle between the input shaft, universal joint shaft and the output shaft in the plate mill main transmission system, the input shaft generate an additional bending during transferring torque. The paper considered the impact of rolling force variation by the main transmission system and established the mechanical model of the main drive system, researching the impact of rolls deformation, rolling deformation and rolling force variation by additional bending.The paper researched the effects of rolling force variation by the stand stiffness, especially analyzed the effects of rolling force variation by oxide scale. This paper also measured the stiffness of the oxide scale by using equal pressure pressed against method,the mill stand stiffness model was established under the influence of oxide scale and analyzed the effects of stand stiffness, rolls rigid displacement and rolling force variation by oxide scale.According to the actual situation, the rolling force variation affected by the self-designed program simulation and finite element simulation of one side push different sizes and different thicknesses of oxide scale was received, and two calculation methods calculate similar results. Analyzing of the degree of influence of residual oxide scale, provide a reference to remove the oxide scale regularly.The research results laid the theoretical research foundation for the plate mill rolling force variation problem and provided a good solution to solve the rolling force variation problem, and also played an important role for improving the stability of plate rolling.