Study of the minimum strip thickness for non-symmetric rolling

The asymmetric rolling process with different circumferential speeds of rotation of the work rolls expands the technological capabilities of cold rolling mills. By reducing the contact normal stresses in the deformation zone, the elastic deformations of the rolls are reduced, which makes it possible to use asymmetric rolling processes to obtain the thinnest strips and foil. However, the minimum thickness for these processes is limited by the contact of the rolls at the edges of the drums, which is not permissible, because this circumstance leads to a sharp increase in the rolling force, an increase in the temperature of the rolls at the edges of the barrels, additional thermal stresses and breakdown of the rolls. The purpose of the study on the minimum strip thickness in asymmetric rolling is to establish the features of its achievement and to evaluate the calculated and experimental data. In this case, the minimum strip thickness in a pass during asymmetric rolling is understood to be such a thickness at which the work rolls, due to their radial deformation and bending, come into contact at the edges of the drums. It has been established that the minimum thickness during asymmetric rolling, in particular during rolling-drawing, is 2-3 times less than in the conventional rolling process. In this case, the less the strip stretching in the passage, the smaller the strip thickness can be obtained. A comparison of the experimental and calculated values of the minimum strip thickness during rolling-drawing was carried out, which confirmed the possibility of using engineering techniques to determine the minimum strip thickness in the passage from the condition of the rolls contact at the edges of the barrels.