Abstract
The present work is devoted to the study of deformability of high-strength and hard-to-deform materials. Today the most promising technology for their forming is a rolling in a ductile shell also known as sandwich rolling. Despite the fact that the use of such technological shells allows to effectively reduce the rolling forces and soften the stress state, they have not got wide application in manufacturing practice due to the accompanying disadvantages. On the basis of finite element (FE) simulation, we carried out an all-around analysis of the effect of shell material on process parameters of method: rolling force, total reduction of hard-to-deform material, deformation inhomogeneity and thickness variation of rolled sheet, stress state scheme. Analysis of computer models allowed us to highlight the main reason for the low efficiency of the known method and propose a new design of technological shells. Preliminary FE-simulation of the rolling process of hard-to-deform material in the new technological shells showed an improvement in process parameters and method efficiency. Approbation was carried out via rolling U12 high-carbon tool steel (Russian analogue of DIN C110W2 tool steel), which has low plasticity and high hardness, on the rolling mill Duo 250 under laboratory conditions. Evaluation according to technological criteria – reducing the rolling force, increase of the total reduction and the deformation uniformity of hard-to-deform material, improvement of its deformability – showed the prospects of using proposed technological shells in manufacturing practice.
Technological Shells in the Processes of Rolling Thin Sheets From Hard-To-Deform Materials