The Prevention of Central Bursts During Rolling

Abstract

An upper bound analysis has been developed to model the flat rolling of a perfectly plastic material. A rigid body rotational velocity field was assumed for the deformation region. This field permits the possible formation of an internal void. The process conditions under which it is energetically favorable for a void to develop have been determined. It has been found that internal void formation (central burst) is more likely to occur in thick strips and sheets when small reductions are taken. Both front and back tension tend to promote the development of a central burst with the back tension reducing the safe, noncentral burst domain to a greater degree. Criteria curves for the central burst domain and the safe domain are presented for a wide range of process variables.