Parameters affecting lateral deformation in slabbing mills

Abstract

The nature of deformation in the roll gap during passes in which plane-strain conditions do not obtain is investigated, and it is shown that plastic flow is complex, involving material transfer from the slab edges to the roll-contact face. The factors affecting spread in the lateral directions are investigated, and it is concluded that the homologous temperature and the dimensionless group (deformed roll radius /initial slab thickness) are important factors. A new spread formula, defining spread as the natural lateral strain, is presented, and is shown to agree well with the experimental work reported. The results of over 400 rolling tests, including some tests on plant mills, are incorporated into the analysis. It is shown that a change from sticking to slipping friction modifies the deformation mode, and that the structure of the cast ingot or slab may also be an important factor influencing deformation in the roll gap.