Effect of stress-strain state during helical rolling on metal and alloy structure and ductility

Abstract

A working hypothesis is proposed for the mechanism of the effect of deformation regimes on granular structure and phase fineness governing an increase in ductility for silumins and low-alloy steels. In particular, an alternating nature of deformation during helical rolling (HR) provides a reduction in grain size by a factor of 5-6 compared with longitudinal rolling. For hypereutectic silumins with HR it is possible to obtain a polygonized subgranular structure, to increase α-solid solution grain and silicon crystal fineness, giving them a globular shape, and thereby provide a capacity for treatment under pressure. An important role in increasing deformation capacity of silumins is played by the new technology of melt modifying treatment and optimum temperature-rate deformation regimes. © 2013 Springer Science+Business Media New York.