Directionality of mechanical properties in hot-rolled steel plates

Abstract

Details are presented of directionality in the mechanical properties in hot-rolled steel plates made via BOS steelmaking and conventional ingot casting. The main causes and degree of directionality are outlined. Some difficulties caused by directionality are illustrated. First, the problems in achieving the transverse impact requirements in a number of 9% nickel steel specifications are presented. The directionality of impact properties, the steel specifications, the heat-treatment response, the uses, and the demand for this steel are considered. The importance of elongated non-metallic inclusions and the effect of increased cross rolling on the transverse impact properties are confirmed. Secondly, work carried out to give a limited improvement in through-thickness ductility in ordinary structural steel plate is described. Several steelmaking, rolling, and compositional variables were examined. A number of significant relationships have been established between the through-thickness ductility and the production conditions.