Impact of two-phase region rolling on the microstructure and properties distribution in heavy gauge structural steel plate (INCROHSS).

Abstract

Heavy gauge line-pipe and structural steel plates are often rolled in the two-phase region for strength reasons. However, strength and toughness show opposite trends and the exact effect of each rolling process parameter remains unclear. A stable process window can only be achieved by a more profound understanding of the microstructure development during the intercritical rolling and its relationship with final microstructures and mechanical properties. By means of recently developed microstructure investigation techniques and modeling, the relationship between the temperature gradient, α-γ phase balance at high temperature, strain partitioning between phases and subsequent transformation was studied in detail to allow for wider process windows.