Method of hot-forming metals prone to crack during rolling

Abstract

A method of continuously casting a molten ferrous alloy in a casting means to obtain a solidifed cast bar at a hot-forming temperature, passing the cast bar at a hot-forming temperature from the casting means to a hot forming means, and hot forming the cast bar into a wrought product by a two-stage reduction of its cross-sectional area while it is still at a hot-forming temperature, including, in the first stage, the step of forming a substantially uniform fine grained, equiaxed or cell structure in the outer surface layers of the cast bar by a selected small amount of deformation of the cast bar in its as-cast condition prior to the second stage in which substantial reduction of its cross-sectional area forms the wrought product. The substantially uniform subgrain structure formed on the cast bar during the first stage of deformation produces a bar that has increased ductility compared to bar produced by the prior art processes and permits substantial reduction of the cross-sectional area of the cast bar during the second stage of deformation without the cast bar cracking, even when the cat bar has a relatively high precentage of alloying elements present.