Influence of radial-shear drawing on the formation of gradient microstructure in steel rods

This paper presents a technology for processing carbon steel rods. The technology involves the deformation of carbon steel rods by radial-shear rolling on the RSR-10/30 mill, followed by wire drawing on a V-I/550 M drawing mill. During the simultaneous processing of a billet through crossed rolls and drawing dies, tensile stresses are generated, which result in a reduction in drawing force. These tensile stresses facilitate the formation of a more uniform profile in the drawn billet. As a result of deformation, we obtained rods with a gradient microstructure. The surface layer of the rod was characterized by a significant refinement, with an average ferrite grain size of 0.5 μm. The neutral zone exhibited a less pronounced deformation, resulting in a mildly refined structure, with an average ferrite grain size of two µm. In the central zone, the microstructure is represented by coarse grains with an average size of seven µm.