Current Research Trends in Three-High Screw Rolling and Piercing of Steel Billets

A review has been conducted to determine current research directions in three-high rolling and piercing of steel billets. The billets are made of carbon, low-, medium-, and high-alloy steels. Investigations related to billet fracture processes are important. Fracture is found to be both ring-shaped and axial. Results on qualitative and quantitative estimation of a microstructure and the influence of three-high screw rolling on mechanical properties are presented. A submicron structural state has been achieved in a number of works; an increase in yield strength and tensile strength and a decrease in relative elongation have been detected in all studies. Some works detected the influence of three-high screw rolling on impact toughness. Compared to rolling, piercing has been studied much less frequently. The change in the grain size across the wall thickness and the changes in the hardness and the mechanical properties are investigated.