Theoretical and Experimental Study of the Tandem Skew Rolling Process

The deformation characteristics and the roll force are of significant importance in the rolling of seamless steel tubes with a tandem skew rolling (TSR) process. In this paper, finite element methods and dual stream functions are utilized to analyze tube rolling with the TSR process. Finite element simulations reveal the deformation characteristics of the seamless steel tube during the rolling process. In addition, the kinematically admissible velocity field and the strain rate field of the deforming tube are described and derived in terms of the dual stream functions. The roll force in theoretical analysis is obtained through upper bound analysis. Experiments are carried out in a TSR testing mill on a carbon steel, to show the validity of the analysis. The curve of the roll force in the process is obtained and the variation of the roll forces is analyzed in detail. Through the comparison between the theoretical, numerical, and experimental investigations, the constructed analysis model is used to study the TSR process and establish a theoretical basis for further development of the process. Combining the piercing section with the rolling section, the billet is pierced and rolled continuously forward in a spiral way, and the seamless steel tube is obtained. The deformation characteristics of the tube is analyzed. A theoretical model is constructed for the tandem skew rolling process, and verified by experiments.