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.

Aiming at solving the problem that results from flow instability two-component materials, uneven density and thus affects the product quality in constant pressure casting stage. Based for theory of polymer materials and hydrodynamic, establishing mathematic model of filling stage and proposing a uniform filling strategy through analysis of geometric characteristics of different mold, set pressure regulation curve in order to ensure uniform filling and stable flow for two-component materials in pressure casting stage. The experiment shows that the proposed method can actually ensure uniform filling, but also eliminate the product defects such as insufficient injection and burr, thus presenting a feasible solution to the problem of flow instability two-component materials and uneven density.