Papers by Keyword: Seamless Tube

Abstract: During the hot piercing phase of seamless tube production, friction and contact conditions between tools and workpiece significantly influence final product quality and energy consumption. The friction effects on the production of high alloyed steels like Super Cr13 steel are critical. This study analyses the effect of different friction conditions at the workpiece-tool interface in the piercing of Super Cr13 steel bars to minimize total energy consumption in such a manufacturing process. For this purpose, a three-dimensional finite element method (FEM) is employed to simulate and analyze the piercing process. The variety of tools (plunge, rollers, and Diescher disks) and contact conditions lead to differences in the applied stress at different workpiece areas. Consequently, various friction models and friction coefficients were selected for different interfaces. The relation between strain rate, temperature, and geometry of pierced tube are discussed, and the selected friction relation with total power and energy consumption is presented. Experimental tests have been used for FEM validation and result analysis, and finally, the most effective conditions with lower total energy consumption are presented.

Abstract: Based on rolling technology of stretch reducing mill group, by using large-scale general-purpose finite element analysis software ANSYS/LS-DYNA, a 3D thermal mechanical coupled numerical calculation of stretch reducing process, stress field, strain field, temperature field and the distribution of wall thickness were obtained, as well as the distribution of asymmetrical metal deformation when pipe passing every mill. The results of numerical simulation provide a reasonable cause for uneven wall thickness distribution, guiding the design of stretch reducing process.

Abstract: The stretch reducing process is the last hot deformation process of the hot-rolled seamless steel tube’s production. Its role is to decrease the tube’s diameter under the large tension and expand the range of product specifications. But the stretch reducing process often results in wall thickness tolerance at the head and end of the tube. In order to solve the problem, a 3D elastic-plastic finite element analysis model was established to simulate the stretch reducing process of φ159 unit. Based on this, the tube’s wall thickness distribution was studied and the parameters of sharpen rolling process was put forward. Numerical simulation results indicate that with the parameters of sharpen rolling process, the length of wall thickness tolerance was shorten and the rate of finished products was proved.

Abstract: The development of new products of seamless tubes require the development of corresponding grooves in order to manufacture tubes with high precision, high efficiency at low cost. In this work, a finite element model and dynamic simulation of continuous rolling pass for seamless tubes process has been implemented under the ANSYS/LS-DYNA environment to verify the validity of the pass design. The result show the deformation characteristic of cross-section, the variation regularity of rolling force, strain and stress conform to the reality. The work is effective for developing new grooves and products for seamless tube continuous rolling.

Abstract: According to the geometrical characteristic of workpiece and groove in the stretch reducing rolling process, three-dimensional elastic-plastic finite-element analysis model was established to simulate the metal deformation, the regularities of distribution of wall thickness of transverse direction longitudinal direction were investigated. The analysis was verified by comparing finite element analysis results with on-line measurements. The length of crop ends was determined as well as product bore polygonization. The study provides the foundation for analyzing product defeat and instructing technological design.