Study On Axial Force And Axial Torque In Radial-Axial Ring Rolling Process

In radial-axial rolling process of large ring, the structure of ring rolling machine, rolling technology and the parameters of ring all have an important influence on rolling ring smoothly. In the process of designing ring rolling machine, force and torque are related to determine the technical parameters of the host, design reasonable structure, analyze the strength and stiffness of the mechanism. Metal flow can be analyzed and the limit deformation can be controlled and the stability of rolling process also can be improved by analyzing the relationship between axial force and axial torque and the process parameters. The calculation formulas of axial force and axial torque are established and the influence of process parameters on the axial force and axial torque is analyzed, which are beneficial to establish a more precise rolling strategy and improve the automaticity of the equipment and the quality of ring.In this paper, the axial rolling force and axial rolling torque in radial-axial ring rolling process as the research objects are analyzed theoretically and researched experimentally. The main research contents are as following:(1) Based on the axial rolling force is equal to the contact area multiplied by the unit rolling force, the basic calculation formula of axial rolling force is established. The geometric model of contact area is established, and the calculation formula of contact area is founded by using the integral method. According to the established mechanics analysis model of the unit rolling force, the differential equation of the unit rolling force is founded and the calculation formula of the unit rolling force is established by using the principal stress method. Then the calculation formula of the average stress coefficient is established by transforming and simplifying. According to the moving volume theory, the calculation formula of axial rolling torque is established.(2) In order to verify the correctness of the calculation formula of axial rolling force, the experiment of axial rolling force is carried out. Lead is selected as the experimental material and the mechanical property of lead is tested. The yield strength of lead is measured. The experimental device is designed and the experiment of axial rolling force is carried out by using electronic universal testing machine. The error of the experimental value with the theoretical value is found in the reasonable range by analyzing experimental data and comparing the experimental value with the theoretical value of axial rolling force. The change tendency along with feed of the experimental value is consistent with the theoretical value, which illustrates the established calculation formula of axial rolling force is correct.(3) The influence of process parameters on the axial rolling force and axial rolling torque is researched. Conclusions is as following: Axial rolling force and axial rolling torque increase linearly with the increase of outside diameter of ring and decrease with the increase of inner diameter of ring. Axial force and axial torque will increase with the increase of the feed, and the effect is obvious. The importance of the impact of process parameters on axial force and axial torque is that: feed > outside diameter of ring > thickness of ring > the distance between the vertex of roller and the center of ring. Feed is the main factor.(4) The radial-axial rolling of ?3000mm ring is used as the object of study to carry out case study. The instantaneous size of ring and the mechanical parameters in real ring rolling process are used, and the actual values of axial force and axial torque are contrasted with the theoretical values, which further validate the correctness of the established calculation formulas of axial force and axial torque.In summary, the axial rolling force and axial rolling torque in radial-axial ring rolling process are analyzed theoretically in this paper. The calculation formulas of axial rolling force and axial rolling torque are established, and the influence of process parameters on axial force and axial torque is analyzed. The correctness of the established calculation formulas of axial force and axial torque is verified by using experiment and case study. The research results can provide theoretical basis to the design of ring rolling machine and the production of ring.