Application of computer modeling for the evaluation of performance of a new method of cross-screw rolling

In the process of manufacturing seamless pipes and solid round-shaped rolled products, it is customary to apply the procedure of cross-screw rolling in which the process of deformation is carried out under the action of intrafocal axial compression. This process exerts a significant influence on shaping of the workpiece due to the presence of significant transverse deformation. We propose a new method of cross-screw rolling with intrafocal axial stretching. This method is based on the creation of conditions under which the workpiece is deformed with axial tension. For this purpose, we propose to calibrate working rolls with a comb in front of the gripping zone. The assessment of the stress-strain state of the process of screw rolling carried out under the influence of intrafocal axial compression and tension was performed with the help of computer simulation by using the QForm 3D program. The assessment of the adequacy of computer modeling was carried out by comparing the deformation and energy parameters of the experimental rolling in a 14–40 mini-mill and its computer model. The discrepancy between the experimentally obtained values of the deformation and energy parameters and the values given by a computer model does not exceed 15%, which is acceptable and adequate for the analyzed conditions. At the same time, the difference between the values of ovality factor does not exceed 3%, which reflects a positive influence of the experimental calibration on reducing the transverse strains in the workpiece.

Thus, the implementation of the process of cross-screw rolling with intrafocal axial tension is a promising technological solution for decreasing transverse strains and increasing the efficiency of the process of rolling of metallic workpieces with circular cross-section.