Numerical simulation and optimization of polygonal roll-pass system in stretch reducing process

FANG Yi; ZHANG Yu; YIN Yuande

doi:10.3969/j.issn.1001-196X.2025.05.011

Abstract：Aiming at the appearance of roll trace and external folding defects in the stretch reducing unit of a certain steel pipe company due to over-filling,the stretch reducing process of 18 stands of typical specification Φ73 mm×5 mm thin-walled tubes of T22 steel was simulated using the FE analysis software Simufact based on the existing equipment,and the metal flow,temperature distribution,stress/strain,wall thickness distribution and groove filling of the rolled tube were analyzed.Simulation results show that during the stretch reducing process of the thin-walled tube,the metal in the deformation zone of the working stand from R8 to R14 comes into contact with the roller ring of the roll,resulting in over-filling of the groove.By optimizing the width of the groove and the local curvature,a polygonal groove structure was designed,which solved the over-filling problem and ensured the accuracy of the wall thickness,and verified its universality for the stretch reducing process of the Φ73 mm×13 mm thick-walled tube.The results show that during the stretch reducing process of the thin-walled tubes using the groove optimization scheme,no over-filling of the groove occurs.The longitudinal average wall thickness non-uniformity has decreased by 0.75%compared to the original scheme.Thetransversewall thickness non-uniformity of the thick-walled tube is 2.83%,which is 0.47 percentage points lower than that of the original scheme,while the P value of the inner hexagonal degree only increases by 4.85%,which demonstrates that the optimization scheme effectively reduces the defects of roll trace and external folding of steel pipes and has good engineering application value.