Mathematical model for calculating the parameters of straightening section profiles on a roller straightening machine

Abstract

The analysis of the traditional theories of straightening section and shaped steel on a roller straightening machine (RSM) according to the methods of Korolev and Tselikov - Smirnov, using the linear law of change in the coefficient of penetration of plastic deformation along the height of the rolled product. It is shown that when straightening a steel angle 200 - 200 - 24 mm (σs = 440 MPa) on a nine-roller straightening machine (SM), the greatest discrepancy in the calculation of bending moments and straightening forces according to the Korolev and Tselikov - Smirnov methods is equal to 25 % and is observed on roller No. 4. A refined mathematical model is proposed to calculate the parameters of straightening of long products on the RSM. It provides a more accurate definition of the boundary between the elastic and plastic zones as a result of taking into account the bending hardening. On the basis of the developed model, an algorithm to calculate the straightening parameters of long products for an eight-roller SM of the universal rolling mill 650 of the Nizhniy Tagil Metallurgical Plant (NTMK) has been compiled. Comparative results of the calculated and experimental straightening forces for hardened rails 65R on the eight-roller SM of the plant are presented, confirming the adequacy of the developed model with an error of 20 %. The results of the study can be applied in calculating the parameters of straightening profiled sections, as well as in the modernization and design of RSM.