Comparative study of roll separating force and its effect on bearing life of rolling stand #3 in WRM (E) using FEA

摘要

Roughing stand #3 of Wire Rod Mill (WRM) of Tata Steel, India is studied for Roll Separating Force (RSF) for various twist condition of incoming workpiece. This stand is subjected to high bite angle (ft) and subsequent RSF. Due to design constraint, inclusion of additional stand to distribute the reduction between two stands and corresponding bite angle is not possible. Studies have been made to see the effect of RSF and axial thrust (Fx) on bearing life in order to avoid frequent failure. A finite element based 3-D model has been built up in ABAQUS 6.10 where, the roll has been modeled as an analytical rigid body and work-piece as deformable one. The computed values of RSF have been verified with the analytical formulae from literature. Several cases for incoming condition of workpiece (no twist, over/under twist by 5°, 7° and 9°) have been simulated with same boundary conditions and the results are compared. It has been found that compared to no twist condition (i.e. incoming stock is rotated by perfectly 90° about its axis to the next stand), roll separating force is less in case of under/over twist, but then there exists an additional axial thrust which has an alarming effect on bearing life for higher values of over/under twist.