Hot Rolled Slab Unsteady Rolling Roughing Stage Mechanical Behavior Research And Quality Control

With the development and optimization of strip thickness control systemand shape control system, precision of strip on steady-state rolling has beengreatly improved. However, on unsteady edge and horizontal rolling the headpart and tail part of slab, which have uniform deformation and width change,have to be trimmed before the finishing stands and it will lead to increasechip-off and decrease incoming ratio. Width control mainly depends on verticalroll in rough rolling, however, width loss and fish-tail at the head and tail endswill appear. In order to decrease width loss, SSC (Short Stroke Control) wasapplied in edger rolling. The background of the thesis is some1500hot strip mill,3D explicit dynamic elastic-plastic finite element model, which was based onelastic-plastic finite method. On unsteady rolling stage, deformation regularityand control mechanics of cross-section deformation, width loss, head and tailshape was analyzed. And the process of SSC was simulated, SSC processspecification curve was obtained and can be used in practical production.The main research contents of this thesis are described as follows:(1) Elastic-plastic model of edger rolling and edger-horizontal rolling weresimulated by large commercial finite element software ABAQUS/Explicit, takeninto material nonlinearity and geometric nonlinearity of rolling.(2) When edger rolling, dog-bone shape section, width loss at head and tailends, fish-tail deformation for different width reductions, entry slab thickness,slab width were analyzed.(3) As edger-horizontal rolling, dog-bone shape section, width loss at headand tail ends, fish-tail deformation for different width reductions, thicknessreductions, entry slab thickness, entry slab width was analyzed.(4) Short Stroke Control process, toward different rolling conditions, wassimulated by dynamically changing edger roll gap. Regression curve of SSC wasobtained and can be helpful for practical production.