Study On Rolling Of Defectless Continuous Casting Slab

Continuous casting billet is superior to conventional casting and rolling in processing efficiency and energy utilization,but its complex process lead to the increase of defects.Using the characteristics of internal heat and external cooling of continuous casting billet and adopting heavy reduction rolling process will make the central shrinkage welding merge and increase the density.Therefore,in order to reduce the defects of continuous casting billet and reduce its processing cost,large reduction simulation of GCr15 bearing steel rolling end is carried out,and the effect of different roll shapes on central shrinkage is discussed.Using the multi-step module(MO preprocessor)of Deform V11 software,the temperature field of continuous casting slab model was simulated firstly,and the temperature field was similar to the actual situation.Then the rolling process was simulated by using the thermal-mechanical model with temperature field,and the shrinkage defects were simulated by using the spherical voids in the center of the model.Then the rolling simulation of the same roll with different reduction was carried out.Finally,the rolling simulation of the roll with different diameter difference and the rolling simulation of the roll with different flange width were carried out.After the simulation,the evolution of defects was analyzed and the advantages and disadvantages of different roll profiles were summarized.The following conclusions are drawn: at the end of solidification of GCr15 bearing steel billet,when the reduction is 40 mm,the central shrinkage height of 4.5 mm was compressed.The strain caused by the convex roll was lower than flat roll,and the tension effect on the direction of the defect rolling was smaller.For 410 mm ×530 mm billet,the wider the width of the convex was the better.But the effect of the convex was similar to that of the flat roll.Therefore,the convex should not be too large or too small to cover the center of the billet as much as possible and reduce the rolling force on both sides was the most suitable choice for the cam roll.Figure 54;Table 4;Reference 74.