400mm厚连铸坯轧制时缺陷的压合模拟

Simulation of Central Defects Closing During 400mm Thickness Continuous Casting Slab Rolling

对某宽厚板厂最新投产的400mm连铸坯,以刚-粘塑性有限元模拟分析了其轧制Q345特厚钢板时的缺陷压合过程和临界压合条件。结果表明:在足够的压下率下,特厚板中心矩形裂纹能够被压合;缺陷尺寸、轧辊半径和坯料厚度对缺陷压合影响很大。缺陷尺寸和轧辊半径越大、坯料厚度越小,压合所需的临界压下率越小;在1120mm×4300mm热轧机上第1道次压合400mm铸坯中心矩形裂纹的临界压下率为15.8%,转化为几何参数为0.511。以临界变形量单道次压合裂纹效果较好。缺陷压合试验验证了有限元模拟结果。

The behavior and critical condition of defects closing during Q345 ultra-heavy plate rolling with 400 mm thickness continuous casting slab were investigated with FEM,ANSYS/LS-DYNA.The results show that the central rectangle defects in ultra-heavy plate will be closed by enough pass reduction ratio.The defects size,roll radius and slab thickness have obvious influence on critical reduction ratio.The critical reduction ratio is inversely proportional to defect size and roll radius but is proportional to slab thickness.In the hot roll mill of 1 120 mm×4 300 mm,the critical closing reduction ratio for the central rectangle defects to be closed in the first pass is 15.8%,changing into geometric parameter 0.511;meanwhile,closing central defects with critical reduction ratio has better effect.At last,the defects closing test verifies the results of simulation.