1650板坯压下过程热/力学行为及压下工艺优化

Thermo-mechanical behavior of 1 650 slab during soft reduction and optimization of soft reduction process

为了控制梅钢1 650板坯连铸包晶钢过程铸坯内裂纹发生,基于梅钢1 650板坯连铸机生产实际,建立了1 560mm×230mm断面包晶钢铸坯凝固过程三维热/力耦合有限元模型,揭示了铸坯凝固过程各冷却区内的温度场分布规律和铸坯压下过程应力与变形行为演变规律。结果表明,铸坯在结晶器及零段内冷却强度大,沿拉坯及其垂直方向的温度分布梯度大;在实施铸坯凝固末端压下过程中,铸坯宽面中心与宽向1/4处的表面变形及应力变化较为同步,且靠近铸坯内弧侧凝固前沿的塑性应变最大,铸坯应力最大值集中在角部区域;目前梅钢包晶钢连铸压下区间设置不当,易引发铸坯产生内部裂纹。

In order to control the slab internal cracking during the production of 1 650 peritectic steel slab in Meisteel, a 3D mathematical model of the solidification of the 1 560 mm× 230 mm section peritectic steel slab was estab- lished according to the practical production of 1 650 continuous casting machine in Meisteel,which revealed the distribution laws of the slab temperature in mold and second cooling zones and the evolution behaviors of stress and strain during soft reduction. The results showed that the cooling intensity and the slab temperature gradient along the direction of casting speed and vertical direction in mold and the bender segment were large. The slab surface de formation and the stress of the center and the 1/4 position of slab wide face were similar, and the maximum plastic strain occurred on the solidification front near to the inner arc of the slab during soft reduction. Moreover, the lar gest stress occurred on the shell corner. The peritectic steel slabs in Meisteel were easily suffered to the internal cracks due to the current inadequacy soft reduction process.