差温轧制连铸钢坯芯部孔洞压合过程数值模拟

Numerical Simulation of Void Closure in the Core of Continuous Casting Steel During Temperature Gradient Rolling Process

基于“温度-形变”耦合控制的高渗透差温轧制技术,通过DEFORM有限元软件研究了差温轧制过程中轧制前强水冷与轧制压下率对铸坯芯部缩孔压合的影响规律.研究结果表明,温度梯度是金属变形流动的主要影响因素之一,增加水冷时间等工艺条件可以提高铸坯芯表温差,获得较大温度梯度,有效提升轧制变形渗透性;在提高铸坯温度梯度的条件下,通过增加单道次轧制压下率可以进一步提高铸坯芯部金属流动性,促进孔洞压合,改善铸坯内部质量.

Based on the high permeability temperature gradient rolling technology by temperature-deformation coupling control,the effects of the intensive water cooling before rolling and rolling reduction ratio on void closure in the core of the bloom were studied by numerical simulation using DEFORM software.The results show that temperature gradient greatly affects the deformation flow of the bloom.Increasing the water-cooling time increases the temperature difference between the core and the surface of the continuous casting steel,which leads to a larger temperature gradient,so that the deformation permeability of rolling can be enhanced effectively.Moreover,an increasing reduction ratio of the single-pass rolling combined with the temperature gradient can further increase the deformation flow in the core of the bloom,which promotes the void closure,so that the quality of the continuous casting steel can be greatly improved.