高强度海工钢特厚板差温轧制工艺

Gradient temperature rolling process of high strength marine steel extra thick plate

针对特厚板轧制后组织和变形分布不均匀问题,研究了差温轧制工艺对高强度海工钢特厚板变形和组织的影响规律。基于修正后的Gleeble热压缩试验数据构建了海工钢的材料模型,并对有限元软件进行了二次开发。采用冷却和轧制耦合的方法对差温轧制过程进行了模拟,研究了压下率和换热系数对特厚板厚度方向变形行为与动态再结晶晶粒尺寸的影响,并与传统等温轧制进行了对比。结果表明,随着换热系数的增大,钢板厚度方向的温度梯度逐渐增大,表层的等效应变逐渐减小,心部的等效应变逐渐增大,厚度方向的变形更加均匀。压下率越大,差温轧制对促进心部变形的效果越显著。差温轧制能够显著细化动态再结晶晶粒尺寸,换热系数越大,钢板整体的平均动态再结晶晶粒尺寸越小。

In view of the uneven distribution of microstructure and deformation of extra thick plate after rolling,the effect laws of gradient temperature rolling process on the deformation and microstructure of high strength marine steel extra thick plate were studied.Based on the modified Gleeble thermal compression test data,the material model of marine steel was constructed,and the finite element software was redeveloped.The gradient temperature rolling process was simulated by the coupling method of cooling and rolling.The effects of reduction rate and heat transfer coefficient on the deformation behavior and dynamic recrystallization grain size in thickness direction of extra thick plate were studied,and compared with the traditional isothermal rolling.The results show that with the increase of heat transfer coefficient,the temperature gradient in the thickness direction of steel plate gradually increases,the equivalent strain of the surface layer gradually decreases,the equivalent strain of the center gradually increases,and the deformation in the thickness direction is more uniform.The larger the reduction rate is,the more significant the effect of gradient temperature rolling on promoting the deformation of the center is.Gradient temperature rolling can significantly refine the dynamic recrystallization grain size.The larger the heat transfer coefficient is,the smaller the average dynamic recrystallization grain size of the whole steel plate is.