非平衡凝固对铸坯末端两相区长度的影响

通过分析代表性的正六棱凝固结构的微观偏析模型,结合实际多组元钢种,建立了钢的凝固过程溶质微观偏析有限差分模型。模型计算得到的非平衡固相线与Jernkontoret公布的有关实验数据吻合。20钢、45钢和U71Mn钢的280 mm×380 mm连铸坯传热计算模型的应用表明,采用非平衡固相线计算的铸坯中心两相区长度比采用平衡固相线计算的长,并且随钢中碳含量的增加而增大;修订的凝固参数与建立的模型能更准确地反映铸坯的凝固进程。

Effect of Non-Equilibrium Solidification on Length of Liquid-Solid Region at Solidifying Front of Concasting Bloom

The model of finite differential method for solutes micro-segregation during solidification of steel has been established by analysis on representative regular hexagonal dendrite structure micro-segregation model combined with applied steel grades. Non-equilibrium solidus lines calculated by established model coincide with the related experimental data published by Jemkontoret. The application of heat transfer calculating model for 280 mm x380 mm casting bloom of 0. 20C steel, 0. 45C steel and U71Mn steel show that the length of liquid-solid region at center of bloom calculated by non-equilibrium solidus is longer than that calculated by equilibrium solidus and it increases with increasing carbon content in steel ； and the revised solidification parameters and established model are more precise to reflect the solidification process.