结晶器内钢液过热度的降低可以促进柱状晶向等轴晶的转变和提高等轴晶率,从而有利于铸坯组织的均质化。基于上述原理,设计和制造了可用于降低钢液过热度的冷却水口,并在方坯连铸机上进行了工业试验,分析了低过热度技术对方坯凝固组织的影响。结果表明:采用冷却水口以后,结晶器内钢液过热度的下降幅度可达14℃,铸坯的等轴晶率提高了8%~24%,中心偏析和缩孔严重程度有所降低。 The decrease of superheat in the mold can promote the transformation of columnar grains to equiaxed grains and increase the equiaxed grain rate, which is in favor of the homogenization of slab structure. Based on the above principle, a cooling water nozzle, which can be used to reduce superheat of molten steel, was designed and manufactured. An industrial test was carried out on a billet continuous casting machine to analyze the influence of the low superheat technology on the billet solidification structure. The results show that after the cooling water nozzle is used, the degree of superheat of the molten steel in the mold can reach 14 ℃, the equiaxed grain rate of the slab increases by 8% -24%, and the center segregation and shrinkage porosity decrease.