安钢板坯凝固规律的研究与应用

Study on solidification rule for slab in Anyang Steel and its application

介绍了利用事故坯壳法、缺陷坯特征法及射钉试验法3种板坯铸机综合凝固系数的测定评价方法,旨在考察不同钢种综合凝固系数选取的科学性及合理性,确定不同钢种的凝固末端,为辊缝收缩设计优化、细化完善冷却制度提供科学依据;通过测定、计算与分析,分别得到的综合凝固系数为0.024 0、0.022 1、0.022 4～0.025 5 m.min-0.5,其中采用事故坯壳测定法描绘出坯壳厚度与凝固时间的对应关系,得到凝固方程与理论凝固方程基本吻合;并通过优化辊缝、细化冷却制度,使铸坯低倍评级达到了C类中心偏析1.0级、中心疏松0.5级、中间裂纹0.5级。

The present article introduces three methods for measurement of integration solidification factor of slab caster , i.e. measurement of the broken slab shell, the char- acteristics of defect slab and the nail-shooting test aiming at checking the rationality of the integration solidification factors selected for various steel grades and fixing on the fi- nal solidification points for those steel grades in order to provide the necessary scientific data for optimization of the design on the roll gap shrinkage and improvement in the cooling system. By measurement, calculation and analysis the integration solidification factors 0. 024 0,0. 022 l and 0. 022 4~0. 025 5 m＇min-~＇s are obtained respectively and relationship between the shell thickness and the solidification time is depicted by way of the accidental shell measurement method and the practical solidification equation basical- ly agrees with the theoretical equation. By optimizing the roll gap and by modifying the cooling system the rating of macrostructure of the slab namely 1.0 grade for center seg- regation, 0. 5 grade for center porosity and 0. 5 grade for middle crack at class C are re- alized.