连铸板坯表面纵裂纹原因分析及控制措施

Cause analysis and control measures of longitudinal cracks on the surface of continuous casting slabs

通过对济钢第三炼钢厂连铸工艺环节的分析,认为引起板坯纵裂纹的主要原因是钢水成分和质量、浸入式水口的尺寸及浸入深度、结晶器冷却强度、保护渣性能及其吸收夹杂物后成分和性能变化等。通过采取措施使板坯的表面纵裂纹得到有效的控制,纵裂纹发生率由1.86%控制到0.65%左右。

By analysis of each CC processing step in No. 3 Steel-making Plant of Jinal Iron Steel Co. ,Ltd, it＇s concluded that the primary causes to the formation of the surface longitudinal cracks of the CC slab are determined to be the chemical compositions and quality of the liquid steel, the dimension and depth of the submerged tube, the cooling intensity of the mold, the performance of the mold flux and the changes of the chemical compositions and performance of the flux after its absorption of the inclusions and etc. Since implementation of certain appropriate technical measures to check the surface longitudinal cracks the formation rate of the cracks has been cut down from the original 1.86% to 0. 65%.