连铸420mm特厚板坯质量控制

Quality control for continuous casting 420mm Extra-thick slab

连铸特厚板坯易发生角裂、中心偏析倾和内部夹杂物影响探伤合格率等问题，采用理论分析、仿真计算、实验室实验和生产现场试验的方法，研发了防止特厚板坯角部裂纹技术、特厚板坯均质化控制技术、内部夹杂物控制技术。实施结果表明，生产特厚板坯质量良好，没有角裂，中心偏析水平主要集中在C0．5～C1．5范围内，特厚板探伤合格率平均96％。本研究成果对生产特厚板坯时控制质量具有重要意义。

For the problems of Corner crack, center segregation and inclusions effect ultrasonic detection qualified rate in continuous casting extra-thick slab. The technology of prevent corner cracking of the extra thick slab, extra thick slab homogenization control technology and the control of internal inclusions have been studied by theoretical analysis, computational fluid dynamics, lad experiments and field test. The results show that extra thick slab products are high quality without corner cracking and the central segregation level mainly concentrated in the range of C0.5-C1.5. The average inspection qualified rate of the extra thick slab is 96%. The results of this study have important significance to the quality control of the production of extra thick slab.