首钢板坯连铸技术进步

回顾了近十年来首钢为生产优质冷轧钢板和特厚钢板而开发的板坯连铸新技术。为了降低优质冷轧钢板表面冶金缺陷，开发了浸入式水口防堵塞技术、结晶器内钢液流动综合控制技术和中高拉速FC结晶器技术等。综合应用这些技术后，水口堵塞率降低60%以上，结晶器液面波动±3 mm比例提高至98%以上，冷轧钢板表面卷渣缺陷指数降低50%以上。为了提升特厚钢板的冶金质量，开发了特厚板坯窄面鼓肚控制技术、倒角结晶器连铸技术、半干法连铸技术和二冷间歇式喷淋等技术，400 mm厚板坯窄面鼓肚量降低至5 mm以下，含铌微合金化钢板坯表面裂纹发生率大大降低。开发了特厚板坯连铸轻压下技术，中心偏析C类1.0级及以下比例达到100%，确保了150 mm特厚钢板的心部韧性达到100 J以上。

Progresses of continuous casting technology development at Shougang Group

Progress of developed continuous casting technology to produce high quality cold rolled sheets and heavy plates in Shougang during the last ten years was reviewed. In order to minimize the metallurgical surface defects of high quality cold rolled sheets, several technologies were developed including the clogging prevention of submerged entry nozzle, the integrated control of flow pattern in CC mold, the optimization of FC mold under medium high speed CC. After the comprehensive application of these technologies, the ratio of SEN clogging was reduced by more than 60%. The percentage of fluctuation of mold level within ±3 mm was higher than 98%. The index of surface defects caused by entrapped mold powder was reduced by more than 50%. Aiming to improve the metallurgical quality of the extra thick steel plate, some technologies including the control of narrow bulging, chamfered mold CC technology, and semi dry and batch type secondary cooling pattern were developed. The bulging content of narrow face of the slab caster with a thickness of 400 mm slab was reduced to 5 mm. The incidence of surface cracks of Nb contained slabs was significantly reduced. Soft reduction technology for ultra thick slab continuous casting was developed, and the center line segregation was totally controlled below grade 1.0 of C type segregation, which ensured the core toughness of 150 mm ultra thick plate over 100 J.