微合金化钢连铸坯边角部无缺陷生产技术开发

Development of production technology of micro-alloyed steel continuous casting billet without corner defects

以邯宝炼钢厂板坯连铸机为依托,以实际生产的典型铌、钒、钛微合金化钢为研究对象,系统研究了板坯表面裂纹缺陷形成机理,确定了倒角结晶器窄边铜板的最佳角度和最佳倒角长度;设计并开发了具有组合式冷却水道的倒角结晶器窄面铜板,适用于带倒角连铸坯的新型支撑足辊系统;结晶器窄侧锥度的设计及应用管理,有效支撑了带倒角连铸坯的窄边,解决了角纵裂及角纵裂漏钢的难题,提高了结晶器窄边铜板的使用寿命,同时为连铸的高拉速提供了保证。项目突破了倒角结晶器技术工业化应用的技术瓶颈,从根本上解决了微合金化钢连铸板坯角部横裂纹问题,成功实现了大规模工业化稳定生产。

Based on slab continuous casting machine in Handbao Steelmaking Plant,typical niobium,vanadium and titanium microalloyed steel produced in practice are studied,and the formation mechanism of surface crack defects on the slab was systematically studied.The best chamfer angle and chamfer length of chamfered mould’s narrow side copper plate were determined.Chamfered narrow side copper plate with combined cooling structure,suitable multisection support roll applies for chamfered slab were designed and developed.The design and application management of taper on narrow side of mould can effectively support the narrow side of continuous casting slab chamfering slab side area,solve the problem of corner longitudinal crack and corner longitudinal crack steel leakage,improve the service life of narrow side copper plate of mould,and guarantee the high drawing speed of continuous casting.The project broke through the technical bottleneck of industrial application of chamfering mould technology,fundamentally solved the problem of transverse crack at the corner of continuous casting slab of micro-alloyed steel slab,and successfully achieved large-scale industrial and stable production.