摘要 Chamfered mould has gradually become a new technology equipment to eliminate transverse corner crack. However, longitudinal corner crack ratio of chamfered slab was very high. Solidification microstructure was detected in the area where the longitudinal corner crack occurred. Effect of narrow face shape and taper distribution of mould copper plate on longitudinal corner crack was studied by industrial tests. Water velocity distribution in the narrow copper plate was studied by numerical simulation. On the premise of preventing cooling water from nuclear boiling, improvement measures of mould cooling process and water seam structure were put forward through heat transfer calculation. The results showed that local taper of the meniscus region of mould should be increased to prevent generation of longitudinal corner crack. Chamfering slope length of narrow copper plate should be controlled within 55 mm, and chamfering angle should be controlled at about 30 ℃. Average water velocity should be more than 7.0 m/s. The flat and chamfering regions of narrow copper plate working face should be designed as double taper and funnel structure, respectively. The water seam in the chamfering region should preferentially choose the combined cooling structure with two holes and one slot. In order to prevent the extension of longitudinal corner crack, chamfered narrow face foot roller should be used.
Abstract：Chamfered mould has gradually become a new technology equipment to eliminate transverse corner crack. However, longitudinal corner crack ratio of chamfered slab was very high. Solidification microstructure was detected in the area where the longitudinal corner crack occurred. Effect of narrow face shape and taper distribution of mould copper plate on longitudinal corner crack was studied by industrial tests. Water velocity distribution in the narrow copper plate was studied by numerical simulation. On the premise of preventing cooling water from nuclear boiling, improvement measures of mould cooling process and water seam structure were put forward through heat transfer calculation. The results showed that local taper of the meniscus region of mould should be increased to prevent generation of longitudinal corner crack. Chamfering slope length of narrow copper plate should be controlled within 55 mm, and chamfering angle should be controlled at about 30 ℃. Average water velocity should be more than 7.0 m/s. The flat and chamfering regions of narrow copper plate working face should be designed as double taper and funnel structure, respectively. The water seam in the chamfering region should preferentially choose the combined cooling structure with two holes and one slot. In order to prevent the extension of longitudinal corner crack, chamfered narrow face foot roller should be used.
Hong-biao Tao,Hui Zhang,He-ping Liu, et al. Longitudinal corner crack of chamfered slab and optimization of mould[J]. Journal of Iron and Steel Research International, 2023, 30(02): 259-266.
2023, Vol. 30 
