Analysis and Control of the Slab Hot Ductility Behaviors Based on Nozzle Arrangement during Continuous Casting

The spray cooling efficiency is greatly influenced by the nozzle arrangement, which correlates with the water flux distribution on the blank surface in continuous casting process. Herein, the temperature-hot ductility quantitative relation (THDR) model is established with the high-temperature tensile test data, and the effects of nozzle arrangement on the distribution of water flux, temperature, and hot ductility are investigated. The results show that the spray distance influences the water flux in the whole spraying coverage area, while the nozzle spacing only impacts the water flux in the spray overlapping area. The distribution uniformity of the slab surface temperature gradually increases with increasing the spray distance, meanwhile, it increases first and then decreases as the nozzle spacing increases. Moreover, the hot ductility distribution is calculated using the THDR model, and the results reveal a different variation. Specifically, the sizes of the high hot ductility areas in the slab surface center and edge decrease with the spray distance increases, and the uniformity of the hot ductility distribution decreases with the increase of nozzle spacing. Combining the above research, a new strategy/approach for nozzle arrangement is proposed, which can improve the crack resistance of the slab surface. The nozzle arrangement directly influences the water flux distribution, causing variations of the heat transfer efficiency in the corresponding area, which in turn influences the slab surface temperature distribution. The temperature distribution and the slab characteristics determine the hot ductility behaviors of the slab under different nozzle arrangements. Ultimately, the slab surface cracks are effectively controlled.image & COPY; 2023 WILEY-VCH GmbH