板坯连铸提高拉速工艺研究与实践

对首钢二炼钢板坯铸机提高拉速的工艺进行了研究。为适应1．2～1．3m／min拉速条件下稳定正常的生产，对结晶器冷却水量、浸入式水口参数、二冷比水量、振动参数、保护渣性能指标进行了调整，最高拉速达到了1．4m／min。研究了拉速变化对结晶器热流密度的影响、提高拉速后对结晶器铜板温度的影响、矫直区铸坯表面温度变化、保护渣耗量的变化等。通过采取以上措施，与0．8m／min拉速情况对比，铸坯表面纵裂发生率维持在同一水平，含铌的微合金钢种一检合格率显著上升，铸坯内部质量维持在同一水平。板坯双流铸机改为单流铸机后，由于拉速的提高，板坯月产量达到了9．5万t，达到了双流铸机的产量水平。

Research and Practice on High-speed Wide Slab Continuous Casting

The high-speed casting practice on slab caster in Shougang No. 2 steelmaking plant was studied. In order to reach a casting speed of 1.2-1.3 m/rain, the mould cooling water density, the parameters of submerged entry nozzle, secondary cooling water density, oscillation parameters, the physical and chemical properties of mould powder,were adjusted and the maximum casting speed of 1.4 m/rain was reached. The relationship between casting speed and local heat flux in mould, the copper plate temperature at different casting speed, the slab corner temperature in bending segment at different casting speed, the consumption of mould powder were analyzed. After that, the product quality and productivity were improved. Comparing with the product cast at 0.8 m/min, the product qualification rate of steel with Nb increased dramatically. With the increased casting speed, the productivity of this onestrand caster is ninety-five thousand tons per month the same as of the two-strand caster from which the one-strand caster was rebuilt.