关键词: 非稳态浇注, 压下区间, 凝固传热, 连铸板坯

Abstract:

To reduce center segregation and center porosity and improve internal quality of casting slabs based on adopting dynamic soft reduction，according to the measured data of the slab surface temperature during the actual production process of transient casting，a solidification heat transfer model was corrected. The variation rule of the effect of casting speed，superheat degree，and specific water flow on reduction position was analysed. The results show that for every 0.1m/min increases in casting speed，the reduction length of AH36 and Q235B increases 0.15m and 0.21m respectively，and for every 10℃ increases in superheat degree，the reduction length of AH36 and Q235B increases 0.01m and 0.015m respectively，and for every 0.1L/kg increases in specific water flow，the reduction length of AH36 and Q235B increases 0.04m and 0.06m respectively. After the solidification heat transfer model was applied to production，the center segregation reduces to 1.0B~0.5C，and the center porosity less than level 1.5 increases from 35.25% to 85.16%，and the slabs internal quality is improved obviously.

Key words: transient casting, reduction zone, solidification heat transfer, continuous casting slab