非稳态浇铸连铸坯控制技术

针对连铸过程中产生的非稳态坯，通过夹杂物分析和氮氧分析，掌握各类非稳态因素对铸坯质量的定量影响。从夹杂物数量密度对夹杂物进行了分类，得到铸坯质量优先级顺序：正常坯＞尾坯＞换水口坯＞头坯。对非稳态坯进行有针对性地工艺技术攻关，采用中包充氩技术、快涨拉速技术，头坯头部全氧质量分数由研发前的7.1×10－5降低至当前的4.0×10－5；通过快降、快涨拉速协同控制技术、接痕控制技术，换水口坯大型夹杂物数量（大于50 μm）由研发前的0.8 个/cm2降至0.4 个/cm2；采用“一键式”拉速控制技术、二冷水幅切控制技术和轻压下时间控制技术，尾坯的中心疏松得到了显著改善。

Control technology of slab in unsteady continuous casting process

By inclusion analysis and nitrogen-oxygen analysis on unsteady slab generated in continuous casting process, the effect of various types of unsteady factors on slab qualityhas been quantitatively ascertained. Inclusions were classified by inclusion quantity density, and the priority order of slab qualityis obtained: normal slab>tail slab>change SEN slab>head slab. Targeted technology research on the unsteady slab has been conducted. Using argon filling technology for tundish and quickly increasing casting speed technology, thew(T[O]) in the head slab decreases from 7.1×10－5 to the current 4.0×10－5. Through quickly decreaseand quickly increase casting speed cooperative control technology and seam-control technology, the quantity of large inclusions (>50 μm) in change SEN slab has reduced from 0.8 to 0.4 per square centimeter. Using “One-Button” casting speed control technology, broad-narrow width switchcontrol technology in secondary cooling and soft reduction time control technology, the center porosity in tail slab has been significantly improved.