超低碳钢150t转炉冶炼过程超低硫的控制和工艺实践

Control of Ultra-Low Sulphur during 150 t BOF Ultra-Low Carbon Steel Steelmaking and Process Practice

结合转炉超低硫钢研发试验及生产实际,分析了转炉原材料中硫含量分布,得出铁水及带渣量、废钢、石灰占转炉入炉原料总硫质量分数的70%以上;研究了150 t顶底复吹转炉碳氧积对终渣（FeO）的影响,吹炼时间（0～15 min）、炉渣综合碱度R（2～4）和（FeO）（15%～25%）以及转炉钢水终点温度（1 640～1700℃）对渣-钢硫分配比L_S=（S）/[S]的影响。20炉无取向硅钢AGW600生产结果表明,当转炉终点碳氧积控制在0.002 8以内,二元碱度3.2～3.7、转炉钢水终点温度1 675～1 710℃、渣中（FeO）不超过20%,渣-钢硫分配比L_S达7.0,钢水终点[C]为0.025%～0.048%,[S]为0.0024%～0.005 7%,钢材的[C]为0.001 2%～0.002 9%,[S]为0.002 2%～0.004 7%。

Combined with BOF ultra-low sulphur steel development experiment and production practice, the distribu- tion of sulphur content in raw material for BOF is analyzed to get the sulphur content in hot metal with quantity of slag, scrap and lime makes up more than 70% of the total sulphur content in BOF charging. The effect of 150 t BOF top and bot- tom combined blowing converter [ C ] [ O ] products on end slag （FeO） and the effect of blowing time （0 - 15 min）, slag comprehensive basicity R（2 -4）, （FeO） （ 15% - 25% ） and BOF liquid end temperature （ 1 640 - 1 700℃） on slag-steel sulphur partition ratio Ls = （S）/[ S] are studied. Results by 20 heats non-oriented silicon steel AGW600 production show that with controlling BOF end [ C ] [ O ] products within 0. 002 8, binary slag basicity 3.2 - 3.7, BOF liquid end temperature 1 675 - 1 710 ℃ and （FeO） in slag no more than 20%, the slag-steel sulphur partition ratio Ls is up to 7. O, the liquid end [ C] and [ S] are respectively 0. 025% -0. 048% and O. 002 4% -0.005 7% and the steel products [ C] and [ S] are respectively O. 001 2% - 0. 002 9% and 0. 002 2% ～ 0. 004 7%.