【作者】 李宗强；

【导师】 薛正良；

【作者基本信息】 武汉科技大学 ， 钢铁冶金， 2006， 硕士

【摘要】 硫对钢材的危害性很大。硫不仅能引起钢的热脆,而且对钢的热加工性能、力学性能、焊接性能、耐腐蚀性能、成型性以及冷镦性能都有很大的负面作用,所以脱硫一直是冶金工作者研究的重点之一。针对邯郸三炼钢100t BOF-130t LF脱硫生产现状,由于没有铁水预处理操作,出钢钢水硫含量高。单独采用LF精炼工艺,脱硫任务重,精炼周期长,冶炼低碳钢,特别是冶炼冷轧低碳钢时,LF炉在脱硫的同时,增硅增碳的现象较严重,影响了产品的最终性能和合格率。因此,在出钢过程中使用预熔渣并利用出钢动力学条件进行渣洗脱硫,将精炼炉的部分脱硫任务在出钢过程中完成,降低进LF钢水的硫含量,从而减轻了LF的脱硫负担。此外,使用的预熔渣经混冲后在LF精炼过程中所形成的精炼渣,还应具备较强的脱硫能力。在实验室配制铝酸钙预熔渣并进行脱硫实验。结果表明:该渣不添加CaF2脱硫效果更好。并得到该渣的成分最佳配比:CaO55%,Al2O340%,SiO23%,MgO2%。该渣系具有良好的脱硫效果,脱硫率达到85%。随后在邯郸三炼钢100t BOF-130t LF炉上进行预熔渣脱硫的工业试验。采用的预熔试验渣分为两种:预熔渣Ⅰ和预熔渣Ⅱ。结合现场生产数据,分析影响渣洗脱硫的因素,得到以下结论:(1)转炉终点钢水[C]含量直接影响终点钢水氧含量,终点钢水[C]含量高,有利于脱硫;(2)在相同的脱硫条件下,转炉终点[S]含量越高,渣洗脱硫率也越高;初始硫含量越低,渣洗过程脱硫也越困难;(3)预熔渣CaO含量对其本身的光学碱度和硫容量影响很大。在基本相同的加渣量下,预溶渣Ⅰ的CaO含量比预溶渣Ⅱ高出2%,平均渣洗脱硫率却从6.17%升高到16.79%;(4)增加渣洗用预熔渣量对提高渣洗脱硫率十分有利;(5)转炉出钢挡渣质量对渣洗脱硫产生影响;(6)LF出站渣光学碱度高、LF进站钢中[S]含量大和预熔渣加入量多均能提高LF精炼的脱硫效果。更多还原

【Abstract】 Sulphur has large hurmfulness on the steel products.Not only it generate hot brittleness,also it can cause much negative impact on hot-working character, mechanical property,welding performance,resistant character, processability and cold- heading.So desulfurization is one of the study subject by metallurgists at all times.On 100t BOF-130t LF of Handan NO.3 steel works,with LF refining technology alone,for heavy desulfurization mission and long refining cyclic,the phenomenon of increasing silicium and carbon is much serious on refining low carbon steel specially the cold-rolling low carbon steel.The results impact the products’final performance and percent of pass.So applicating wash heat with premelting slag of high desulfurization efficiency and dynamics condition,part of desulfurization mission is completed on tapping process,the sulphur content of molten steel is decreased before entering LF,and the desulfurization mission is relieved on LF.Refining slag,which made of premelting slag must have great desulfurization capability on LF after wash heat.Calcium aluminate premelted slag is prepared for the desulfurization experiment. The result show that this slag’s desulfurization effect is better without CaF2. And its best component preparation as:CaO55%,Al2O340%,SiO23%,MgO2%. It has good desulfurization effect,and the desulfurization efficiency reaches 85%.The desulfurization commercial test is proceeded on 100tBOF-130tLF of Handan NO.3 steel works.The premelted slag is bifurcated asⅠandⅡ.The desulfurization infuence factor of wash heat is analysed combined the delivry data,and the conclusion is obtained as:(1) The carbon content affects the oxygen content in the molten steel of inconverter terminal. The larger the carbon content is, the more advantageous the desulfurization is.(2) Under the identical desulfurization condition,the larger the sulphur content is,the higher the desulfurization efficiency of wash heat is,and the fewer the sulphur content is,the more difficult the desulfurization is.(3) The slag’s optical alkalinity and sulphur capability is influenced badly by the CaO content. Compared slagⅠandⅡ,with the CaO content is increased by 2% ,the average desulfuri- zation efficiency rises from 6.17% to 16.79%.(4) Large quantity of slag is advantageous on increasing desulfurization efficiency of wash heat.(5) Desulfurization of wash heat is influenced by the skimming quality on converter tapping.(6) Desulfurization effect on LF is increased with the high optical alkalinity of exit-station, large sulphur cotent of enter-station and large quantity of refining slag.更多还原