精炼渣w(CaO)/w(Al_(2)O_(3))对铝脱氧高强钢夹杂物去除的影响  

Effect of refining slag w(CaO)/w(Al_(2)O_(3))on removal of inclusions in aluminum deoxidized high-strength steel

作　　者：苏赵民 杨文[1] 高志滨 李四军 付常伟 张立峰 SU Zhaomin;YANG Wen;GAO Zhibin;LI Sijun;FU Changwei;ZHANG Lifeng(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Steelmaking Plant,Yinshan Section Steel Co.,Ltd.,Laiwu Iron and Steel Group,Jinan 271104,Shandong,China;Technology Center,Laiwu Branch of Shandong Iron and Steel Co.,Ltd.,Laiwu 271100,Shandong,China;School of Mechanical and Material Engineering,North China University of Technology,Beijing 100144,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]莱芜钢铁集团银山型钢有限公司炼钢厂,山东济南271104 [3]山东钢铁股份有限公司莱芜分公司技术中心,山东莱芜271100 [4]北方工业大学机械与材料工程学院,北京100144

出　　处：《中国冶金》2024年第10期37-46,共10页China Metallurgy

基　　金：国家重点研发计划资助项目(2023YFB3709900,2023YFB3709903);国家自然科学基金资助项目(52174293,U22A20171)。

摘　　要：钢中非金属夹杂物对钢的性能有重要影响,大尺寸夹杂物对钢的性能具有很大破坏性。为了研究在LF精炼工艺中精炼渣w(CaO)/w(Al_(2)O_(3))对铝脱氧高强钢中非金属夹杂物的去除效果,以Q690高强钢为研究对象,开展不同w(CaO)/w(Al_(2)O_(3))精炼渣工业试验并通过热力学计算进行定量分析。3炉精炼渣w(CaO)/w(Al_(2)O_(3))分别为1.58、1.77和2.22,其中w(CaO)/w(Al_(2)O_(3))为2.22的精炼渣对夹杂物去除效果最好。在LF精炼阶段,夹杂物数量密度从13.89个/mm2减小到6.56个/mm2,变化率为53%;面积分数从0.0122%减小到0.0034%,变化率为72%;平均直径从4.82μm减小到3.44μm,变化率为29%。通过引入精炼渣的夹杂物容量Zh数并将其用于含一定固相成分的精炼渣热力学计算,3炉工业试验精炼渣的Zh数分别为0.001940、0.000307和0.000320,由于w(CaO)/w(Al_(2)O_(3))为2.22精炼渣的Zh数最大,其对夹杂物去除效果最好。根据夹杂物容量预测云图,Zh数在渣中CaO质量分数大于55%的液相线上达到最大。在实际生产中为了保证夹杂物去除效果,当精炼渣中SiO_(2)质量分数为15%时,精炼渣w(CaO)/w(Al_(2)O_(3))为2.04~3.05;当精炼渣中SiO_(2)质量分数为10%时,精炼渣w(CaO)/w(Al_(2)O_(3))为1.73~2.22;当精炼渣中SiO_(2)质量分数为5%时,精炼渣w(CaO)/w(Al_(2)O_(3))为1.51~1.55。随着精炼渣中SiO_(2)含量降低,合适的精炼渣w(CaO)/w(Al_(2)O_(3))逐渐减小且范围变小。通过调节精炼渣w(CaO)/w(Al_(2)O_(3)),可为铝脱氧高强钢提供生产指导。Non-metallic inclusions in steel have an important effect on the properties of steel,and large size inclusions have great destructive effects on the properties of steel.In order to study the effect of w(CaO)/w(Al_(2)O_(3))on removal of non-metallic inclusions in aluminum deoxidized high-strength steel in LF refining process,the industrial test of refining slag with different w(CaO)/w(Al_(2)O_(3))was carried out with Q690 high-strength steel as the research object,and the quantitative analysis was carried out by thermodynamic calculation.The w(CaO)/w(Al_(2)O_(3))of the three furnaces were 1.58,1.77 and 2.22,respectively,and the refining slag with w(CaO)/w(Al_(2)O_(3))of 2.22 had the best effect on the removal of inclusions.In the LF refining stage,the number density of inclusions decreased from 13.89/mm2 to 6.56/mm2 with a change rate of 53%,the area fraction decreased from 0.0122%to 0.0034%,the change rate was 72%,and the average diameter decreased from 4.82μm to 3.44μm with a change rate of 29%.By introducing the inclusion capacity Zh of the refining slag and applying it to the thermodynamic calculation of refining slag with certain solid phase composition,the Zh numbers of refining slag in 3 furnaces were 0.001940,0.000307 and 0.000320,respectively.Because the w(CaO)/w(Al_(2)O_(3))of 2.22 refining slag had the largest Zh number,it had the best effect on the removal of inclusions.According to the prediction diagram of inclusion capacity,Zh number reached the maximum in the liquid phase line of slag with CaO mass fraction greater than 55%.In order to ensure the removal effect of inclusions,when the SiO_(2)mass fraction in the refining slag was 15%,the w(CaO)/w(Al_(2)O_(3))in refining slag was 2.04-3.05,when the SiO_(2)mass fraction in the refining slag was 10%,the w(CaO)/w(Al_(2)O_(3))in refining slag was 1.73-2.22,and when the SiO_(2)mass fraction in refining slag was 5%,the w(CaO)/w(Al_(2)O_(3))in refining slag was 1.51-1.55.With the SiO_(2)content decreases in the refining slag,the suitable refining slag w(C

关 键 词：铝脱氧高强钢 精炼渣w(CaO)/w(Al_(2)O_(3)) 工业试验 夹杂物去除 夹杂物容量 

分 类 号：TF769[冶金工程—钢铁冶金]