铝镇静钢钙处理后碰撞行为对Al_2O_3夹杂物变性的作用  

Effects of Collision Behavior on Al_2O_3 Based Inclusion Modification After Calcium Treatment for Aluminium-Killed Steel

作　　者：郭靖[1] 程树森[1] 程子建[1,2] 张英伟[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]酒泉钢铁(集团)有限责任公司,甘肃嘉峪关735100

出　　处：《钢铁》2013年第9期37-44,共8页Iron and Steel

摘　　要：对铝镇静钢LF精炼钙处理后不同时期取钢样,通过SEM-EDS观察钢样中夹杂物,分析钙处理后铝镇静钢中夹杂物变性机制,并提出了一种夹杂物变性的碰撞机制:在钙处理后,由于钙浓度在钙气泡周围较高形成了CaO类夹杂物,其与钢液中已有的Al2O3类夹杂物相互碰撞结合在一起,然后二者发生化学反应变性为低熔点的液态夹杂物。通过相图分析从理论上指出:Al2O3类夹杂物可与CaO通过碰撞变性,且其变性机制和控速环节与Al2O3类夹杂物通过与钙发生还原反应的变性不同。夹杂物碰撞使变性速率大大加快,几分钟之内即可良好变性。在本次试验中,约有21%的Al2O3类夹杂物通过与CaO碰撞发生变性。实验室试验和其他研究者的工业试验结果均证明:在二次精炼过程中,通过往钢包中喂入CaO类粉末可以使Al2O3夹杂物变性。The steel samples were taken out at different time after calcium-treatment, and the inclusion information in them was monitored by SEM combined with EDS to understand how Al2O3 inclusions were modified during LF refining especially after calcium-treatment for aluminium-killed steel. Another collision mechanism for Al2O3 inclusion modification was proposed： CaO based inclusions precipitate after calcium treatment due to higher calcium concentration around calcium bubble, and then CaO based inclusions and Al2O3 based inclusion collide together and further react with each other and finally form liquid calcium aluminates. In addition, it points out theoretically that Al2O3 based inclusion could be modified by colliding with CaO based on phase diagram analysis and the mechanism. And the mechanism and rate-controlling step differ from that of Al2O3 based inclusion modification by reduced reaction with calcium. The modification rate of this manner is much fast that Al2O3 based inclusion could be modified well in several minutes. Approximating 21% of Al2O3 based inclusion is modified in this manner in present trials. Finally, it is verified by laboratorial experiment and other researchersr industrial trials that blowing CaO based powder can also modify Al2O3 based inclusion during secondary refining.

关 键 词：夹杂物 钙处理 变性 碰撞 LF精炼 

分 类 号：TF704.7[冶金工程—钢铁冶金]