炼钢

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弹簧钢LF精炼渣系优化与工业试验

  

  1. (1. 北京科技大学 钢铁冶金新技术国家重点实验室,北京 100083;2. 杭州钢铁集团公司,浙江 杭州 310022)
  • 接受日期:1900-01-01 出版日期:2015-08-05

Optimization of LF refining slag of spring steel and industrial tests

  • Accepted:1900-01-01 Online:2015-08-05

摘要: 用氮氧分析、荧光分析、扫描电镜能谱等方法,对某厂“100 t EAF→LF→VD→CC”工艺流程条件下生产的弹簧钢进行了T.O含量、精炼渣成分以及铸坯中夹杂物的形貌、尺寸和成分分析;在此基础上,应用FactSage热力学计算软件进行热力学计算,对精炼渣进行优化研究。结果表明:优化后的精炼渣系的主要成分为:w(CaO)=36 %~44 %,w(SiO2)=36 %~44 %,w(Al2O3)<10 %,w(MgO)=9 %~11 %;碱度R=0.8~1.2,同时使用该渣系进行工业试验,夹杂物的塑性得到极大的改善,进入低熔点区的夹杂物比例由改进前的12.5 %增加至75 %,且平均尺寸减小到1.48 μm,未观察到大于2.5 μm的夹杂物。

关键词: 弹簧钢, LF精炼渣, 夹杂物塑性

Abstract: With total oxygen and nitrogen content analysis, X-ray fluorescence, scanning electronic microscope (SEM), and energy dispersive X-ray spectroscopy (EDS), the total oxygen mass fractions, components of LF refining slag, and shapes, sizes, and components of inclusions in billets of spring steel produced by “100 t EAF→LF→VD→CC” process in a domestic steel factory were analyzed. And based on this, thermodynamic calculation was also carried out by using FactSage software to optimize present refining slag. The results showed that the main composition of refining slag after optimization was below: w(CaO)=36 %-44 %,w(SiO2)=36 %-44 %,w(Al2O3)<10 %,w(MgO)=9 %-11 % and basicity was around 0.8-1.2. Applying this new refining slag in industrial tests, inclusion plasticity was promoted and the percentage of inclusions which enter the lowmeltingpoint area increases from 12.5 % to 75 %. Besides, the average size of inclusions decreases to 1.48 μm and the inclusions whose sizes were over 2.5 μm had not been observed.

Key words: spring steel, LF refining slag, inclusion plasticity