摘要
为研究淬火轨冶炼过程中典型夹杂物的变化规律,进一步提高钢中非金属夹杂物控制水平,以国内某钢厂“150 t转炉炼钢→150 t LF精炼→VD脱气→280 mm×380 mm方坯连铸”工艺生产的淬火轨为研究对象,对冶炼过程系统取样,结合氧氮分析、钢液成分分析以及钢中非金属夹杂物分析,从夹杂物成分、数密度和尺寸等方面研究其变化规律。研究结果表明,淬火轨冶炼过程氧氮含量和夹杂物数密度持续降低,夹杂物去除效果明显;LF进站钢中典型夹杂物主要成分为SiO_(2)-MnO-Al_(2)O_(3),主要是转炉采用硅锰脱氧合金化产生的脱氧产物;LF合金化后典型夹杂物主要成分为CaO-SiO_(2)-Al_(2)O_(3)-MgO,夹杂物中CaO和Al_(2)O_(3)含量显著升高,SiO_(2)和MnO含量降低,主要是合金辅料带入的Ca和Al_(s)与钢中的溶解氧或氧化物夹杂发生反应所致,MgO含量升高与钢包耐火材料侵蚀有关;LF出站钢中典型夹杂物主要成分为CaO-SiO_(2)-Al_(2)O_(3)-MgO,夹杂物中CaO和MgO含量升高,Al_(2)O_(3)含量降低,主要是钢渣反应以及钢液和耐火材料作用向钢液传递的结果;铸坯内弧1/4处典型夹杂物内核为Al_(2)O_(3)-MgO,外层为Al_(2)O_(3)-SiO_(2)-CaO;受合金辅料的加入以及夹杂物的生成与夹杂物的聚集上浮等诸多因素影响,夹杂物尺寸在一定范围内随时间呈周期性波动。LF和VD阶段,由于软吹促使夹杂物聚集上浮,夹杂物数密度降低、尺寸增大;中间包内夹杂物尺寸较稳定,连铸过程由于夹杂物碰撞聚集,使铸坯中夹杂物尺寸明显增大;轧制过程中部分尖晶石类夹杂物发生脆断,导致夹杂物平均尺寸降低,而数量略有增加。因此,严格控制硅铁和硅钙钡中的Al_(s),以及辅料中其它杂质含量,对提高淬火轨洁净度有重要作用。
In order to study the change law of typical inclusions in the smelting process of quenching rails and further improve the control level of non-metallic inclusions in steel,the quenching rail produced by the"150 t converter steelmaking→150 t LF refining→VD degassing→280 mm×380 mm billet continuous casting"process of a domestic steel mill was taken as the research object,and the smelting process system was sampled,combined with oxygen and nitrogen analysis,molten steel composition analysis and non-metallic inclusion analysis in steel,and its change law was studied from the aspects of inclusion composition,numerical density and size.The results show that the oxygen and nitrogen content and the density of inclusions in the quenching rail smelting process continue to decrease,and the effect of inclusion removal is obvious.The main component of the typical inclusions in LF inlet steel is SiO_(2)-MnO-Al_(2)O_(3),which is mainly the deoxidation product produced by the converter using silicon manganese deoxidation alloying.The main component of the typical inclusions after LF alloying is CaO-SiO_(2)-Al_(2)O_(3)-MgO,the content of CaO and Al_(2)O_(3) in the inclusions is significantly increased,and the content of SiO_(2) and MnO is reduced,mainly due to the reaction of Ca and Al_(s) brought into the alloy accessories with dissolved oxygen or oxide inclusion in the steel,and the increase in MgO content is related to the erosion of the ladle refractory material.The main component of the typical inclusions in LF outbound steel is CaO-SiO_(2)-Al_(2)O_(3)-MgO,and the content of CaO and MgO in the inclusions is increased,and the content of Al_(2)O_(3) is decreased.It is mainly the result of the reaction of steel-slag and the transfer to molten steel after the reaction of molten steel and refractory.The typical inclusion core at inner arc 1/4 of the casting blank is Al_(2)O_(3)-MgO,and the outer layer is Al_(2)O_(3)-SiO_(2)-CaO.Affected by the addition of alloy accessories and the generation of inclusions and the aggregati
作者
朱君
杨吉春
樊志明
谌智勇
ZHU Jun;YANG Jichun;FAN Zhiming;CHEN Zhiyong(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China;Steelmaking Plant of Inner Mongolia Baotou Steel Co.,Ltd.,Baotou 014010,China)
出处
《炼钢》
CAS
北大核心
2022年第6期52-57,共6页
Steelmaking
关键词
淬火轨
脱氧产物
典型夹杂物
耐火材料
洁净度
quenched rail
deoxidation product
typical inclusions
refractory material
cleanliness
