摘要
为了研究重轨钢全流程非金属夹杂物的行为演变,进一步控制重轨钢中夹杂物,提高产品质量。以U75V重轨钢为研究对象,通过对LF-VD-CC工艺重轨钢生产全流程系统取样,结合氧氮分析、钢液成分分析、非金属夹杂物分析以及热力学计算,从夹杂物化学成分、数量及尺寸等方面研究其演变过程。结果表明,U75V重轨钢生产全流程氧氮含量持续降低,最终TO、[N]质量分数分别约为0.001 0%和0.004 0%;LF进站主要为MnO-SiO2-Al2O3型夹杂物,为脱氧产物;LF精炼化渣后,MnO-SiO2-Al2O3型夹杂物转化为CaO-SiO2-Al2O3型夹杂物,BaCaSi和FeSi等合金辅料带入的Ca、Als是产生该结果的主要原因;LF离站时主要为CaO-SiO2-Al2O3-MgO型夹杂物,夹杂物中CaO和MgO含量增加;VD精炼过程CaO-Al2O3-MgO型夹杂物基本消失,VD破空至铸坯中主要为CaO-SiO2-Al2O3型夹杂物;钢轨中镁铝尖晶石类夹杂物比例增加,为CaO-SiO2-Al2O3-MgO型夹杂物,热力学计算结果表明钢轨中尖晶石类夹杂物为降温冷却过程中形成,且计算值与实际值总体吻合。
In order to study the behavior evolution of non-metallic inclusions in heavy rail steel,further control the inclusions of steel and improve product quality.The evolution of chemical composition,quantity,size,etc.of nonmetallic inclusions was investigated from an example U75 Vheavy rail steel based on sampling during the production process of the LF-VD-CC route,combined with oxygen and nitrogen analysis,molten steel composition analysis,non-metallic inclusion analysis and thermodynamic calculation.The results show that the oxygen and nitrogen content in the production of U75 Vheavy rail steel process continues to decrease,and the final TO and[N]mass fraction are about 0.001 0%and 0.004 0%respectively.MnO-SiO2-Al2O3 type of inclusions are the main inclusions at LF start,which originated from deoxidation product.After the slagging,the MnO-SiO2-Al2O3 inclusions are converted into CaO-SiO2-Al2O3 type,and the Ca and Alsbrought by the alloying materials such as BaCaSi and FeSi are the main reasons for the result.When leaving the LF station,the inclusions are CaO-SiO2-Al2O3-MgO with CaO and MgO content increased.CaO-Al2O3-MgO inclusions disappeared during VD refining,and CaO-SiO2-Al2O3 was mainly found in samples from VD vacuum broken to bloom.The proportion of inclusions of magnesium-aluminum spinel in the rail increases,and which is CaO-SiO2-Al2O3-MgO type of inclusions.The thermodynamic calculation results show that the spinel inclusions in the rail are formed during cooling process,and the calculated value is consistent with the actual value.
出处
《中国冶金》
CAS
北大核心
2018年第S1期83-89,共7页
China Metallurgy
基金
国家重点研发计划专项资助项目(2016YFB0300102,2017YFB0304000,2017YFB0304001)
国家自然科学基金资助项目(51725402,51504020,51704018)
中央高校基本科研业务费专项资金资助项目(FRF-TP-17-001C2,FRF-TP-15-001C2,FRF-TP-15-067A1,FRF-TP-17-039A1)
北京市科技计划资助项目(Z171100002217063)
广西重点研发计划资助项目(AB17129006)
中国科协青年人才托举项目资助项目(2017QNRC001)
博士后创新人才支持计划资助项目(BX201700028)
中国博士后基金资助项目(2017M620016)
关键词
U75V重轨钢
非金属夹杂物
行为演变
U75V heavy rail steel
non-metallic inclusions
behavior evolution
