摘要
本文通过渣金平衡试验,借助冶金学原理、FactSage热力学计算、扫描电镜观察等理论和方法,研究了3种不同组元含量CaF_(2)-Al_(2)O_(3)-CaO-MgO-TiO_(2)-ZrO_(2)六元渣系及5个不同渣金平衡时间(20、40、60、120、180 min)下C-HRA-3合金中元素含量及夹杂物特征的变化。结果表明,渣金平衡试验后,C-HRA-3合金中Al、Ti、Zr含量降低,Si含量上升,而B含量保持小范围波动。预熔渣中TiO_(2)和ZrO_(2)含量增加,可明显减轻合金中Ti、Zr烧损,而Al含量变化较小。当平衡时间在0~40 min时,Al、Ti含量分别降低了14.29%和20.59%,Zr含量变化幅度最大,迅速降低了54.55%;而平衡时间超过40 min时,Al、Ti、Zr含量在较低水平波动变化。渣金平衡时间延长可使C-HRA-3合金中夹杂物数量减少,对夹杂物平均直径及不同粒径数量比例影响不大,其类型主要为球形或近球形的Al_(2)O_(3)和Mg O及棱角状Ti N夹杂,且在凝固过程易析出大尺寸一次碳化物。研究表明,在电渣重熔冶炼生产C-HRA-3合金的过程中应严格控制渣中SiO_(2)等杂质含量并适当添加TiO_(2)和ZrO_(2)组元,注意过程中Al含量的补加及冶炼保护气氛良好,提高电渣锭的冷却强度。
In this paper,the changes in element content and inclusion characteristics in C-HRA-3 alloy under three different6-system slags,CaF_(2)-Al_(2)O_(3)-CaO-MgO-TiO_(2)-ZrO_(2),and five different slag-metal equilibrium times of 20~180 min were investigated by metallurgical principles,FactSage thermodynamic calculations and scanning electron microscopy.The results show that the contents of Al,Ti and Zr in the C-HRA-3 alloy decrease,while the content of Si increases,and the B content maintains a small range of fluctuations after the slag-metal equilibrium experiment.When the equilibrium reaction time is within 0~40 min,the contents of Al and Ti are 14.29%and 20.59%,respectively,lower than the original content,and the Zr content changes maximally and decreases by 54.55%.As the equilibrium time exceeds 40 min,the contents of Al,Ti and Zr fluctuate at a low level.The increase in equilibrium time can reduce the number of inclusions in the C-HRA-3 alloy and has little effect on the average diameter of inclusions and the proportion of different sizes.The inclusions mainly consist of spherical or near-spherical Al_(2)O_(3) and MgO and Ti N with edges and corners.Moreover,large primary carbides easily precipitate from the matrix during solidification.Through research and analysis,SiO_(2) and other impurities should be strictly controlled in the slag,and TiO_(2) and ZrO_(2) components should be properly added to the slag in the process of electroslag remelting of C-HRA-3 alloy.It is necessary to add Al into the metal bath,maintain a good smelting protective atmosphere and improve the cooling intensity of the electroslag ingot.
作者
李龙飞
林腾昌
何西扣
陈正宗
姚同路
孟华栋
LI Longfei;LIN Tengchang;HE Xikou;CHEN Zhengzong;YAO Tonglu;MENG Huadong(Department of Metallurgical Technology Research,Central Iron and Steel Research Institute,Beijing 100081,China;Institute for Special Steels,Central Iron and Steel Research Institute,Beijing 100081,China)
出处
《铸造技术》
CAS
2022年第10期882-888,共7页
Foundry Technology
基金
中央企业自主投入研发专项重大基金(事20T61180ZD)。
关键词
C-HRA-3合金
电渣重熔
渣金平衡
元素烧损
夹杂物
C-HRA-3 alloy
electroslag remelting
slag-metal equilibrium
element burning loss
inclusion
