21Cr超纯铁素体不锈钢TiN析出的热动力学研究  

Thermodynamical analysis of TiN precipitation in 21Cr ultra pure ferrite stainless steel

作　　者：盛捷[1,2] 魏佳富 孟亚惠 李玉峰 马国财 喇培清 SHENG Jie;WEI Jia-fu;MENG Ya-hui;LI Yu-feng;MA Guo-cai;LA Pei-qing(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metal,Lanzhou Univ.of Tech.,Lanzhou 730050,China;Gansu Key Laboratory of Solar Power System Engineering Project,Jiuquan Vocational and Technical College,Jiuquan 735100,China;Gansu Province Special Equipment Inspection and Testing Institute,Lanzhou 730050,China;Jiuquan Iron and Steel Group,Jiayuguan 735000,China)

机构地区：[1]兰州理工大学,省部共建有色金属先进加工与再利用国家实验室,甘肃兰州730050 [2]甘肃省太阳能发电系统工程重点实验室,酒泉职业技术学院,甘肃酒泉735000 [3]甘肃省特种设备检验检测研究院,甘肃兰州730050 [4]酒钢钢铁(集团)有限责任公司,甘肃嘉峪关735100

出　　处：《兰州理工大学学报》2023年第5期1-9,共9页Journal of Lanzhou University of Technology

基　　金：甘肃省在站博士后专项(23JRRA758),甘肃省科技专员专项(23CXGA0015),兰州市科技计划项目(2022-2-80)。

摘　　要：非金属夹杂的数量和尺寸控制对钢铁的加工性能与使役行为有着重要影响.基本凝固理论对21Cr超纯铁素体不锈钢中TiN的析出条件进行数值求解,从理论上研究了TiN的热力学、动力学形成条件与析出规律.结果表明:试验钢钢液中无TiN析出,凝固过程中固液界面前沿发生溶质偏析富集,促使TiN在固相率f_(s)为0.15时开始析出.析出的TiN尺寸受钢液中Ti、N元素初始含量与凝固冷却速率的影响,降低Ti、N初始含量,提升凝固冷却速率均可减小TiN半径,Ti,N元素含量对TiN尺寸影响更加敏感,可通过降低钢液中N元素初始含量延迟凝固过程中TiN夹杂物的析出.实际生产中可调控钢液中Ti的添加量,使得TiN的数量与尺寸分布更加合理.Number density and size distribution of non-metallic inclusion have important influences on processability and service behaviors of steel.The numerical modeling of TiN precipitation condition in 21Cr ultra-pure ferrite stainless steel was solved based on the basic solidification theory.Thermodynamic and kinetic formation conditions and precipitation laws of TiN were investigated theoretically.The findings showed that TiN is precipitated free in molten steel.Ti and N elements solute segregation occurs on the solid/liquid interface in the processing of solidification,which promote TiN precipitation starting as f_(s)=0.15.The precipitate size of TiN is affected by Ti,N content,and cooling rate.TiN radius can be reduced by decreasing the initial content of Ti,N and increasing the solidification cooling rate,Ti,N element contents are more sensitive to the effect of TiN size,so the timing of the precipitation of TiN inclusions during solidification can be significantly delayed by reducing the initial content of N in molten steel.Therefore,the addition amount of Ti in molten steel can be adjusted to make the quantity and size of TiN more reasonable in manufacture.

关 键 词：超纯铁素体不锈钢 TiN析出 固相率 冷却速率 钛氮浓度积 

分 类 号：TF764[冶金工程—钢铁冶金]