铁素体区等温过程中Ti-Mo-Cu微合金钢中的共析出行为  

Co-Precipitation Behavior in Ferrite Region During Isothermal Process in Ti-Mo-Cu Microalloyed Steel

作　　者：唐帅[1] 蓝慧芳[1] 段磊 金剑锋 李建平[1] 刘振宇[1] 王国栋[1] TANG Shuai;LAN Huifang;DUAN Lei;JIN Jianfeng;LI Jianping;LIU Zhenyu;WANG Guodong(State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110819,China;School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,沈阳110819 [2]东北大学材料科学与工程学院,沈阳110819

出　　处：《金属学报》2022年第3期355-364,共10页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.51774083和51774082;中央高校基本科研业务费项目Nos.N2107002和N2107012;高等学校学科创新引智计划项目No.B20029;国家重点研发计划项目No.2017YFB0304402。

摘　　要：碳化物和Cu的共析出是提高微合金钢强度的一种有效手段,本工作利用OM和TEM研究了Ti-Mo-Cu微合金钢在不同等温温度下复合型碳化物和ε-Cu的共析出行为,利用复合析出相固溶析出模型和经典形核长大理论对Ti-Mo-Cu微合金钢的析出动力学进行了计算。结果表明,(Ti,Mo)C与ε-Cu二者独立析出,分别与铁素体基体呈N-W和K-S取向关系,在600℃时析出以ε-Cu为主,620℃发生(Ti,Mo)C与ε-Cu的共析出,而640~660℃时析出以(Ti,Mo)C相间析出为主。热动力学计算表明,在600~660℃范围内,随温度提高,(Ti,Mo)C中的Ti/Mo原子比由2.5增大到4.5,碳化物组成由Ti_(0.71)Mo_(0.29)C演变为Ti_(0.79)Mo_(0.21)C,(Ti,Mo)C与ε-Cu的析出-温度-时间(PTT)曲线存在交点,当温度低于616℃时,ε-Cu优先析出,温度在616℃附近时,发生(Ti,Mo)C与ε-Cu的共析出,当温度高于616℃时,(Ti,Mo)C优先析出,很好解释了实验现象。The coprecipitation of carbides and copper(Cu)particles is an effective technique for strengthening microalloyed steel.In this study,OM and TEM techniques were used to investigate the coprecipitation behavior of carbides and ε-Cu in Ti-Mo-Cu microalloyed steel at different isothermal temperatures.A solid solution precipitation model and the classical nucleation theory of precipitates were used to calculate the precipitation kinetics in the Ti-Mo-Cu microalloyed steel.The results show that(Ti,Mo)C and ε-Cu precipitated independently,and they showed the N-W and K-S orientations with the ferrite matrix,respectively.The dominant precipitates at 600℃ are ε-Cu.(Ti,Mo)C and ε-Cu were coprecipitated at 620℃.At 640-660℃,(Ti,Mo)C was mainly precipitated in the form of interphase precipitation.Thermodynamic calculations showed that in the range of 600-660℃ with an increase in temperature,the Ti/Mo atomic ratio in(Ti,Mo)C increases from 2.5 to 4.5,and the carbide changes from Ti_(0.71)Mo_(0.29)C to Ti_(0.79)Mo_(0.21)C.The precipitation-temperature-time(PTT)curves of(Ti,Mo)C and ε-Cu intersect at 616℃,indicating simultaneous precipitation of(Ti,Mo)C and ε-Cu.(Ti,Mo)C and ε-Cu preferentially precipitate below and above 616℃,respectively.The calculation and experimental results are consistent.

关 键 词：Ti-Mo-Cu 微合金钢 (Ti Mo)C ε-Cu 共析出 析出动力学 

分 类 号：TG142.1[一般工业技术—材料科学与工程]