E690海工钢中复合碳化物(Nb,Ti,Mo,V)C在奥氏体中的沉淀析出行为研究  

Precipitation behavior of composite carbides of(Nb,Ti,Mo,V)C in austenite of E690offshore steel

作　　者：姚娜[1] 兴超 YAO Na;XING Chao(School of Materials Engineering,Jiyuan Vocational and Technical College,Jiyuan 459000,China)

机构地区：[1]济源职业技术学院材料工程学院,河南济源459000

出　　处：《轧钢》2025年第1期29-34,共6页Steel Rolling

基　　金：河南省高等学校重点科研项目计划(19B45003)。

摘　　要：海工钢中第二相析出物的类型、析出量、尺寸大小、形貌特征和分布对其综合性能有较大影响。基于复合析出相在奥氏体中的固溶析出计算和经典析出动力学理论,系统研究了复合析出相在E690海工钢奥氏体中的析出行为,并探讨了轧制过程中奥氏体形变储能对复合析出相在奥氏体中析出动力学的影响。结果表明:E690海工钢中MC碳化物在1184.5℃开始析出,主要为(Nb,Ti,Mo,V)C;在奥氏体相区,MC碳化物最大析出质量分数为0.0574%,最大析出体积分数为0.000727%,主要为NbC和TiC;复合碳化物(Nb,Ti,Mo,V)C在不同形核机制下的临界形核尺寸随温度的降低而减小,发生晶界形核的临界形核功小于位错形核和均匀形核,(Nb,Ti,Mo,V)C最先在晶界形核,发生均匀形核、晶界形核和位错形核时的最快沉淀析出温度分别为820.5、908.7、818.3℃;随着形变储能的增加,复合碳化物(Nb,Ti,Mo,V)C相对形核率呈增加趋势,析出孕育期明显缩短,复合析出相的沉淀强化作用增强。The type,amount,size,morphological characteristics and distribution of the second precipitate in offshore steel have a significant impact on its comprehensive performance.Based on the calculation of solid solution precipitation of composite precipitates and classical precipitation kinetics theory,the precipitation behavior of composite precipitates in austenite of E690offshore steel were systematically studied,and the effect of deformation energy storage on the precipitation kinetics of composite precipitates in austenite were also discussed.The results showed that(Nb,Ti,Mo,V)C in E690offshore steel would precipitate at 1184.5℃.In austenite phase region,the maximum precipitation mass fraction of MC carbides was 0.0574%,and the maximum precipitation volume fraction was 0.000727%,of which NbC and TiC accounted for the main part.The critical nucleation size of(Nb,Ti,Mo,V)C decreased with the decreasing temperature under different nucleation mechanisms,and the critical nucleation work for grain boundary nucleation was smaller than that for dislocation nucleation and uniform nucleation.(Nb,Ti,Mo,V)C preferentially undergone grain boundary nucleation,and the fastest precipitation temperatures for uniform nucleation,grain boundary nucleation and dislocation nucleation were 820.5℃,908.7℃and 818.3℃,respectively.With the increase of deformation energy storage,the relative nucleation rate of(Nb,Ti,Mo,V)C increased,the precipitation incubation period shortened,and the precipitation strengthening effect of composite precipitates improved.

关 键 词：E690海工钢 (Nb Ti Mo V)C 析出动力学 形核机制 形变储能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]