DH36高强度船板钢中碳化物及碳氮化物析出行为  

Precipitation behaviors of carbides and carbonitrides in DH36 high-strength ship plate steel

作　　者：石骁[1,2] 吴建中 郭汉杰[1,2] 郭靖 段生朝[1,2] 杨文晟 SHI Xiao;WU Jianzhong;GUO Hanjie;GUO Jing;DUAN Shengchao;YANG Wensheng(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials,Beijing 100083,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]高端金属材料特种熔炼与制备北京市重点实验室,北京100083

出　　处：《中南大学学报（自然科学版）》2018年第3期518-528,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(U1560203;51274031)~~

摘　　要：利用碳复型法通过透射电子显微镜研究工业级DH36高强度船板钢在控轧控冷工艺下纳米级碳化物和碳氮化物的析出行为,并针对钢液冷却过程分别对碳化物及氮化物的析出规律进行热力学计算。研究结果表明:钢中普遍存在的析出相为(Nb,Ti)(C,N)碳氮化物和(Nb,Ti)C碳化物,均为FCC,Na Cl型结构,其中(Nb,Ti)(C,N)基本呈立方形,(Nb,Ti)C大多由富Ti的"核"部和富Nb的"帽"部构成;析出粒子均为单相,其晶格常数随Ti与Nb物质的量比的变化而微弱变化;通过统计粒子粒径及分布规律,利用Orowan绕过机制计算得出此类钢中沉淀强化对屈服强度的贡献约为166 MPa;钢中第二相析出的先后顺序为Ti N,Ti C,Nb C,Nb N。To study the precipitation of nano-sized carbides and carbonitrides in technical grade DH36 high-strength ship plate steel during the thermomechanical controlled processes(TMCP),carbon replications of DH36 were explored through a transmission electron microscopy.And the precipitation of carbides and nitrides during the cooling process was further investigated thermodynamically.The results show that the common precipitated phases in steels are(Nb,Ti)C carbides and(Nb,Ti)(C,N)carbonitrides,both of which are face-centered cubic of NaCl structure.The(Nb,Ti)(C,N)carbonitrides are mostly cubic,and the(Nb,Ti)C carbides are mainly constituted by Ti rich core part and Nb rich cap part.The precipitates are single phase,and the lattice constant transforms slightly with the alteration of molar ratio of Ti to Nb.Through the statistics of particle size and distribution,a calculation based on Orowan mechanism shows that the precipitation hardening offers 166 MPa yielding strength increase.The precipitation sequence is as follows:TiN,TiC,NbC,NbN.

关 键 词：DH36 碳化物 碳氮化物 沉淀强化 析出热力学 

分 类 号：TG142.41[一般工业技术—材料科学与工程]