Mechanism of ferrite nucleation induced by Y_(2)O_(2)S inclusion in low carbon steel  

作　　者：Hai-hui Zhang Hui-hui Xiong Jing Qin Jian-bo Zhang 

机构地区：[1]Faculty of Materials,Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China [2]National Rare Earth Functional Material Innovation Center,Ganzhou 341000,Jiangxi,China

出　　处：《Journal of Iron and Steel Research International》2023年第6期1291-1299,共9页

基　　金：supported by NSFC(No.52074135);Jiangxi Provincial Natural Science Foundation(No.20224ACB214011);Youth Jinggang Scholars Program in Jiangxi Province(QNJG2020049);Ganzhou Key Scientific and Technological Research and Development Plan.

摘　　要：To reveal the mechanism of ferrite nucleation induced by Y_(2)O_(2)S inclusion in steel,the work of adhesion,interfacial energy,structure stability and electronic properties of Fe(111)/YY_(2)O_(2)S(001)interfaces with various terminations were first investigated using the first-principles calculations.Secondly,the steels with and without yttrium were prepared,while the rare earth yttrium-based inclusions in low carbon steel were characterized using an electron probe micro-analyzer,and the grain size of steel was analyzed using a scanning electron microscope with electron backscattered diffraction.The results show that the bonding strength of Fe/Y_(2)O_(2)S interfaces with S-and Y-terminations is stronger than that of the interface with O-terminations.The Fe-hcp-S interfaces with S-termination have the highest work of adhesion(4.01 J/m2)and the lowest interface distance(1.323A).The Fe-hcp-S interface exhibits the highest stability,and its interfacial bonding force is mainly attributed to the strong hybridization of Fe-3d and S-2p orbitals in the energy range of-7.5-0 eV.Moreover,the interfacial energy of Fe-hcp-S is substantially lower than those of the ferrite(s)/Fe(L)interface and the ferrite-austenite interface,suggesting that Y_(2)O_(2)S inclusions in steel can efficiently promote ferrite nucleation.The experimental observations demonstrate that the ferrite grain size of steel containing 0.03 wt.% Y is much more refined than that of the steel without yttrium,and the average grain size of steel with and without Y is 102 and 258μm,respectively.This indicates that the results of our calculations match with experimental findings.

关 键 词：Ferrite nucleation INCLUSION Interfacial energy First-principles calculation REFINEMENT 

分 类 号：TG142[一般工业技术—材料科学与工程]