Atom probe tomography characterization of Cu-rich phases in HSLA steels
- 作者：LIU QingdongGU JianfengLIU Wenqing
- 会议时间：2013-06-01
- 关键词：Cu precipitation ; atom probe tomography ; HSLA steel ; diffusion
- 作者单位：LIU Qingdong(Shanghai Key Laboratory of Materials Laser Processing and Modification,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Laboratory for Microstructures and Institute of Materials,School of Materials Science and Engineering,Shanghai University,Shanghai 200072,China)GU Jianfeng(Shanghai Key Laboratory of Materials Laser Processing and Modification,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)LIU Wenqing(Laboratory for Microstructures and Institute of Materials,School of Materials Science and Engineering,Shanghai University,Shanghai 200072,China)
- 母体文献：第五届宝钢学术年会论文集
- 会议名称：第五届宝钢学术年会
- 会议地点：上海
- 主办单位：中国金属学会
- 语种：chi
摘要
Precipitation hardening is one of the most prevailing methods to strengthen alloy steels.The nature of Cu precipitation reaction is of fundamental scientific interest and technologically important.The nanometer sized Cu-rich precipitates and carbides in quench - tempered HSLA steels are studied at atomic scale by atom probe tomography ( APT).The results indicate that Cu-rich precipitates greatly correlate with carbides in aspect of distributional characters,i.e.,the two phases are prone to co-precipitate on the dislocations and interfaces ( low angle boundaries of martensite laths).These crystallographic defects have a significant effect on the sizes,morphology and composition of Cu-rich precipitates with Ni and Mn segregation shell.The Ni-rich clusters but Ni- Mn clusters are detected,which act as preferential nucleation sites for Cu-rich precipitates.Besides,the Ni segregation at the Cu-rich precipitate /matrix heterophase interface contribute to fast growth of the Cu-rich precipitates.This can be attribute to high diffusion rate of Cu and Ni at these sites.It is concluded that Ni additions facilitate the Cu precipitation and indirectly contribute to strength of HSLA steels.