title: Interface segregation behavior in thermal aged austenitic precipitation strengthened stainless steel.
abstract: The segregation of various elements at grain boundaries, precipitate/matrix interfaces were analyzed using atom probe tomography in an austenitic precipitation strengthened stainless steel aged at 750 °C for different time. Segregation of P, B and C at all types of interfaces in all the specimens were observed. However, Si segregated at all types of interfaces only in the specimen aged for 16 h. Enrichment of Ti at grain boundaries was evident in the specimen aged for 16 h, while Ti did not segregate at other interfaces. Mo varied considerably among interface types, e.g. from segregated at grain boundaries in the specimens after all the aging time to never segregate at γ'/γ phase interfaces. Cr co-segregated with C at grain boundaries, although carbides still did not nucleate at grain boundaries yet. Despite segregation tendency variations in different interface types, the segregation tendency evolution variation of different elements depending aging time were analyzed among all types of interfaces. Based on the experimental results, the enrichment factors, Gibbs interface excess and segregation free energies of segregated elements were calculated and discussed.
authors.affiliation: Key Laboratory for Microstructures, Shanghai University, Shanghai 200444, PR China; Technical Department, Jiuli Hi-Tech Metals Co., Ltd., Huzhou 313008, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory for Microstructures, Shanghai University, Shanghai 200444, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Song
authors.affiliation: Key Laboratory for Microstructures, Shanghai University, Shanghai 200444, PR China; Institute of Materials, Shanghai University, Shanghai 200072, PR China. Electronic address: wqliu@staff.shu.edu.cn.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Liu
authors.affiliation: Institute of Materials, Shanghai University, Shanghai 200072, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Xia
authors.affiliation: Institute of Materials, Shanghai University, Shanghai 200072, PR China.
authors.forename: Bangxin
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Technical Department, Jiuli Hi-Tech Metals Co., Ltd., Huzhou 313008, PR China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Su
authors.affiliation: Technical Department, Jiuli Hi-Tech Metals Co., Ltd., Huzhou 313008, PR China.
authors.forename: Wenyan
authors.initials: W
authors.lastname: Ding
keywords: Atom probe tomography; Grain boundary; Phase interface; Precipitation; Segregation; Stainless steel