Atomic-scale characterization of multiple precipitating species in a precipitation-hardened martensitic stainless steel

• 作者: Zhen-bao Liu Zhe Yang Jian-xiong Liang Zhi-yong Yang Guang-min Sheng
• 来源期刊: 钢铁研究学报（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: SHORT COMMUNICATION
• 页码范围: 207-214
• 页数: 8页
• 语种: 英文

摘要

Multiple precipitating species in a 2.2 GPa grade precipitation-hardened martensitic stainless steel with balanced ductility were characterized at atomic scale by atom probe tomography.The results indicated that the clustering of solute atoms was promoted with progressive aging treatments.(Cr,Mo)-rich carbide(M2C)precipitated at the linear dislocations in the as-aged steels.Obvious segregation of Cr,Mo,and C at phase boundaries favored the precipitation of carbide and caused the formation of Cr-lean domains.Spinodal decomposition of martensitic matrix during aging led to the substantial precipi-tation of fine Cr-rich(α'Cr)phase.Compared with the first aging treated samples,a synergistic enhancement of both strength and ductility of the secondary aging treated(SAT)samples was primarily ascribed to the enhanced precipitation of Cr-rich phase.Additionally,Ni-rich filmy reversed austenite precipitated at the lath boundary,which was beneficial to the ductility of SAT samples.