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 c...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(M_(2)C)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 precipitation 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.展开更多
基金This work was financially supported by the National“13th Five-year Plan”high-tech Research and Development Program of China(YE-17T60270B).
文摘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(M_(2)C)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 precipitation 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.
