%0 Journal Article
%A Yang, Mujin
%A King, Daniel. J. M.
%A Povstugar, Ivan
%A Wen, Yuren
%A Luan, Junhua
%A Kuhn, Bernd
%A Jiao, Zengbao
%A Wang, Cuiping
%A Wenman, M. R.
%A Liu, Xingjun
%T Precipitation behavior in G-phase strengthened ferritic stainless steels
%J Acta materialia
%V 205
%@ 1359-6454
%C Amsterdam [u.a.]
%I Elsevier Science
%M FZJ-2021-02139
%P 116542 -
%D 2021
%X A series of G-phase strengthened ferritic stainless steels Fe-20Cr-3Ni-3Si-X (X = 2Mn, 1Mn-2Ti, 1Mn-2Nb and 1Mn-2Ta) are characterized after aging using experimental (microhardness, TEM and APT) and theoretical (DFT) techniques. The results indicate that the Ni16Mn6Si7 G-phase shows sluggish precipitation during aging treatment. This was attributed to the small difference in the enthalpy of formation between the Ni16Mn6Si7 G- and BCC phase and the requirement of high Ni:Fe ratio. A superfine Ni16Ti6Si7 G-phase was found to precipitate as a core accompanied with an “envelope” of Fe2TiSi-L21 Heusler phase during early aging (≤24 h) in the Ti containing alloy. This morphology is predicted to occur due to early Ni clustering in ferrite and a negative Ni concentration gradient away from the cluster that favors Fe2TiSi formation. The G-phases show only particle coarsening without obvious chemical composition evolution for further aging up to 96 h. A prominent hardness increase of 100-275 HV was also observed during aging. These findings provide valuable insight into methods for precipitating low lattice mismatch silicide phases for the development of future high strength steels.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000609936600021
%R 10.1016/j.actamat.2020.116542
%U https://juser.fz-juelich.de/record/892531