TY  - JOUR
AU  - Yang, Mujin
AU  - King, Daniel. J. M.
AU  - Povstugar, Ivan
AU  - Wen, Yuren
AU  - Luan, Junhua
AU  - Kuhn, Bernd
AU  - Jiao, Zengbao
AU  - Wang, Cuiping
AU  - Wenman, M. R.
AU  - Liu, Xingjun
TI  - Precipitation behavior in G-phase strengthened ferritic stainless steels
JO  - Acta materialia
VL  - 205
SN  - 1359-6454
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2021-02139
SP  - 116542 -
PY  - 2021
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000609936600021
DO  - DOI:10.1016/j.actamat.2020.116542
UR  - https://juser.fz-juelich.de/record/892531
ER  -