Precipitation behavior in G-phase strengthened ferritic stainless steels
Source abstract
Abstract
Abstract 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.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Hydrogen embrittlement and corrosion behaviors in metals · Microstructure and Mechanical Properties of Steels · High Temperature Alloys and Creep
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (41)
Show source-provided references
1. Crystal chemistry of the G-phases in the {Ti, Zr, Hf}-Ni-Si systems10.1016/j.jssc.2006.11.031 ↗
2. On the crystal structure of the Mn-Ni-Si G-phase10.1016/j.jallcom.2008.01.142 ↗
3. Non-uniform phase separation in ferrite of a duplex stainless steel10.1016/j.actamat.2017.08.044 ↗
4. Characterization of the intermetallic G-phase in an AISI 329 duplex stainless steel10.1023/A:1018669217124 ↗
5. Study of phase transformation and mechanical properties evolution of duplex stainless steels after long term thermal ageing (>20 years)10.1016/j.jnucmat.2011.01.036 ↗
6. Kinetics of G-phase precipitation and spinodal decomposition in very long aged ferrite of a Mo-free duplex stainless steel10.1016/j.jnucmat.2015.06.017 ↗
7. G-phase precipitation in austenitic stainless steel deformed by high pressure torsion10.1016/j.msea.2012.05.030 ↗
8. The two-step nucleation of G-phase in ferrite10.1016/j.actamat.2016.06.013 ↗
9. In situ TEM study of G-phase precipitates under heavy ion irradiation in CF8 cast austenitic stainless steel10.1016/j.jnucmat.2015.04.042 ↗
10. A new complex phase in a high-temperature alloy10.1038/178208b0 ↗
11. The formation of G-phase in 20/25 Nb stainless steel AGR fuel cladding alloy and its effect on creep properties10.1007/BF01086484 ↗
12. Precipitation study in Ti-stabilised austenitic stainless steel after 207,000 h of service10.1080/09603409.2018.1546919 ↗
13. Microstructural study of the NbC to G-phase transformation in HP-Nb alloys10.1016/j.mtla.2020.100593 ↗
14. Influences of Mo/Zr minor-alloying on the phase precipitation behavior in modified 310S austenitic stainless steels at high temperatures10.1016/j.matdes.2017.04.095 ↗
15. G-phase precipitation in duplex stainless steels after long-term thermal aging: A high-resolution transmission electron microscopy study10.1016/j.jnucmat.2014.05.069 ↗
16. Accurate determination of the number density of G-phase precipitates in thermally aged duplex stainless steel10.1080/14786435.2012.674222 ↗
17. Developement of High-Strength Martensite by Age-Hardening of Coherent Intermetallic Precipitates
18. Aging behaviour of cobalt free chromium containing maraging steels10.1179/mst.1992.8.6.546 ↗
19. Small-angle neutron scattering analysis of the precipitation behaviour in a maraging steel10.1107/S0021889803000293 ↗
20. G phase precipitation and strengthening in ultra-high strength ferritic steels: towards lean ‘maraging’ metallurgy10.1016/j.actamat.2017.03.032 ↗
21. G-phase strengthened iron alloys by design10.1016/j.actamat.2019.11.007 ↗
22. A novel ferritic steel family hardened by intermetallic compound G-phase10.1016/j.msea.2018.11.148 ↗
23. Microstructural evolution and precipitation strengthening in a new 20Cr ferritic trial steel10.1016/j.msea.2018.05.027 ↗
24. New insights into the precipitation strengthening of ferritic steels: nanoscale G-phase particle10.1016/j.matlet.2017.07.078 ↗
25. Atom probe specimen preparation with a dual beam SEM/FIB miller10.1016/j.ultramic.2007.02.023 ↗
26. Software VASP, vienna (1999)
27. From ultrasoft pseudopotentials to the projector augmented-wave method10.1103/PhysRevB.59.1758 ↗
28. High-precision sampling for Brillouin-zone integration in metals10.1103/PhysRevB.40.3616 ↗
29. Generalized gradient approximation made simple10.1103/PhysRevLett.77.3865 ↗
30. The formation and structure of Fe-Mn-Ni-Si solute clusters and G-phase precipitates in steels10.1016/j.jnucmat.2018.03.050 ↗
31. The formation and structure of Fe-Mn-Ni-Si solute clusters and G-phase precipitates in steels10.1016/j.jnucmat.2018.03.050 ↗
32. Odette · 1995
33. Thermodynamic and kinetic modeling of Mn-Ni-Si precipitates in low-Cu reactor pressure vessel steels10.1016/j.actamat.2017.07.021 ↗
34. On the elevated temperature thermal stability of nanoscale Mn-Ni-Si precipitates formed at lower temperature in highly irradiated reactor pressure vessel steels10.1038/s41598-019-45944-z ↗
35. Thermodynamic models of low-temperature Mn-Ni-Si precipitation in reactor pressure vessel steels10.1557/mrc.2014.21 ↗
36. Density functional theory study of the magnetic moment of solute Mn in bcc Fe10.1103/PhysRevB.98.024418 ↗
37. Specific features of the properties of half-metallic ferromagnetic Heusler alloys Fe2MnAl, Fe2MnSi, and Co2MnAl10.1134/S1063783415040149 ↗
38. Study of the effect of Ni on solute clustering in α-Fe10.1016/j.nimb.2019.05.077 ↗
39. The effect of Ni on the microstructural evolution of high Cu reactor pressure vessel steel welds after thermal ageing for up to 100,000 h10.1016/j.msea.2018.08.063 ↗
40. Radiation induced bcc-fcc phase transformation in a Fe3%Ni alloy10.1016/j.actamat.2018.08.031 ↗
41. Embrittlement of RPV steels: An atom probe tomography perspective10.1016/j.jnucmat.2007.05.003 ↗