Effect of Nb precipitate coarsening on the high temperature strength in Nb containing ferritic stainless steels

Sim, Gyu Man; Ahn, Jae Cheon; Hong, Sung-Hwa; Lee, Kyung Jong; Lee, Kyung Sub

doi:10.1016/j.msea.2005.01.030

Cited by 160 publications

(72 citation statements)

References 9 publications

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“…The NbC precipitates were very close to each other and the EDX analysis confirmed higher concentrations of Nb and C than the surrounding ferrite matrix. From the literature [15][16][17], it is known that Nb can form Nb(C,N), Fe 2 Nb (Laves phase) and Fe 3 Nb 3 C (M 6 C) particles in Nb-containing ferritic stainless steel.…”

Section: Precipitates Containing Nb and Cmentioning

confidence: 99%

Characterization of NbC and (Nb,Ti)N nanoprecipitates in TRIP assisted multiphase steels

et al. 2011

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Multiphase steels utilising composite strengthening may be further strengthened via grain refinement or precipitation by the addition of microalloying elements. In this study a Nb microalloyed steel comprising martensite, bainite and retained austenite has been studied. By means of transmission electron microscopy (TEM), we have investigated the size distribution and the structural properties of (Nb,Ti)N and NbC precipitates, their occurrence in the various steel phases, and their relationship with the Fe matrix. (Nb,Ti)N precipitates were found in ferrite, martensite, and bainite, while NbC precipitates were found only in ferrite. All NbC precipitates were found to be small (5 -20 nm in size) and to have a face centred cubic crystal structure with lattice parameter a = 4.36 ± 0.05 Å. In contrast, the (Nb,Ti)N precipitates were found in a broader size range (5 -150 nm) and to have a face centred cubic crystal structure with lattice parameter a = 8.09 ± 0.05 Å. While the NbC precipitates were found to be randomly oriented, the (Nb,Ti)N precipitates have a well-defined Nishiyama Wasserman (N-W) orientation relationship with the ferrite matrix. An analysis of the lattice mismatch suggests that the latter precipitates have a high potential for effective strengthening. DFT calculations were performed for various stoichiometries of NbC X and Nb X Ti Y N Z phases and the comparison with experimental data indicates that both the carbides and nitrides are deficient in C and N content.

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Section: Precipitates Containing Nb and Cmentioning

confidence: 99%

Characterization of NbC and (Nb,Ti)N nanoprecipitates in TRIP assisted multiphase steels

et al. 2011

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“…It should be noted that in these studies where Fe 3 Nb 3 C precipitates are observed, [1,3,5,6] the actual C concentration is not determined. In compounds of the filled Ti 2 Ni type, to which the Fe 3 Nb 3 C phase belongs, different light elements in different concentrations can stabilize the same metallic compound.…”

Section: Introductionmentioning

confidence: 94%

“…hexagonal Fe 2 Nb, face-centered-cubic Nb(C,N), and a cubic Fe 3 Nb 3 C phase with prototype Fe 3 W 3 C. According to the work of Sim et al, [5] Nb(C,N) and Fe 2 Nb precipitates coexist in an industrial Fe-15Cr-0.38Nb-0.01C steel after 2 hours heat treatment at 973 K (700°C). After 1000 hours, Fe 3 Nb 3 C precipitates are observed.…”

Section: Introductionmentioning

confidence: 99%

Precipitation in Nb-Stabilized Ferritic Stainless Steel Investigated with in-situ and ex-situ Transmission Electron Microscopy

Malfliet

Mompiou

Chassagne

et al. 2011

Metall Mater Trans A

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“…In comparison with austenitic stainless steel, it is characterized by less linear expansion coefficient, higher strength at elevated temperature, superior thermal fatigue resistance and higher resistance to chloride stress corrosion cracking and cyclic oxidation. Thus, ferrite stainless steel is widely used in the automotive exhaust systems [1][2][3][4][5]. However, traditional ferrite stainless steel has some disadvantages, such as the poor formability and weldability, sensitive to intergranular corrosion.…”

Section: Introductionmentioning

confidence: 99%

Creep behavior of ultra pure ferrite stainless steel 409M

Ying¹,

Liu²,

Chen³

et al. 2015

Proceedings of the 2015 International Conference on Advanced Engineering Materials and Technology

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Abstract. The creep tests have been conducted for ultra pure ferrite stainless steel 409M at 650˚C and the applied stress ranging from 60MPa to 80MPa. The creep deformations and rupture behaviors have been investigated. The results show that a brief primary creep stage is characterized under the condition of test. A larger applied stress caused a higher steady state creep rate and a shorter rupture time at 650˚C. The steady-state creep rate can be described by creep constitutive equation with the creep stress exponent n of 2.34, which shows a creep mechanism involving grain boundary sliding. The creep rupture data show an excellent agreement with the Monkman-Grant relationship. The fracture pattern belongs to transgranular ductile fracture.

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Effect of Nb precipitate coarsening on the high temperature strength in Nb containing ferritic stainless steels

Cited by 160 publications

References 9 publications

Characterization of NbC and (Nb,Ti)N nanoprecipitates in TRIP assisted multiphase steels

Characterization of NbC and (Nb,Ti)N nanoprecipitates in TRIP assisted multiphase steels

Precipitation in Nb-Stabilized Ferritic Stainless Steel Investigated with in-situ and ex-situ Transmission Electron Microscopy

Creep behavior of ultra pure ferrite stainless steel 409M

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