Normal and excess nitrogen uptake by iron-based Fe–Cr–Al alloys: the role of the Cr/Al atomic ratio

Jung, Keum‐Dong; Schacherl, R. E.; Bischoff, E.; Mittemeijer, E. J.

doi:10.1080/14786435.2011.563760

Cited by 13 publications

(3 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with recent reports by Mittemeijer and colleagues on the gaseous nitriding of Fe-Al-Cr alloys. [17][18][19] They also found that (Cr, Ti) mixed nitrides are formed in the nitriding of Fe-Cr-Ti alloys. [20] Both V and Ti atoms have a strong affinity with N atoms.…”

Section: Discussionmentioning

confidence: 92%

“…[16] It has been reported that mixed nitrides are precipitated in the nitriding of Fe-Cr-Al [17][18][19] and Fe-Cr-Ti alloys. [20] Schwarz et al [21] very recently investigated the nitriding behavior of an Fe-Si-V alloy and reported that VN forms in the early stage of nitriding, and after some incubation time, Si 3 N 4 is precipitated separately.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Surface Hardening and Nitride Precipitation in the Nitriding of Fe-M1-M2 Ternary Alloys Containing Al, V, or Cr

Miyamoto

Suetsugu

Shinbo

et al. 2015

Metall Mater Trans A

View full text Add to dashboard Cite

Surface Hardening and Nitride Precipitation in the Nitriding of Fe-M1-M2 Ternary Alloys Containing Al, V, or Cr GORO MIYAMOTO, SHOTARO SUETSUGU, KUNIO SHINBO, and TADASHI FURUHARA Nitride precipitation and resultant surface hardening in nitrided Fe-M1-M2 ternary alloys containing Cr, Al, or V were investigated using transmission electron microscopy and three-dimensional atom probe tomography. The (Al, Cr) and (Cr, V) mixed nitrides are formed by the co-precipitation of these elements during the nitriding of Fe-Al-Cr or Fe-Cr-V alloys. However, the precipitation of V nitrides precedes Al nitride precipitation during the nitriding of the Fe-Al-V alloy, which results in two-step hardening behavior. The addition of Cr or V to the Fe-Al alloy accelerates the precipitation kinetics of Al nitrides by promoting the nucleation of Al nitrides, which leads to substantial surface hardening.

show abstract

Section: Discussionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Surface Hardening and Nitride Precipitation in the Nitriding of Fe-M1-M2 Ternary Alloys Containing Al, V, or Cr

Miyamoto

Suetsugu

Shinbo

et al. 2015

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…[14,15] Recent studies reported by Mittemeijer and coworkers have shown the importance of the so called "excess" nitrogen on the diffusion process. [16,17,18,19] Such increased nitrogen concentrations represent the atomic fraction surpassing the quantity that should be expected in case that: (i) the alloying elements are fully consumed to form nitrides and (ii) the nitrogen equilibrium solubility in an unstrained iron matrix is achieved. The nitriding of AISI H13 hot work tool steel has also been intensively studied leading to enhanced surface hardness, thermal fatigue, and corrosion resistance.…”

Section: Introductionmentioning

confidence: 99%

Nanosized precipitates in H13 tool steel low temperature plasma nitriding

Zagonel

Bettini

Basso

et al. 2012

Surface and Coatings Technology

View full text Add to dashboard Cite

A comprehensive study of pulsed nitriding in AISI H13 tool steel at low temperature (400°C) is reported for several durations. X-ray diffraction results reveal that a nitrogen enriched compound (-Fe 2-3 N, iron nitride) builds up on the surface within the first process hour despite the low process temperature. Beneath the surface, X-ray Wavelength Dispersive Spectroscopy (WDS) in a Scanning Electron Microscope (SEM) indicates relatively higher nitrogen concentrations (up to 12 at.%) within the diffusion layer while microscopic nitrides are not formed and existing carbides are not dissolved. Moreover, in the diffusion layer, nitrogen is found to be dispersed in the matrix and forming nanosized precipitates. The small coherent precipitates are observed by High-Resolution Transmission Electron Microscopy (HR-TEM) while the presence of nitrogen is confirmed by electron energy loss spectroscopy (EELS). Hardness tests show that the material hardness increases linearly with the nitrogen concentration, reaching up to 14.5 GPa in the surface while the Young Modulus remains essentially unaffected. Indeed, the original steel microstructure is well preserved even in the nitrogen diffusion layer. Nitrogen profiles show a case depth of about ~43 m after nine hours of nitriding process. These results indicate that pulsed plasma nitriding is highly efficient even at such low temperatures and that at this process temperature it is possible to form thick and hard nitrided layers with satisfactory mechanical properties. This process can be particularly interesting to enhance the surface hardness of tool steels without exposing the workpiece to high temperatures and altering its bulk microstructure.

show abstract

Formation Mechanisms of Alloying Element Nitrides in Recrystallized and Deformed Ferritic Fe-Cr-Al Alloy

Akhlaghi

Meka

Jägle

et al. 2016

Metall Mater Trans A

View full text Add to dashboard Cite

The effect of the initial microstructure (recrystallized or cold-rolled) on the nitride precipitation process upon gaseous nitriding of ternary Fe-4.3 at. pct Cr-8.1 at. pct Al alloy was investigated at 723 K (450°C) employing X-ray diffraction (XRD) analyses, transmission electron microscopy (TEM), atom probe tomography (APT), and electron probe microanalysis (EPMA). In recrystallized Fe-Cr-Al specimens, one type of nitride develops: ternary, cubic, NaCl-type mixed Cr 1Àx Al x N. In cold-rolled Fe-Cr-Al specimens, precipitation of two types of nitrides occurs: ternary, cubic, NaCl-type mixed Cr 1Àx Al x N and binary, cubic, NaCl-type AlN. By theoretical analysis, it was shown that for the recrystallized specimens an energy barrier for the nucleation of mixed Cr 1Àx Al x N exists, whereas in the cold-rolled specimens no such energy barriers for the development of mixed Cr 1Àx Al x N and of binary, cubic AlN occur. The additional development of the cubic AlN in the cold-rolled microstructure could be ascribed to the preferred heterogeneous nucleation of cubic AlN on dislocations. The nitrogen concentration-depth profile of the cold-rolled specimen shows a stepped nature upon prolonged nitriding as a consequence of instantaneous nucleation of nitride upon arrival of nitrogen and nitride growth rate-limited by nitrogen transport through the thickening nitrided zone.

show abstract

Normal and excess nitrogen uptake by iron-based Fe–Cr–Al alloys: the role of the Cr/Al atomic ratio

Cited by 13 publications

References 45 publications

Surface Hardening and Nitride Precipitation in the Nitriding of Fe-M1-M2 Ternary Alloys Containing Al, V, or Cr

Surface Hardening and Nitride Precipitation in the Nitriding of Fe-M1-M2 Ternary Alloys Containing Al, V, or Cr

Nanosized precipitates in H13 tool steel low temperature plasma nitriding

Formation Mechanisms of Alloying Element Nitrides in Recrystallized and Deformed Ferritic Fe-Cr-Al Alloy

Contact Info

Product

Resources

About