SKD11Property of the Fe-15Mn-10Al-1C Alloy
*1 1 1 2
Chung-Chun Wu, Cheng-Feng Yang, Wei-Yang Chang, Wei-Chih Chen
1.
2.
:06-2427001 E-mail:
[email protected]
(Fe,Mn)3AlCx
γα+κ γκ´+β-Mn
γκ´+D03 B2α+D03
575~600
Fe-15Mn-8Al-1C
(Fe,Mn)3AlCx
was the mixture of ferrite and austenite phases.
TEM examinations revealed that (Fe,Mn)3AlCx
carbides precipitated within the austenite matrix ,
and (B2+D03) ordered phases could be found
within the ferrite region by the mechanism of
α→α+B2→α+D03 ordering transition. This
result indicated that the increase of Al addition
in the Fe-Mn-Al-c alloy would enhance both the
formation of ordered phases with the ferrite
matrix and precipitation of κ-carbides within the
austenite matrix.
aged at 650 for 24 hours, phase decompositi-
on of γ→κ´+B2 could be observed on the auste-
nite grain boundary. It is worthwhile to note that
the γ→κ´+B2 transformation was quite different
from γ→α+κ´, γ→κ´+D03 and γ→κ´+β-Mn by
other workers.
the narrow range of 575 and 600, which
was also quite different from the α+B2→α+D03
transition observed in the Fe-Mn-Al-C alloy
before by other researchers.
Compared with Fe-15Mn-8Al-1C alloy ,
surface hardness property. In addition to the
mixture of ferrite and austenite phases, the main
reason may be both the formation of ordered
phases within the ferrite region and the
precipitation of (Fe,Mn)3AlCx carbides
the rapidly quenching process.
KeywordFe-Mn-Al-C alloy, dual-phase
phases, (Fe,Mn)3AlCx carbides,
Fe-15Mn-10Al-1C
80A/cm 2 ~120A/cm
(holder)
X
1050
(twin)
XRD
Fe-15Mn-10Al-1C
BCC FCC
condition. (F: ferrite matrix; A: austenite matrix)
Fig.2 XRD patterns of the Fe-15Mn-10Al-1C
alloy in the as-quenched condition.
23.8 °30.8° 34.1°
JCPDS 65-0543
(Fe,Mn)3AlCx (κ ) 2θ 23.8°
34.1° (100) (110)
3.7Å 2θ 30.8°
B2 D03d
B2(100) D03 (200)
B2 D03
TEM 3
(a)(b) Fe-15Mn-8Al-1C 1050
as-quenched condition.(a) and (b) show [100]
and [011] SADPs of the ferrite region.
[001]
-10Al -1C alloy in the as-quenched condition ;(a)
(200) D03 DF electron micrograph taken from
the ferrite region; (b) (200) D03 DF micrograph at
larger magnification.
D03 D03
10nm
α+ D0 3
α → α + B2 → α + D03
Fe-15Mn-10Al-1C alloy in the as-quenched
condition, taken from the same ferrite region
as Fig. 4(a) and 4(b)
1050
1050
50 nm
Fe-15Mn-8Al-1C alloy in the as-quenched
condition. (a) The zone axes were (a) [001] and
[011] directions, respectively.(hkl: anstenite ; hkl:
κ- carbide)
72 XRD
XRD
Fig.7 TEM electron micrographs taken from the
austenite matrix of the Fe-15Mn -8Al-1C alloy
in the as-quenched condition. (a) BF
micrograph; (b) DF micrograph
D03 (111)
450 72 2θ 26.7°
D03
CC FCC
B2D03(Fe,Mn)3AlCx
D03
alloy aged at 450 for 72 hours.
TEM
450 24
(α+ D03)
450 24
κ ()
Fig.9. TEM electron micrographs of the Fe-15Mn-10
Al-1C alloy aged at 450 for 24 hours. (a)
SADP taken from the ferrite region, the zone
axis is [011] direction. (b) (200) D03 DF
micrograph; (c) (111) D03 DF micrograph.
Fig10. TEM electron micrographs of the
Fe-15Mn-10Al-1C alloy aged at 450 for 24
hours. (a) BF electron micrographs taken from
the austenite matrix (b)(100) κ-carbide DF
electron micrograph taken from austenite matrix.
,
FCC B2D03
(Fe,Mn)3AlCx (κ)
450 κ
20nm , 450
,
(b)(200) D03
(α+ D03)
24 TEM
D03 B2
Fe-15Mn -10Al-1C 550
24 (α + D03)
B2
24
κ , 550
,κ
,
→ κ + α
Fe-15Mn-10Al-1C alloy aged at 550 for 24
hours, (a)(200) D03 DF electron micrographs
taken from ferrite region(b) (100) D03 DF
micrograph taken from the same region as
Fig.11(a)
600 24
(111) D03
(200) D03 B2
24 hours.(a) (111) D03 DF taken from
ferrite region(b) (200) D03 DF taken from
the same ferrite region as Fig.12(a).
Fig13. Optical micrograph of the Fe-15Mn-10-
Al -1C alloy aged at 650 for 24 hours.
( F : ferrite matrix; A: austenite matrix)
B2
(α + D03)
575 600
550
24
B2
D03 D03
(α + B2) 15 (a) Fe-15Mn
-10Al-1C 650 24
D03
α + B2
10Al-1C alloy aged at 650 for 24 hours. (a)
and (b) show (200) D03 DF and (111)DF D03 DF
electron micrographs ,respectively.
(α + B2)
Fe-15Mn-10Al-1C alloy aged at 650 for 24
hours (a)BF electron mircograph taken from the
austenite grain boundary.(b) SADP taken from
the region near by κ -carbides. (c) (111) D03 DF
electron micrograph.
Fe-15Mn-10Al-1C
κ
450
D03
, 550 and 650 for 24 hours on the
surface hardness property of the (a)
Fe-15Mn-10Al-1C alloy, (b) Fe-15Mn-8Al
D03
(200)D03
B2D03
γ→κ´+D03
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