Alloy Manganese Steel Hammer-Alloy Manganese Steel Hammer Manufacturers, Sup
High manganese conference Korea ECCI
15
Düsseldorf, Germany WWW.MPIE.DE [email protected] Dierk Raabe Ivan Gutierrez-Urrutia, Stefan Zaefferer, Dierk Raabe Imaging of dislocations and twins in TWIP steels using electron channeling contrast imaging under controlled diffraction conditions in a scanning electron microscope
-
Upload
dierk-raabe -
Category
Technology
-
view
776 -
download
1
description
Imaging of dislocations and twins in TWIP steels using electron channeling contrast imaging under controlled diffraction conditions in a scanning electron microscope
Transcript of High manganese conference Korea ECCI
Düsseldorf, [email protected]
Dierk Raabe
Ivan Gutierrez-Urrutia, Stefan Zaefferer, Dierk Raabe
Imaging of dislocations and twins in TWIP steels using electron channeling contrast imaging under controlled diffraction conditions
in a scanning electron microscope
Motivation
Electron channeling contrast imaging
Dislocation and twin structures in Fe-22 wt.%Mn-0.6 wt.% C during tensile testing
Conclusions
Overview
2www.mpie.de
Dierk Raabe ([email protected])
3
Kippwinkel
I. Gutierrez-Urrutia, S. Zaefferer, D. Raabe; Scripta Materialia 61 (2009),pp. 737-740I. Gutierrez-Urrutia, S. Zaefferer, D. Raabe; Materials Science and Engineering A 527 (2010), pp. 3552-3560
(1 1-1)
(2 0 0)
(0-2
2)
(-2 0 2)
(1-1 1)
(1 3
-1)
(1 1-1)
(2 0 0)
(0-2
2)
(-2 0 2)
(1-1 1)
(1 3
-1)
(-1-1
1)
(-1 1 1)(0 2 0)
(2-2 0)
(-2 0
2)
(-1-1
1)
(-1 1 1)(0 2 0)
(2-2 0)
(-2 0
2)
(-1-1
1)
(-1 1 1)(0 2 0)
(2-2 0)
(-2 0
2)
EBSD: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
www.mpie.de
Motivation
Electron channeling contrast imaging
Dislocation and twin structures in Fe-22 wt.%Mn-0.6 wt.% C during tensile testing
Conclusions
Overview
4www.mpie.de
Dierk Raabe ([email protected])
0
500
1000
1500
2000
2500
3000
3500
4000
0 0.1 0.2 0.3 0.4 0.5
True stressHardening (MPa)
Har
deni
ng/
Str
ess
(MP
a)
True strain
YS: 210 MPaUTS: 1200 MPaDuctility: 51%strain rate: 2.5x10-4 s-1
tensile test, room temperature10%
20%
40%
TA
twins
TA
step size: 50 nm
EBSD: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
I. Gutierrez-Urrutia et al. Scripta Mater. 61 (2009) 737-740 5
YS: yield strength; UTS: ultimate tensile strength
0
500
1000
1500
2000
2500
3000
3500
4000
0 0.1 0.2 0.3 0.4 0.5
True stressHardening (MPa)
Har
den
ing/
Str
ess
(MP
a)
True strain
YS: 210 MPaUTS: 1200 MPaDuctility: 51%strain rate: 2.5x10-4 s-1
2% 10% 25% 35%
hardening stage: 2%<e< 10%
-Planar slip structures + wavy structures-Few mechanical twins
ECCI: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
I. Gutierrez-Urrutia et al. Scripta Mater. 61 (2009) 737-740 6
YS: yield strength; UTS: ultimate tensile strength
hardening stage: 2%<e< 10%
ECCI: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
I. Gutierrez-Urrutia et al. Scripta Mater. 61 (2009) 737-740 7
0
500
1000
1500
2000
2500
3000
3500
4000
0 0.1 0.2 0.3 0.4 0.5
True stressHardening (MPa)
Har
den
ing/
Str
ess
(MP
a)
True strain
YS: 210 MPaUTS: 1200 MPaDuctility: 51%strain rate: 2.5x10-4 s-1
2% 10% 25% 35%
hardening stage: 10%<e< 25%
-Wavy structures: dislocation cells-Mechanical twins-3 types of grains
ECCI: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
I. Gutierrez-Urrutia, et al. Mater. Sc. Engin. A 527 (2010) 3552 8
YS: yield strength; UTS: ultimate tensile strength
hardening stage: 10%<e< 25%
ECCI: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
I. Gutierrez-Urrutia, et al. Mater. Sc. Engin. A 527 (2010) 3552 9
Type I
hardening stage: 10%<e< 25%
ECCI: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
I. Gutierrez-Urrutia, et al. Mater. Sc. Engin. A 527 (2010) 3552 10
Type II
ECCI: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
I. Gutierrez-Urrutia, et al. Mater. Sc. Engin. A 527 (2010) 3552 11
hardening stage: 10%<e< 25%
Type III
ECCI: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
I. Gutierrez-Urrutia, et al. Mater. Sc. Engin. A 527 (2010) 3552 12
hardening stage: 10%<e< 25%
Message:Not only isotropic:
BUT: implement in tensorial solver
5th hardening stage:
35%<e< 50%
ECCI: Work hardening of TWIP steels, Fe-22Mn-0.6C (wt%)
I. Gutierrez-Urrutia, et al. Mater. Sc. Engin. A 527 (2010) 3552 13
Motivation
Electron channeling contrast imaging
Dislocation and twin structures in Fe-22 wt.%Mn-0.6 wt.% C during tensile testing
Conclusions
Overview
14www.mpie.de
Dierk Raabe ([email protected])
ECCI: excellent for mapping dislocations, twins, and interactions at wide field of view
Mean free dislocation path and strain hardening determined by deformation twin spacing
<111>//deformation axis: multiple twins, planar dislocation fields, cells
<112>//deformation axis: single twin dominance, planar dislocation fields, cells
<001>//deformation axis: wavy dislocation substructures, no twins
0.1 true strain: less than 20% of all grains contain deformation twins
0.3 true strain: 90% of all grains contain deformation twins
Orientation dependence: type I grains: low deformation twinning activity; type II grains: well-developed twin substructure along one active twinning system (primary twin system); type III grains: well-developed twin substructure along more than one active twinning system (primary and secondary twin systems).
Overview
15www.mpie.de
