retained austenite in trip-assisted steels role of transformation plasticity china steel
Post on 20-Dec-2015
229 views
TRANSCRIPT
![Page 1: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/1.jpg)
Retained Austenite in TRIP-Assisted
Steelsrole of transformation plasticity
China Steel
![Page 2: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/2.jpg)
Shape deformations due to transformations
![Page 3: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/3.jpg)
Fe-30.5Ni-0.32C wt%
Forsik, 2004
Invariant-plane strain
![Page 4: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/4.jpg)
s
1
s
1
1
uniaxial dilatation
simple shear
general invariant-plane
strain
s=0.26
=0.03
![Page 5: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/5.jpg)
Minimum requirement for martensitic transformation
• there must exist an invariant-line at interface
• i.e., one set of dislocations which can glide conservatively
• can be more than one invariant-line
![Page 6: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/6.jpg)
body-centred cubic
cubic close-packed
![Page 7: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/7.jpg)
(a)
BAIN STRAIN
(c) Body-centered
tetragonal austenite
(d) Body-centered
cubic martensite
a
a
a1
2
3 b3
b1 b2
(b)
![Page 8: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/8.jpg)
[100]
[001]
o
aa'
b
b'
o b'
b
a,a'
(a)
(b)
![Page 9: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/9.jpg)
Austenite Martensite (wrong shape)
Twinned Martensite
Slipped Martensite
Twin Boundary
Observed shape, wrong structure
RB
P
LATTICE -INVARIANT DEFORMATION
Correct macroscopic shape, correct structure
(a) (b) (c)
w
x
y
z
w
x
z
y x
w z
y
x
w z
y x
w z
y
P1 2
![Page 10: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/10.jpg)
Bhadeshia & Edmonds, (1980)
Typical composition:
Fe-0.15C-1.5Si-1.5Mn wt%
polycrystalline
![Page 11: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/11.jpg)
Bhadeshia & Edmonds, (1980)
b
![Page 12: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/12.jpg)
Is the shear important in a polycrystalline sample?
![Page 13: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/13.jpg)
How can we bias the microstructure?
By transforming under the influence of stress.
![Page 14: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/14.jpg)
s
1
s
1
1
uniaxial dilatation
simple shear
general invariant-plane
strain
s=0.26
=0.03
![Page 15: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/15.jpg)
![Page 16: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/16.jpg)
![Page 17: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/17.jpg)
![Page 18: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/18.jpg)
50 m
polycrystalline austenite
Bhadeshia, 1982
![Page 19: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/19.jpg)
What is the maximum tensile strain obtained from TRIP?
……in a fully austenitic sample which transforms completely into martensite.
![Page 20: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/20.jpg)
sz3
z1
![Page 21: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/21.jpg)
u v
![Page 22: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/22.jpg)
Sakuma et al. (1991)
![Page 23: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/23.jpg)
abso
rbed
ene
rgy
/ kJ
Yoshitake et al. (1996)
![Page 24: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/24.jpg)
Retained Austenite in TRIP-Assisted
SteelsSlide 1Slide 1…..very small
contribution to elongation.
![Page 25: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/25.jpg)
Bhadeshia & Edmonds, (1980)
Composite of soft and hard phase
![Page 26: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/26.jpg)
Bhadeshia & Edmonds, (1980)
strain in soft phase
Str
ain
in h
ard
phas
e
![Page 27: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/27.jpg)
Tomota (1976)
![Page 28: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/28.jpg)
Bhadeshia & Edmonds, (1980)
![Page 29: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/29.jpg)
low silicon high silicon
Jacques et al. (2001)
silicon causes scale
![Page 30: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/30.jpg)
Summary
• Assistance from TRIP is less than 1.4% of total strain
• Emphasis could be shifted from retained austenite to studies of composite deformation
• Low silicon steels can perform well (Jacques)
![Page 31: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/31.jpg)
![Page 32: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/32.jpg)
![Page 33: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/33.jpg)
![Page 34: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/34.jpg)
![Page 35: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/35.jpg)
![Page 36: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/36.jpg)
![Page 37: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/37.jpg)
Sherif et al. 2003
![Page 38: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/38.jpg)
Sherif et al. 2003
![Page 39: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/39.jpg)
Sherif et al. 2003
![Page 40: Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel](https://reader036.vdocuments.us/reader036/viewer/2022081501/56649d445503460f94a20537/html5/thumbnails/40.jpg)
Sherif et al. 2003