Introduction and point groups

1
Introduction and point groups Stereographic
projections Low symmetry systems Space
groups Deformation and texture Interfaces,
orientation relationships Homogeneous
deformations Slip, twinning and invariant-plane
strains
2
Similarity transformation
3
homogeneous deformation leaves points originally
in a line, colinear, and lines originally in a
plane, coplanar
4
similarity transformation
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
stretch and rotation
13
(No Transcript)
14

• Refinement of austenite grain size
• repeated recrystallisation
• pancaking

• Refinement of ferrite grain size
• nucleation and growth

15
Smallest size possible in steel ?
16
(No Transcript)
17
Yokota Bhadeshia, 2004
18
(No Transcript)
19
Pancaking
20
courtesy Rongshan Qin, GIFT, POSTECH
Singh Bhadeshia, 1998
21
v Su
u
v
22
(No Transcript)
23
(No Transcript)
24
(No Transcript)
25
Cross Rolling
second pass
rotate 90
x
first pass
y
y
x
26
(No Transcript)
27
(No Transcript)
28
(No Transcript)
29
(No Transcript)
30
courtesy of Rongshan Qin
31
Chae, Qin, ISIJ International 49 (2009) 115
32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
36
TWIP steel
37
B. Qin, MST 28 (2008) 969
38
correspondence matrix