1. Design of TRIP-Assisted Steels for Automobiles

2. Microstructure has been extensively studied Microstructure understood: most aspects can be calculated Mechanical properties cannot be calculated Mechanical properties badly related to microstructure

3. Bhadeshia & Edmonds, (1980) Typical composition: Fe-0.15C-1.5Si- 1.5Mn wt%

4. Bhadeshia & Edmonds, (1980)   b

5. Swallow & Bhadeshia, 1996

6. engineering strain engineering stress / MPa Mizui et al. (1997)

9. Jacques et al. (2001)

10. Ro et al. (1994)

12. transformation-induced plasticity 50  m

14.  s 1 s 1  1 uniaxial dilatation simple shear general invariant-plane strain s=0.26  =0.03

15. c r  s 1 Transformation is a deformation on habit plane Can be induced by stress

16. Bhadeshia, 1982

19.  50  m polycrystalline austenite Bhadeshia, 1982

20.  s z3z3 z1z1

21. u v

22. Sakuma et al. (1991)

23. absorbed energy / kJ Yoshitake et al. (1996)

24. Bhadeshia & Edmonds, (1980) Composite of soft and hard phase

25. Bhadeshia & Edmonds, (1980) strain in soft phase Strain in hard phase

26. Tomota (1976)

27. Bhadeshia & Edmonds, (1980)

28. Chester and Bhadeshia, 1997

33. low silicon high silicon Jacques et al. (2001) silicon causes scale

34. 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)