Severly Deformed Steels

Acknowledgments Professor J. R. Yang Dr Han-Shen Wang Dr Hiroshi Harada

Severely deformed two-phase mixture Severely deformed austenite Theory and predictions Future

theoretical tensile strength 21 GPa Brenner, 1956

dual phase steel

Hono, 2002

Atom probe image of Scifer, individual atoms visible Atom probe image of Scifer, 5.5 GPa steel wire Bhadeshia and Harada, 1993

mechanical mixing m o Fe free energy of ferrite Fe x x x a a¢ carbon

0.2C - 1.2Si - 1.5Mn wt% 0.9C - 2.3Si - 1.5Mn at%

Scifer, 5.5 GPa and ductile Kobe Steel

Precipitate ?

stainless steel thread

316L

as-received longitudinal transverse

austenite martensite

distance moved by dislocations plastic strain distance moved by dislocations dislocation density shear stress

grain size

Stress due to Driving Force balance:

mechanical stabilisation when:

50 µm