On the Work-Hardening Mechanism of TWIP Steels Strengthened by Nanometre-Sized Vanadium Carbides
Experiments reveal that while dispersed nanometer-sized vanadium carbides can greatly increase the yield strength of twinning induced plasticity (TWIP) steels, they may cause some reduction of the overall work-hardening rate. A modified physically based model is adopted in the present work to capture the effect of nanometer-sized vanadium carbides on the work-hardening rate of a laboratory FeMnC austenitic TWIP grade. It is found that the introduction of the dispersed nanometer-sized carbides leads to a faster dislocation accumulation rate but reduces the rate of twin formation with strain during plastic deformation. Compared to a reference alloy without precipitates the work-hardening rate is higher at small strains but decreases faster than the reference thus presenting a lower work-hardening rate at high strains.
TWIP steels, Vanadium carbides, Work-hardening, Dislocation evolution, Twinning kinetics
Z.Y. Liang (1), M.X. Huang (1), H.W. Yen (2), C. P. Scott (3)
(1) Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China.
(2) Australian Centre for Microscopy & Microanalysis, The University of Sydney, NSW, 2006, Australia.
(3) Areva NP, 10 rue Juliette Récamier, 69456 LYON, France.
Proceeding of the 2nd International Symposium on Automobile Steel (ISAS2013), 21-24 May 2013, Anshan, China, pp. 113-117