Multiple steady state phenomenon
in martensitic transformation
in martensitic transformation
(1. Nonequilibrium Materials Research Institute,
Central South University,Changsha 410083, P.R.China;
2. Institute of Materials Science, Guangxi University,
Nanning 530004, P.R.China)
Central South University,Changsha 410083, P.R.China;
2. Institute of Materials Science, Guangxi University,
Nanning 530004, P.R.China)
Abstract: Based on the basic facts that the martensitic transformation is a physical phenomenon which occurs in nonequilibrium conditions and there exists the feedback mechanism in the martensitic transformation, the dynamical processes of the isothermal and athermal martensitic transformations were analyzed by using nonlinear theory and a bifurcation theory model was established. It is shown thata multiple steady state phenomenon can take place as austenite is cooled, and the transitions of the steady state temperature between the branches of stable steady states can be considered the transformation from austenite to martensite. This model can estimate the starting temperature of the martensitic transformation and explain some experimental features of the martensitic transformation such as the effects of cooling rate, fluctuation and austenitic grain size on the martensitic transformation.
Key words: martensitic transformation； multiple steady states； steady state transition