The models of interphase boundaries of austenite/ferrite(γ/α) in the undeformde
austenite and deformed austenite, and the model of 12<1 1 0> ed ge dislocation in austen ite matrix were set up with computer programming. The interfacial energy of γ/ α interphase boundaries in the undeformde austenite and deformed austenite, the envir onment sensitive embedding energies (E ESE) of C, N and microalloyin g
elements Nb , Ti or V (in the form of air mass) in the area of
edge dislocation in austenite were calculated by using recursion method. The refinement mechanism of steels i n the
deformation process was discussed. Interfacial energy calculation results show that the most preferred
ferrite nucleation sites are the area of high densi ty dislocations such as deformation bands, the austenite grain boundaries and su bbounaries, which leads to a considerable increase in the nucleation rate. This is why ferrite
grains formed in the deformed austenite are far more smaller than those in undeformed austenite. The E ESE calculation results show that C,N microalloying elements (Nb, Ti or V) in form of the air mass, C,N together with micro alloying elements (Nb or Ti) in the form air
mass are all easy to aggregate to t he area of edge dialocations, which results in the carbonitride precipitation in there (deformation band, grain boundary or grain subboundary). The growth of fe rrite grains is considerably suppressed by deformation due to impingement with c arbonitride particles and other ferrite grains, which leads to the further refin ement of ferrite grains.
More abstracts about the The study on the ultrafine mechanism of steels: strain-induced phase-transformation form austenite