等温マルテンサイト変態に起因する超塑性変形の解析

抄録

A phenomenological theory of superplastic deformation due to isothermal martensitic transformation, constituted of the mechanical constitutive equation and the transformation kinetics, is presented. The transformation kinetics is obtained by modifying the one for the diffusion-type transformation proposed by the present authors. The T-T-T diagrams constructed by the transformation kinetics explain well the qualitative characteristics of the experimental results in Fe-Ni-Mn, Fe-Ni-Cr and Fe-Ni alloys. The proposed theory is shown to be able to describe well the transformation superplastic behavior in Fe-Ni alloy, the stress and temperature dependences of the overall deformationtime behavior, the final accumulated strain and the incubation time of deformation.