en سایر موضوعات Other subjects Research Paper Research Paper <span style="font-size:12pt"><span style="line-height:200%"><span style="text-autospace:none"><span new="" roman="" style="font-family:" times=""><span style="font-size:11.5pt"><span style="line-height:200%">Deformation-induced </span></span><i><span style="font-size:14.0pt"><span style="line-height:200%">&alpha;</span></span></i><span style="font-size:11.5pt"><span style="line-height:200%">΄-martensite generally forms at shear bands in the coarse-grained austenite, while it nucleates at grain boundaries in the ultrafine-grained (UFG) austenite. The available kinetics models are related to the nucleation on the shear band intersections, and hence, their application to investigating the kinetics of </span></span><i><span style="font-size:14.0pt"><span style="line-height:200%">&alpha;</span></span></i><span style="font-size:11.5pt"><span style="line-height:200%">΄-martensite formation for the UFG regime cannot be justified. Accordingly, in the present work, the general Johnson&ndash;Mehl&ndash;Avrami&ndash;Kolmogorov (JMAK-type) model was implemented for comparing the kinetics of </span></span><i><span style="font-size:14.0pt"><span style="line-height:200%">&alpha;</span></span></i><span style="font-size:11.5pt"><span style="line-height:200%">΄-martensite formation in the UFG and coarse-grained regimes using an AISI 304L stainless steel. On the experimental front, the X-ray diffraction (XRD) patterns and the electron backscattered diffraction (EBSD) maps were used for phase and microstructural analyses, respectively. It was revealed that the simple JMAK-type model, by considering the dependency of the volume fraction of </span></span><i><span style="font-size:14.0pt"><span style="line-height:200%">&alpha;</span></span></i><span style="font-size:11.5pt"><span style="line-height:200%">΄-martensite on the strain, is useful for modeling the experimental data, predicting the nucleation sites based on the theoretical Avrami exponents, and characterizing the transformation kinetics at low and high strains.</span></span></span></span></span></span> Metastable austenitic stainless steels,Grain size,Transformation-induced plasticity,Kinetics of phase transformations,Johnson–Mehl–Avrami–Kolmogorov model 1 9 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-911-2&slc_lang=en&sid=1 Mohammad Javad Sohrabi mj.sohrabi.ut@gmail.com 1800319475328460018162 1800319475328460018162 No University of Tehran Hamed Mirzadeh hmirzadeh@ut.ac.ir 1800319475328460018163 1800319475328460018163 Yes University of Tehran Saeed Sadeghpour Saeed.Sadeghpour@oulu.fi 1800319475328460018164 1800319475328460018164 No University of Oulu Reza Mahmudi mahmudi@ut.ac.ir 1800319475328460018165 1800319475328460018165 No University of Tehran