A new model for the volume fraction of martensitic transformations

Abstract

A model using an energy balance is proposed to describe the volume fraction of multiple-interface martensitic transformations. For martensitic transformations without external stresses at quenching temperature T Ͻ M s , the volume fraction of martensite () is proportional to the undercooling (M s Ϫ T) and inversely proportional to a linear function of the quenching temperature (T); thus, ϭwhere ␤ is a material constant. For stress-induced martensitic transformations under stress with temperature T Ͼ M s , the relationship is ϭ 0 [1 Ϫ ( Ϫ a a ik ik ik )] Ϫ1 , where 0 is the initial detectable amount of martensite formed at martensitic starting stress Ms ik and is a material constant. It is found that the results obtained from this model are in good M s ik ik agreement with experimental results.

Martensitic transformation in AISI D2 tool steel during continuous cooling to 173 K

“…Also, as indicated in Figs.1d and 2d, a contractive strain is observed during soaking at austenitizing temperature. The source of this strain can be attributed to chemical inhomogeneity caused by the dissolution of carbides or the stabilization of retained austenite because of the slow cooling [23,34]. The presence of the contraction observed in this study indicates that part of the austenite phase has a higher strength level.…”

“…austenite to martensite transformation) which are translated into variation of the specific volume of the specimen [22,23]. However, it is not always possible to detect with precision the amount of volume change during the transformation as well as transformation start and finish points.…”

Evaluation of models for martensitic transformation and TRIP via comparison of experiments and simulations

“…To take a stress influence into account, some modifications of K-M were proposed. A different approach can be found in [4]. We briefly review the models used here.…”

“…l Yu [4] proposed a model being different to the models above. It involves the martensite-finish temperature h mf (= -174 C, in our case) and reads as…”

Autocatalysis, Entropic Aspects and the Martensite Transformation Curve in Iron-Base Alloys

“…The formal description of martensitic transformation kinetics remains an active topic in steel research, now exceeding nearly a century of interest [1][2][3][4][5][6][7][8][9][10][11][12] . The equations predicting this phenomenon invariably contain fitting parameters.…”