Factors determining twinning in martensite

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

“…The results obtained in the present investigation are in agreement with the above reports as no trace of midrib was observed in TEM micrographs (Fig.5a-b) and internal nano-twins were present in the microstructure (Fig.6a-d). It is well known that low s M temperatures promote the formation of twins [45]. For the investigated alloy, it was calculated that in the range 325 K -173 K, 15 % to 22 % of austenite transforms to martensite, respectively (Figs.…”

“…Martensitic transformation is always accompanied with plastic deformation and the dominant deformation mode in austenite could be modified by changes in critical resolved shear stress [34,45]. The presence of a significant amount of nano-twins observed on the martensite produced during cooling indicates that, under these conditions, the critical resolved shear stress for twinning is lower than the one for slip and therefore austenite to martensite transformation is promoted in expense of slip.…”

A Simple Method for Observing <i>ω</i>-Fe Electron Diffraction Spots from <112>_<i>α</i>-Fe Directions of Quenched Fe–C Twinned Martensite

“…[1][2][3][4][5][6][7][8][9][10] It was suggested that low M s (martensite start temperature) favors the formation of the twinned structure. 1,[11][12][13] In Fe-C system, low M s corresponds to the alloy with high carbon content. Such a suggestion matches well with the experimental observations in high carbon alloys in which the twinning structure is the only martensitic substructure.…”