Analysis of the γ–ɛ–α′ variant selection induced by 10% plastic deformation in 304 stainless steel at −60°C

Modelling the microstructure of martensitic steels

“…They demonstrated the selection of particular variants by comparing the measured pole figure with calculated pole figures for all 24 crystallographic variants of martensite. Humbert et al [6] calculated the crystallographic texture of an austentic stainless steel transformed into bcc martensite in two stages. They assumed that the austenite first evolved to − martensite which eventually transformed into α −martensite.…”

“…[6]. However the correct procedure for calculating U is the model of Patel and Cohen [2], because the strain associated with martensitic transformation is plastic [7].…”

“…5 shows the results for an austenitic stainless steel that is studied in Ref. [6]. The values of the interaction energies for the same austenite grain orientation are calculated using the procedure describe in Ref.…”

“…The interactions between martensite and these stresses affects the mechanical free energy of the individual variants depending on their crystallographic orientation and will produce an energy which adds to the chemical driving force. Variant selection occurs when the interaction energy is large enough compared to the chemical free energy ∆G [5,6].…”

“…Humbert et al [6] used a method based on the elasticity theory rather than the plastic model of Patel and Cohen [2]. However, since the transformation strain is plastic, the plastic work explained in Ref [2] gives the correct value of interaction energy [5].…”