Role of interfaces in duplex stainless steel deformation micromechanisms

Abstract

Elementary fatigue deformation mechanisms in duplex stainless steel bicrystals are studied by transmission electron microscopy (TEM). Attention is paid to the interaction between lattice dislocations and ferrite/austenite interfaces depending upon the orientation relationship (plastically compatible or incompatible) and the initial deformation (in the α-phase or in the γ -phase). Furthermore, an attempt is made to understand the behaviour under mechanical solicitation of each phase in the bicrystal and to compare it with the single crystal deformation behaviour.

Plastic Deformation Quantified by Atomic Force Microscopy Measurements for Duplex Stainless Steel under Monotonic and Cyclic Loading

“…It was found that there was good agreement between the measured EBSD data and the calculated angles when type F1 slip bands were considered in the ferrite phase but poor agreement when the austenite was considered. It can be concluded that type F1 slip bands originate from bulk plasticity in the ferrite in agreement with other authors [8,11]. The ability for dislocations in a DSS to transfer from austenite to ferrite depends on their crystallographic compatibility [11,12,13].…”

The effect of the embrittlement on the fatigue limit and crack propagation in a duplex stainless steel during high cycle fatigue

“…On the contrary, if a is higher than 10°, the dislocations cannot cross the phase boundary and plastic deformation is accumulated in the first phase -usually the austenite, until a stress concentration occurs at the phase boundary. In a recent study, Taisne et al [13] observed the role of interfaces in fatigue deformation mechanism in DSS bicrystal and stated that phase boundary geometry and elasticity affect the dislocation transmission process. Moreover, Marinelli et al [14,15] studied the Kurdjumov-Sachs crystallographic orientation relations between austenite and ferrite in DSS and proposed that the efficiency of the coupling between phases seems to play an important role in the crack formation process.…”

Fatigue crack initiation behavior in embrittled austenitic–ferritic stainless steel

“…As a consequence, the plastic strain localization and the fatigue crack initiation behavior are affected. Taisne et al [17] in a recent study on the role of interfaces in fatigue deformation mechanism in DSS bicrystals observed that not only phase boundary geometry and elasticity impose the dislocation transmission process, but also the presence of interface modifies the response of each crystal to the mechanical solicitation. Alvarez-Armas et al [7] conclude that the efficiency of the coupling between phases seems to play an important role in the crack formation process.…”