Twinning and martensite in a 304 austenitic stainless steel

Studying Mechanical Properties and Micro Deformation of Ultrafine-Grained Structures in Austenitic Stainless Steel

“…In addition, the directions of all deformation twins were nearly perpendicular to that of ε martensite, which is consistent with the results of Li et al [14], who reported that deformation twins grow along the direction perpendicular to ε martensite with increasing deformation. In fcc metals, stacking faults and deformation twins can be dissociated from a screw dislocation or a 60 • dislocation [13]. Stacking faults overlapped within the (111) γ plane of the fcc crystal, which promoted the generation of deformation twins [24].…”

“…Allain et al [9] has reported that the mechanical ε martensitic transformation only occurs if the stacking fault energy (SFE) is lower than 18 mJ/m 2 , that mechanical twinning occurs at SFE roughly in the range 12-35 mJ/m 2 [10], and glide of dislocation would occur when SFE exceeds 45 mJ/m 2 . For 304 austenitic stainless steel under uniaxial tension, two transformation mechanisms were proposed according to the SFE [11][12][13][14]: (a) stress-induced-transformation γ → ε → α (<18 mJ/m 2 ) and (b) strain-induced-transformation, γ → deformation twinning → α (12-35 mJ/m 2 ).…”

Ultrafine-Grained Austenitic Stainless Steels X4CrNi18-12 and X8CrMnNi19-6-3 Produced by Accumulative Roll Bonding

“…Hereby, the growth of α' leads to a reduction of the ε phase. Shen et al [27] found that both ε and twins act as an intermediate phase during the transformation form γ-austenite to α'-martensite. Above a certain strain level, they observed that the twin density is decreasing, while the martensite density is further increasing.…”

Effect of Nitrogen on Deformation-Induced Martensitic Transformation in an Austenitic 301 Stainless Steels

“…Generally, the M d temperature strongly depends on chemical compositions, strain rate, and loading temperature. DIMT in austenitic stainless steels has been observed to proceed either directly from γ-austenite to α' martensite (γ → α') [1,2] or via ε martensite (γ → ε → α') depending on alloy composition and crystallographic orientation [2][3][4][5]. Generally, DIMT phenomenon has been analyzed in terms of either transformation kinetics or stress-strain response [4,[6][7][8][9][10][11][12][13][14][15][16][17].…”

“…Nitrogen provides beneficial effects as an alloying element on the properties, such as superior combination of high yield strength and high elongation, high fatigue life and wear resistance, high resistance to localized corrosion in 300 grade stainless steels [22]. Numbers of researcher have carried on the extensive studied on the relationship between DIMT and chemical compositions, suggesting their own kinetics equations for describing DIMT [1][2][3][4][5][6][7][8][9]. Although considerable knowledge base is available for austenitic stainless steel in general, the understanding developed for 301 stainless steel system with nitrogen effect is still lack [1,23].…”