Influence of Al on internal friction spectrum of Fe–18Mn–0.6C twinning-induced plasticity steel

Temperature dependence of the flow stress of Fe–18Mn–0.6C–xAl twinning-induced plasticity steel

“…The intensity of the three texture components was similar for the three steels. The Néel temperatures were 287, 273 and 266 K for the 0Al, 1.5Al and 2.5Al TWIP steel, respectively [21].…”

“…In the case of Fe-Mn-C austenitic alloys, the temperature-dependent shear modulus has not been yet reported. In previous work, the modulus anomaly due to the spontaneous volume magnetostriction during the paramagnetic to antiferromagnetic transition below the Néel temperature was reported to occur at $273 K (0°C) in 0Al, 1.5Al and 2.5Al TWIP steel [21]. The modulus anomaly occurs only for elastic constants that have a dilatational component, such as the bulk modulus, Young's modulus and Poisson's ratio, but no anomaly should occur for the shear modulus [26].…”

“…The experimental strain hardening for a FeMnC-Al TWIP steel with 1.5% Al deformed at 293 K is shown for comparison. increased the activation energy for C diffusion in TWIP steels [21].…”

“…The occurrence of DSA at elevated temperatures in C-or Nadded body-centered cubic (bcc) ferrous alloys is well known. The activation energy for interstitial atom diffusion in bcc Fe alloys [34] is much lower than the activation energy for interstitial diffusion or interstitial-substitutional complex reorientation in TWIP steel [21]. The DSA in TWIP steel cannot therefore be explained by the longrange diffusion of interstitial C. Recently, Lee et al [2] suggested that the DSA in TWIP steels may result from the short-range order due to the presence of C-Mn point defect complexes which can reorient themselves in the stacking fault region of dissociated dislocations.…”

“…The effect of Al of DSA appears to be twofold. First, Al delays the reorientation of Mn-C point defect complexes by increasing the activation energy of the process [21]; and second, Al decreases the interaction between the stacking fault and the Mn-C point defect complexes due to the reduced dissociation width [2].…”