Experimental investigation of the influence of the stress state on the mechanical stability of austenite in multiphase steels

Systematic Characterization of the Crashworthiness Properties of Low Alloys Silicon Bearing TRIP Steels

“…22,24,[27][28][29][52][53][54] Stress state -The influence of the stress state on the transformation kinetics is obvious when comparing the quasistatic tension and compression results. The results are consistent with the experimental observations reported by various authors 7,[31][32][33]53,55,56) indicating that the transformation is favoured with the increase in the stress state level ∑. Therefore the volume fraction of transformed martensite is higher in tension than in compression .…”

“…The stress state effect on the martensitic transformation in low alloy, TRIP assisted, multiphase steel has been investigated by several authors and they reported similar findings. Furnemont et al 31) conducted experiments in pure uniaxial tension, at quasi-static strain rate, on various specimen geometries in order to alter the resultant stress state value. Their experimental results revealed that the increase in stress state promotes the transformation of the retained austenite.…”

Formability Evaluation of TRIP-aided Steel Sheets with Different Microstructures: Polygonal Ferrite and Bainitic Ferrite Matrix

“…It is known that in addition to metallurgical parameters, stability of retained austenite in a TRIP-aided steel sheet also depends on stress triaxiality. The stability decreases with increasing the stress triaxiality of the process [14]. Stretch forming exhibits high value of stress triaxiality (2/3 in biaxial stretching), hence in order to avoid early martensitic transformation, retained austenite phases should possess high values of stability.…”

“…This inconsistency is contributed from different matrix microstructure in BF and PF samples which leads to different strain hardening mechanisms. Also different stress state in uniaxial tensile test and stretch forming mode [13], which in turn affects the stability of retained austenite [14], has great effects on the amount of strain induced martensitic transformation and consequently on the properties of TRIP steel. Above mentioned reasons suggest that formability should be evaluated based on formability tests and cannot be predicted by tensile test.…”

Numerical modeling of advanced materials

“…Also, since expansion is isotropic and of the same amount for all the martensitic variants, this work is constant, which leads to the conclusion that the effect of hydrostatic stress is a linear increase in the mechanical driving force. There are multiaxial experiments carried out to quantify this phenomenon as in [11,37,38].…”