Recent studies on TRIP-assisted multiphase steels have emphasised the drastic importance of the bainitic transformation in the optimisation of properties. Bainitic ageing is necessary for the stabilisation of austenite with respect to the martensitic transformation. This metastable retained austenite can still transform to martensite when plastically deformed (TRIP effect). The present work dea...

The redistribution of carbon after tempering of a novel nanocrystalline bainitic steel consisting of a mixture of supersaturated ferrite and retained austenite has been analyzed by atom probe tomography. No direct evidence supporting the additional carbon enrichment of austenite beyond that initially achieved during the bainite heat treatment was obtained during subsequent tempering of this hig...

this study was conducted in order to investigate the influence of plastic deformation on the transformation of retained austenite in a trip steel with a high content of al and a low content of si. to the aim, appropriate treatments were used to produce the starting material (trip steel). the microstructure of the obtained steel was composed of bainite and phases including ferrite and retained a...

Terms of service of the steels with retained austenite in the microstructure, is severely depended on the stability of austenite during the course of deformation. The present work aims to evaluate the mechanical stability of austenite in nanostructured, carbide free bainitic steels during tensile testing and cold rolling process. To achieve the microstructure with retained austenite, the steel ...

transformation induced plasticity (trip) steels have a vast application in automotive industry because of theirhigh strength, high ductility and hence excellent energy absorption capacity. these characteristics of tripsteels are due to the existence of retained austenite in their microstructures in the ambient temperature, whichtransforms to the martensite phase during deformation. the microstr...

High resolution synchrotron X–ray diffraction has been used to conduct in situ studies of the temporal evolution of phases during the isothermal growth of bainite. Two populations of austenitic material were identified: one corresponding to the initial austenite, the other to the carbon–enriched austenite associated with the bainitic ferrite. The observed lattice parameters and the asymmetry of...

The uniaxial thermomechanical behavior of a polycrystalline Fe-9%Cr-5%Ni-14%Mn-6%Si (all wt.%) shape memory alloy is investigated for both tensile and compressive stress states. The martensite start stresses measured upon tension and compression loading of austenite depend linearly on temperature, thus forming straight lines in the stress-temperature regime. The lines belonging to tension and c...

Austenite formation and its decomposition control the final microstructure and performance of steel welds. This paper presents an in-situ characterization of austenite formation and its decomposition in both the fusion zone (FZ) and heat-affected zone (HAZ) of an Fe-C-Al-Mn steel using time-resolved X-ray diffraction (TRXRD) with synchrotron radiation. Measurement of X-ray diffraction spectra a...

Deformation and work hardening behavior of Fe-17Mn-0.02C steel containing ε-martensite within the austenite matrix have been investigated by means of in situ microstructural observations and x-ray diffraction analysis. During deformation, the steel shows the deformation-induced transformation of austenite → ε-martensite → α'-martensite as well as the direct transformation of austenite → α'-mart...

The goal of this paper is to analyse the effect of adding Al on the non-steady pearlite growth occurring in a Fe-C-Mn system. The results are discussed in terms of the partitioning of elements across the austenite/ferrite and austenite/cementite interfaces, and the modification of the pearlite driving force related to the change in carbon activity in austenite.