Martensitic and bainitic steels are two types of widely used steels with excellent mechanical behaviors in automatic industry. It’s universally acknowledged that asquenched martensite possesses poor ductility and impact toughness, which should be tempered before putting into application. During tempering, as-quenched martensite changes from a hard and brittle microstructure to more ductile and ...

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 paper reports on the precipitation behaviour and microstructural evolution in ~20% cold rolled NbMoV and V single microalloyed low carbon steels during intercritical annealing. The microstructure and precipitation behaviour were studied by optical and scanning/transmission electron microscopy and microanalysis, X-ray diffraction technique and Vickers hardness testing. After intercritical a...

Microscopic stress and strain partitioning control the mechanical damage behavior of multiphase steels. Using a combined numerical experimental approach, local distributions deformation localization are characterized in carbide free bainitic steel produced by continuous cooling. The microstructure consists bainite (aggregate ferrite thin film retained austenite), martensite blocky austenite. Nu...

The development of nano/ultrafine bainitic structure in AISI 52100 steel was the goal of this study. For this purpose,the AISI 52100 the specimens were austenitized at 1050 °C for 60 min followed by low-temperature austemperingtreatment at different temperatures and times. The austempered samples were characterized using field emissionscanning electron microscopy (FESEM), X-ra...

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...