Analysis of work hardening mechanisms in Quenching and Partitioning steels combining experiments with a 3D micro-mechanical model

Quenching & Partitioning (Q&P) steels owe their good strength-ductility combinations to the martensite/austenite (α’/γ) mechanical interactions and to the formation of mechanically-induced martensite (α′_mech) through the transformation-induced plasticity (TRIP) effect. An essential role is played by carbon, whose...

The role of the austenite grain size in the martensitic transformation in low carbon steels

There is sufficient experimental evidence to propose that the formation kinetics of athermal martensite directly depends on the austenite grain structure from which the martensite forms. Yet, this dependence is frequently ignored. The present study investigates the role of the prior austenite grain size (PAGS) in the martensitic...

The influence of the austenite grain size on the microstructural development during quenching and partitioning processing of a low-carbon steel

The influence of the prior austenite grain size (PAGS), varying between 6 and 185 μm, on the microstructural development of a low carbon steel during quenching and partitioning (Q&P) processing is investigated. The effect on the size and morphological aspects of the microconstituents is discussed based on the kinetics of carbon...

In situ study on fracture behaviour of white etching layers formed on rails

Failure in engineering materials like steels is strongly affected by in-service deleterious alterations in their microstructure. White Etching Layers (WELs) are an example of such in-service alterations in the pearlitic microstructure at the rail surface. Cracks initiate in the rails due to delamination and fracture of these layers and...

The role of silicon in carbon partitioning processes in martensite/austenite microstructures

Understanding carbon redistribution in steels is crucial in developing advanced high strength steels. For instance, Quenching & Partitioning (Q&P) processes rely on the partitioning of carbon from martensite into austenite, where at the end of the heat treatment the carbon-enriched austenite shows higher stability at room temperature....

Characterization of bainitic/martensitic structures formed in isothermal treatments below the M_s temperature

Advanced Multiphase High Strength Steels are generally obtained by applying isothermal treatments around the martensite start temperature (M_s). Previous investigations have shown that bainitic ferrite can form from austenite in isothermal treatments below M_s, where its formation kinetics is accelerated by the presence of...