Dataset of a thermal model for the prediction of temperature fields during the creation of austenite/martensite mesostructured materials by localized laser treatments in a Fe-Ni-C alloy

This work presents constitutive equations and a dataset of a thermal model for the prediction of temperature fields and heating rates during the application of localized laser treatments to a Fe-C-Ni alloy. The model considers transient material properties and the coupling between temperature and microstructure, with emphasis on the phase...

Microstructures in a carburized steel after isothermal pearlitic treatment

The influence of carbon concentration variations on pearlite formation (20 h at 600 °C) in a case-carburized steel is investigated. The resultant microstructure shows three distinct regions: carburized case, a transition region, and the original core. The microstructural transition from the case to the core regions is observed to be...

Exploring the effect of complex hierarchic microstructure of quenched and partitioned martensitic stainless steels on their high cycle fatigue behaviour

Recent studies have demonstrated the viability of quenching and partitioning (Q&P) treatment for processing martensitic stainless steels showing an improved balance of high strength and sufficient ductility. However, to date, the fatigue behaviour of these materials has not been explored. This study examines the effect of their complex...

Effect of microstructure on tensile properties of quenched and partitioned martensitic stainless steels

Quenching and partitioning (Q&P) treatment has been proven effective in manufacturing advanced high strength steels with high content of retained austenite, showing the improved balance of high strength and sufficient ductility. This method has been very well elaborated for carbon steel processing over the last two decades. Though it can...

Characterization of a Medium Mn-Ni Steel Q&P Treated by a High Partitioning Temperature Cycle

In this work, a medium Mn-Ni steel was treated through Quenching and Partitioning (Q&P) with a partitioning temperature (PT) of 650 °C, which corresponded to the start of the austenite reverse transformation (ART) phenomenon. The influence of the quenching temperature (QT) and partitioning time (Pt) on austenite stabilization and mechanical...

Influence of chemical segregation on bainitic microstructures in a carburized bearing steel

Bainite to austenite reversal is one of the grain refinement techniques employed in carburized steels. However, chemical segregation influences the homogeneity of the bainitic structure, which is seminal to exploit the advantages associated with austenite reversal. It is therefore important to understand the influence of chemical segregation...

Effect of the anisotropy of martensitic transformation on ferrite deformation in Dual-Phase steels

The volume increase and shape change during austenite to martensite transformation in dual-phase (DP) steels are largely accommodated in the microstructure by the deformation of the surrounding ferrite matrix. Accurate estimation of transformation-induced deformation of ferrite via experiments and modeling is essential for predicting the...

Understanding ferrite deformation caused by austenite to martensite transformation in dual phase steels

During the production of DP steels, the volume expansion and shape change accompanying the austenite to martensite transformation is accommodated by the deformation of surrounding ferrite grains. The extent of the deformation in ferrite grains ultimately affects the mechanical properties of DP steels. Using electron backscatter diffraction...

The Thermal Stability of Quenched and Partitioned Steel Microstructures

The quenching and partitioning (Q&P) process is a heat treatment process, aiming at the creation of steel microstructures composed of martensite and retained austenite. Herein, the thermal stability of the microstructure is investigated upon reheating steel microstructures, created with different Q&P settings, in different thermal...

Unravelling the mechanical behaviour of advanced multiphase steels isothermally obtained below M_s

The initial formation of athermal martensite was proven to accelerate the subsequent bainite formation kinetics during isothermal holdings below the martensite-start temperature (M_s). The presence of prior athermal martensite (PAM) within the phase mixture is expected to modify the overall mechanical response of these newly...

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...

Microstructure evolution during high-temperature partitioning of a Medium-Mn Quenching and Partitioning steel

Medium-Mn Quenching & Partitioning (Q&P) steels have been recently considered as potential candidates for the 3rd generation advanced high-strength steels. The processing of these steels aims to induce the partitioning of substitutional alloying elements from martensite to austenite during an isothermal treatment at high temperature,...

Interplay between metastable phases controls strength and ductility in steels

By means of high-energy synchrotron X-ray diffraction, the interplay between martensite and retained austenite phases in steel during the application of stress has been analyzed. Martensite properties were varied through controlled reheating heat treatments in a low carbon Quenched and Partitioned (Q&P) steel consisting of retained...

Fracture mechanisms and microstructure in a medium Mn quenching and partitioning steel exhibiting macrosegregation

A medium-Mn steel, exhibiting manganese macrosegregation, was investigated. In order to study how the microstructure development influences the fracture mechanisms, the steel was quenching and partitioning processed using two different partitioning temperatures. At 400 °C partitioning temperature, the microstructure exhibits intergranular...

Influence of the prior athermal martensite on the mechanical response of advanced bainitic steel

The accelerated formation of bainite in presence of martensite is opening a new processing window for the steel industry. However, for a feasible industrial implementation, it is necessary to determine the mechanical behaviour of the steels developed under such conditions. This study focuses on analysing the effects of the formation of...

Thermal and mechanical stability of retained austenite surrounded by martensite with different degrees of tempering

The mechanical and thermal stability of austenite in multiphase advanced high strength steels are influenced by the surrounding microstructure. The mechanisms underlying and the relations between thermal and mechanical stability are still dubious due to the difficulty of isolating other factors influencing austenite stability. In this work,...