This paper aims at the phase identification and quantification in transformation induced plasticity duplex stainless steel (TDSS) base and weld metal containing ferrite, austenite, and martensite. Light optical microscopy (LOM) and electron backscatter diffraction (EBSD) analysis were employed to analyze phases. Samples were either mechanically or ...
In this paper, the high temperature transformation kinetics of delta ferrite to austenite (δ → γ) phase transformation is modeled by thermodynamic and diffusion calculations. It appears that, in martensitic steels, the δ → γ transformation is very fast (a few nanoseconds) as soon as the first austenite nuclei appears. Classically the austenitic pha...
The influence of the heating rates from 10 to 1000 degrees C/s and annealing temperatures on the microstructure and mechanical properties of two 0.2%C, 1.9%Mn, 1.4%Si cold-rolled steels with and without the addition of carbide-forming elements (Mo, Nb, and Ti) have been investigated. Results show that the increase of the heating rate above 100 degr...
Due to its hardness, martensite, perhaps, is the most desirable structure, but at the same time, martensite is very brittle. Balancing between hardness and brittleness is a challenge that steel manufacturers must deal with it. To decrease brittleness and to solve this problem, designers purposely temper the steel. Heat treatment, e.g., slowing down...
Les aciers trempants au bore sont définis par une importante trempabilité. Cet effet est lié à la ségrégation intergranulaire du bore dans l’austénite. Dans ces aciers, deux mécanismes de ségrégations du bore coexistent généralement : la ségrégation à l’équilibre et la ségrégation hors-équilibre. Ils ont une force motrice et une cinétique différent...
Published in International Journal of Materials Research
Sub-zero processing is an effective method to enhance the mechanical properties of steel due to the complete removal of residual austenite, and better precipitation of secondary carbides. Especially, the sub-zero processing temperature significantly influences the mechanical properties of steel. In the present study, the impacts of shallow and deep...
Published in Journal of Nondestructive Evaluation
Sliding friction causes significant structural transformations in the subsurface layers of interacting materials. These changes are associated with complicated mechanochemical processes which include but not limited to plastic flow, refinement of structure, increase of dislocation density, oxidation, delamination and formation of wear debris. In th...
International audience
Published in SN Applied Sciences
The objective of the present work is to investigate the mechanical properties of the dual phase (DP) steels produced by the intermediate quenching (IQ) technique. To produce the ferrite-martensite microstructure in the dual phase (DP) steel, low carbon micro alloyed steel is intercritically heat treated followed by short intercritical annealing and...
