Incomplete bainitic transformation during austempering treatment is mainly caused by the supersatu-ration of austenite with carbon. Such supersaturated becomes more stable and further stabi-lization led silicon alloying. Stable does not transform remains in structure as so-called residual austenite. Therefore, carbides, which are desirable a conventional struc-ture, cannot be formed carbide fre...

A high-strength low-carbon construction structural steel was investigated in the laboratory. The various austenite grain sizes were obtained by austenitizing at different temperatures. effect of size on bainite transformation studied dilatometer. results show that microstructure steels mainly includes granular bainite, lath-like and martensite-austenite (M-A). changes from to with increase temp...

Structural steels with very high strength levels are often referred to as ultrahigh-strength steels (UHSS). The usage of UHSS has been extensively studied in aerospace industries and offshore platforms. In this study, medium carbon low alloy steel (AMS6305) was thermomechanicaly treated to obtain an ultra-high strength bainitic steel for aircraft engine compressor disk. A novel themomechanical ...

Abstract This work presents insights into the manganese influence on driving force and bainite transformation kinetics. Three different medium-Mn steels were subjected to theoretical calculations dilatometric study in order determine Mn impact formation. The approach shows that increase of leads a lower fraction formed during isothermal stage. implicates carbon enrichment austenite thermal trea...

Retained austenite is a key feature used to realize the transformation-induced plasticity in bainitic high strength steels. In this study, authors focused on formation of metastable Fe-0.61C-1.9Si-0.98Mn (mass%) during isothermal heating processes using situ neutron diffraction techniques. Quantitative discussion carbon partitioning enabled by applying an phase fraction analysis considering cry...

Three-dimensional microstructures of bainitic ferrites and prior austenite grains (PAGs) were observed in the initial stage upper bainite transformation by using a serial sectioning technique orientation analysis electron back scattering diffraction (EBSD). The formation site was quantitatively evaluated three-dimensional observation. It revealed that mainly form at planes rather than edges gra...

We give an excerpt of recent developments in the experimentally benchmarked modeling of bainite formation in the press hardening process. As the press hardening process poses a heavily multi-parameter dependent modeling challenge, we focus on three main branches which complement each other. We emphasise the combination of basic sharp interface and phase field models with pragmatically adapted m...

Deformation-induced martensitic transformation (DIMT) during tensile or compressive deformations of the bainitic steels with various carbon content (0.15 %C, 0.25 0.62 %C) was studied. The initial microstructure before deformation tests prepared by austempering at 400 °C to obtain structure consisting ferrite and retained austenite. volume fraction austenite larger in steel content. In all stee...