The effects of boron segregation and austenite grain size on the bainitic isothermal transformation a high-strength steel were studied independently. Dilatometry, microstructural observations previous atom probe tomography analyses showed that rate decreases with increasing excess at boundaries. We also found causes an unexpected effect: large grains transform faster than small ones. A kinetic ...

The selection of crystallographic variants in bainitic microstructures is a deeply studied topic which can be attributed to several reasons. In the cases where prior austenite textured, stressed or plastically deformed, final ferrite texture and dilatometry signal may change, being anisotropic. Although causality between variant variation dilatometric has been previously assumed, it not thoroug...

Bainitic microstructures in which fine platelets offerrite are intimately mixed with films of austenite are known to exhibit good combinations of strength and toughness. It isfound that the thickness of these austenitefilms can be estimated by assuming that the carbon diffusion field around an existing plate offerrite prevents the close approach of another parallel plate. This is because the re...

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 ...

Ausforming treatments at different temperatures were applied to a medium CSi rich carbide free bainitic steel, and the role of transformation plasticity on evolution microstructure is discussed. Three ausforming selected prior isothermal bainite 325 °C. Deformation was above start temperature, BS, (600 °C), below BS (400 temperature (325 °C). A combination high-resolution dilatometry, XRD, SEM,...

In the paper fundamentals of steel parts quench process in liquid media are considered which used for designing new technologies such as intensive quenching that results obtaining fine and nano – bainitic microstructure. These include French law transient nucleate boiling establishing during media, duration, when film is absent, self regulated thermal process. Based on listed fundamentals, vers...

The effect of Si addition on the evolution bainitic transformation, carbon diffusion, carbide formation, and dislocation density in steel was investigated using in-situ high-energy X-ray diffraction (HEXRD). Alloys Fe-0.4C-1.7Mn (in wt%) with 1–4 wt% were austenitized at 1273 K then isothermally heat treated 573, 623, 673 K. According to HEXRD results, increasing content reduces transformation ...