Synchrotron X-ray studies of austenite and bainitic ferrite

Synchrotron X–ray Studies of Austenite and Bainitic Ferrite

High resolution synchrotron X–ray diffraction has been used to conduct in situ studies of the temporal evolution of phases during the isothermal growth of bainite. Two populations of austenitic material were identified: one corresponding to the initial austenite, the other to the carbon–enriched austenite associated with the bainitic ferrite. The observed lattice parameters and the asymmetry of...

Tempering of hard mixture of bainitic ferrite and austenite

Recent work has shown that bainitic ferrite plates produced by transformation at low temperatures can be as thin as 20 nm with a hardness in excess of 650 HV30, tensile strengthy2.3 GPa and toughnessy30 MPa m. Because these properties rely on the fine scale of the microstructure, a study has been carried out in relation to the tempering resistance of steel over the temperature range 350 – 750uC...

Austenite films in bainitic microstructures

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...

Synchrotron X-Ray Studies of Surface Disordering Semiconductor Surface Studies

The effect of aluminium and phosphorus on the stability of individual austenite grains in TRIP steels

We have performed in situ synchrotron X-ray diffraction experiments to assess the influence of aluminium and phosphorus on the austenite stability in low-alloyed transformation-induced plasticity steels during the high-temperature bainitic holding and the subsequent martensitic transformation during cooling to temperatures between room temperature and 100 K. Although the addition of aluminium i...