Influence of Prior Carbide or Ferrite Precipitation upon Incubation Period for Bainitic Transformation

Experimental Evidence for Non-Cubic Bainitic Ferrite

The first evidence is provided for the existence of a tetragonal or slightly orthorhombic unit cell of bainitic ferrite. It supports the hypothesis that the excess carbon that persists in the ferrite, which is in contact with austenite, is a consequence of an increased solubility due to the change in symmetry from the conventional cubic unit cell. The deviations from the cubic cell are maintain...

Exploring Carbide-Free Bainitic Structures for Hot Dip Galvanizing Products

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...

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...

Critical assessment 20: On carbon excess in bainitic ferrite

For several decades, the question of carbon supersaturation in bainitic ferrite has attracted the attention of physical metallurgists. Originally, this was associated with excess carbon due to the displacive nature ofphase transformation and its subsequent trappingatdefects inbainitic ferrite. The development of advanced experimental techniques, such as atom probe tomography and in situ synchro...