Papers by Author: Xiao Xue Zhang

Abstract: The effects of the magnetic field intensity on microstructure and crystallographic orientation of proeutectoid ferrite in Fe-0.36C alloy have been investigated. Results show that the amount of the Widmänstatten ferrite decreases with the increase of the magnetic field intensity. The transformed proeutectoid ferrite tends to elongate and align along the field direction due to the magnetic dipolar interaction. This tendency is more pronounced when the field intensity increases. Moreover, the enhancement of the <001> fiber component along the traverse field direction by magnetic field is obvious when the field intensity is stronger.

Abstract: The effects of the 12T magnetic field on transformed morphology and crystallographic characteristics of high purity Fe-1.1C (wt.%) alloy during diffusional decomposition of austenite are studied by SEM/EBSD. With the applied field, the lamellar spacing of pearlite is greatly enlarged and the spheroidization tendency of the pearlitic cementite is enhanced. This can be attributed to the thermodynamic effect of the field on phase equilibrium by elevating the eutectoid temperature; hence the eutectoid transformation happens at higher temperature that favors carbon diffusion. As a consequence, the eutectoid cementite that is usually in lamellar shape spheroidizes to reduce its specific surface area. In addition, three orientation relationships between ferrite and cementite in pearlite, namely Isaichev ORs and two near Pitsch-Petch ORs (P-P1 and P-P2), are found both in non-field and field treated specimens. The magnetic field favors the occurrence of P-P2 OR due to the promotion of nucleation of the pearlitic ferrite. However, there is no obvious effect of the field on the crystallographic orientation of pearlitic ferrite, and that is probably related to the quick saturation of magnetization that results in the disappearance of magnetization anisotropy.