Revealing Prior-Austenite Grain Boundaries

EFFECT OF AUSTENITE GRAIN MORPHOLOGY ON VARIANT SELECTION OF MARTENSITE TRANSFORMED FROM ULTRAFINE-GRAINED AUSTENITE

In this research, variant selection of martensite transformed from ultrafine-grained (UFG) austenite fabricated by accumulative roll bonding (ARB) process and subsequent annealing was investigated with respect tomorphology of parentaustenitic phase. The results show that the original shape of austenite grain is very effective factor in determiningthe preferred variants of martensite transformed...

Research on abnormal grain growth in reversely transformed austenite structure

Avrami theory for transformations from non-uniform austenite grain structures

Classical overall transformation kinetics theory for grain boundary nucleated transformations relies on the assumption that the parent phase grain size is uniform. In the present work the theory is adapted to deal with the case where there is a distribution in the size of the parent grains, as is often found in practice. It is demonstrated that the overall transformation rate is fastest when th...

Stabilization of Austenite Associated with Prior Formation of Martensite

The stabilization of retained austenite was studied via a two-step cooling procedure. Alloys with M , temperatures below 0 OC were used. It was found that the martensitic transformation starting temperature, M,, was lowered to M,' during the second step of cooling. With increasing the amount of previously formed martensite, the difference in the transformation starting temperatures, AM, (= M,M,...

Electrical Properties of Grain Boundaries

The electrical properties of grain boundaries are very different in insulators, semiconductors and metals. We present them briefly in the case of insulators and semiconductors and with more details in the case of metals.