On the segregation redistribution in the Fe-Ni austenite under thermal and radiation effects

The possibility that two types of phase transformations - the radiation-induced and thermally activated decomposition of austenite to nickel-enriched and nickel-depleted FCC components - take place in the previously thought of as the single-phase high-temperature (773-973 K) range of the Fe-Ni equilibrium diagram was analyzed. The Moessbauer and electron microscopic investigations showed that the purposefully produced concentration-inhomogeneous FCC alloys of iron with 32-34% Ni were fully homogenized in that high-temperature region. This fact indicates to the absence of the thermal decomposition dome in the said areas of the Fe-Ni equilibrium diagram. (orig.)