Dissolution kinetics of intermetallics in aging austenitic steels during neutron irradiation

The Mössbauer spectroscopy, X-ray diffraction analysis, and the electron transmission microscopy were used to study the dissolution kinetics of dispersed Ni3Ti γ′-precipitates in displacement cascades at 340 and 530 K during neutron irradiation of the aged 35Ni3Ti austenitic steel (Fe+34.2 at.% Ni+3 at.% Ti). The dissolution was significantly intensified as the initial size of the particles decreased. At high neutron fluence and temperature, the dissolution was accompanied by competitive precipitation of the intermetallics. During irradiation at 340 K, the Ni concentration in the austenite matrix tended to some equilibrium value of about 32.2 at.%.