Phase instabilities in austenitic steels during particle bombardment at high and low dose rates

•Ballistic dissolution of different nanocluster species similarly irradiated can vary.•Neutron irradiation forms Cu-rich clusters in 304L but ion irradiation dissolves them.•Neutron irradiation-induced Ni-Si-Mn-rich clusters are stable/grow by ion irradiation.•A modified Heinig model validated the critical conditions for nanocluster stability.•RED and near-interface solute gradients control recovery from ballistic dissolution.