This chapter discusses the alloy system CoPt3. The migration of SIA has been investigated for the fully ordered phase after low temperature ion irradiation by field ion microscopy. The chapter also discusses about CrxFe1-x and ferritic steels. The SRO alloy was considered as model alloy for low swelling ferritic steels. The characteristics of the SRO changes from short range ordering to short range clustering. In spite of these changes no major differences are observed for the isochronal annealing of the electrical resistivity after e--irradiation at 20 K for CrFe. Annealing after neutron irradiation is shown for CrFe. The figure shows that there are only minor changes of the annealing spectra by carbon doping, however, 0.29 at% of Nb seem to suppress the high temperature annealing (i.e. by trapping vacancies). For comparison an austenitic solid solution is shown; the major differences to the ferritic alloys are observed in the region of the change of SRO. Another figure summarizes the results for the major annealing stages for CrFe; there is no dramatic change with alloy composition. Finally, the chapter discusses about CrFeNi solid solution and austenitic steels. The pure ternary solid solution alloy is considered as a model alloy for austenitic stainless steels and has been investigated by resistivity measurements after low temperature electron and neutron irradiation. The influence of different impurities on the defect annealing is shown. The dependence of the effective migration energies of SIA and V on the alloy composition, and the formation energy of V are shown.