<p>A periodic layered structure consisting of alternating Cr-Al-B MAB phase and FeAl₃ was generated during hot-dip aluminizing of Fe-Cr-B cast steel. Unlike for the MAX phase, reports on the interaction of MAB phase with molten salt are rare. So far, no Ag whiskers have grown on the MAX/MAB phases. In this study, the interaction between this periodic layered structure coating and molten AgCl salt at different temperatures was investigated. Results demonstrated that the Ag⁺ in the molten salt could react with the periodic layered structure coating, leading to its whitening. Specifically, Ag⁺ preferentially reacted with the Cr-Al-B MAB phase and resulted in the generation of Cr-(Al, Ag)-B MAB phase solid solution through partial replacement of Al atoms at the A-sites in the Cr-Al-B MAB phase; interaction of Ag⁺ with FeAl₃ resulted in the formation of Ag₃Al through an intermediate product of Fe-Al-Ag intermetallic compound. Ag whiskers spontaneously grew on the whitened Cr-(Al, Ag)-B MAB phase solid solution for the first time.</p>