Corrosion and microstructure of the metal silicide (Mo1−xNbx)5Si3

► Corrosion and mechanical properties of (Mo1−xNbx)5Si3 alloys were studied. ► The alloys exhibited good corrosion resistance in HCl solutions. ► The secondary passivation behavior of alloy shows higher capacity for repassivation. ► Corrosion behavior of alloys are controlled by the properties of surface passive film. ► Chemical stability and strong bonds to alloys are beneficial to corrosion resistance.