Effect of ECAP processing on corrosion resistance of AE21 and AE42 magnesium alloys

► Corrosion resistance in AE21 and AE42 magnesium alloys were studied. ► ECAP processing has a strong effect on corrosion properties and microstructure. ► The ECAP processing resulted in ultra-fine grained structure in AE21 and AE42 alloys. ► The corrosion resistance after ECAP decreased in AE21, contrary increased in AE42. ► The explanation of such inconsistency was suggested.