Influence of crystallographic texture and grain size on the corrosion behaviour of as-extruded Mg alloy AZ31 sheets

The influences of crystallographic texture and grain size on corrosion behaviour were investigated using the Mg alloy AZ31 sheets produced in the following ways: as-extruded (AR), cross rolling (CR) and unidirectional rolling (UR). The corrosion rate was measured for immersion of the AZ31 sheets in 3.5 wt.% NaCl solution using hydrogen evolution, potentiodynamic polarisation curves, and mass loss. The corrosion rate of the AZ31 sheets decreased in the following order: AR, CR, UR. The decrease in corrosion rate was attributed to an increase in basal plane intensity in the crystallographic texture and the reduced grain size.