“…They observed a rather smooth surface with a smaller penetration rate at grain boundaries and thus considerable improvement in intergranular corrosion. For SPD materials, corrosion behavior such as general [10][11][12][13][14][15][16][17][18][19][20], intergranular [21][22][23] and pitting corrosion [21,[24][25][26][27][28][29][30][31][32] of UFG aluminum and aluminum alloy [17,21,22,24,25,[29][30][31][32], copper and copper alloy [11,15,19,28] as well as stainless steels [10,12,18,23,27] and magnesium [13,14,16,20] processed by SPD, and corrosive environment dependence [33][34]…”