After soaking in the artificial sweat solution for a week,
the surface corrosion topography of each sample was examined
by SEM, as shown in Fig.1.
It can be seen that 1# and 3# include more corrosion pits
or locally corroded areas, moreover, the surfaces become
relatively darker. 2# includes relatively a little less pits,
while 4# and 5# alloy have much less corrosion pits.