RN and pit depth measurement yield the supportive
information to each other. Deterioration of stainless
steel surface could be quickly determined by RN.
Weight change can be negative or positive. Weight
changes of the coupons were very small. For the long
exposure period, this might not be the good method
to determine the corrosion resistance because the
edges of the coupons would corrode heavily
comparing to the other area. The surface area 1 cm.
from the edges was disregarded. But the corrosion of
the disregarded area could affect the weight change
of the whole specimen. Roughness and brightness of
the coupons were insignificantly different. Therefore,
these parameters were also not suitable for this
purpose.