Characterization of the corrosion behavior of different stainless steelalloys exposed to flowing fresh seawater, using E.I.S technique

摘要

E.I.S technique was used to characterize the corrosion behavior of UNS NO. S 31600rnstainless steel, UNS NO. S 30400 stainless steel and UNS NO. S 62800 sanicro 28 exposed torncontinuous fresh Seawater. The total exposure time of the test was about 180 days. Two typesrnof additives (4 ppm of Cl2 and 5 ppm of NH3) were also added to the seawater to investigaterntheir effect on the surfaces of these alloys. During the tests, no marine - macro fouling wasrnobserved on the surfaces of the tested alloys, as the seawater was filtrated at the DoharnDesalination Research Center, where the study was carried out, but only a slimy layer spreadrnon the whole surface of the alloys. The corrosion behavior of each alloy was monitored by thernopen circuit potential measurement, and the E.I.S technique using the EG&G 352 softwarernand hardware instrument, where the resistance of the solution (Rsol), the resistance of thernsurface of the tested alloy (Rp), and the double layer capacitance (Cdl) was calculated. Underrnthis study's experimental conditions, results indicated that the stainless steel alloys werernhighly resistant to marine fouling and corrosion in seawater, and were not affected by thernaggressive additives, such as NH3, and Cl2 in the seawater.