Passive alloys, crevice corrosion dissolution current

It is important to know whether or not the alloy is resistant to crevice corrosion. For instance, work on the various grades of steels, such as SS 304, carpenter alloy, Incoloy (Alloy 825), Hastelloy (Alloy g), and Inconel (625) showed that the later two alloys were highly resistant to crevice corrosion in ambient and elevated temperature seawater [6]. The alloying elements in various grade of steel affect both the electrochemical and chemical processes, such as hydrolysis, passive film formation, passive current density and metal dissolution. Hence, the effect of major alloying elements, such as Fe, Cr, Ni and Mo and... 

On titanium alloys, however, the metal still has an active-passive transition in the crevice environment and the surface potential must be low enough for the active corrosion to occur. Thus, IR drop is required to stabilize the active dissolution [9,74], particularly when large cathodic currents are available. 

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