REAL-TIME MONITORING OF LOCALIZED AND GENERAL CORROSION RATES IN SIMULATED MARINE ENVIRONMENTS USING COUPLED MULTIELECTRODE ARRAY SENSORS

摘要

Real-time coupled multielectrode array sensor probes were used to measure the maximum localized corrosion rate of Type 1008 carbon steel; Types 1100 and 3003 aluminum; Type 110 copper; and Types 316L, 304L, 904L, and 254 SMO stainless steels in simulated seawater. The real-time general corrosion rates and general corrosion penetration depth for selected alloys were also given, based on the average anodic currents and average anodic charge from the coupled multielectrode array sensor probes. Detailed analyses, for deriving the general corrosion penetration rate and general corrosion penetration depth using the average anodic currents and average anodic charges, were described. Localized corrosion penetration rate factor and localized corrosion penetration depth factor were also discussed. The maximum localized penetration rates for the stainless steels tested were between 0.5 μm/yr (0.02 mil/yr) and 10 μm/yr (0.4 mil/yr). The maximum localized penetration rate for copper 110 was between 8 μm/yr (0.32 mil/yr) to 90 μm/yr (3.5 mil/yr). The maximum localized penetration rate for aluminum 1100 and 3003 was between 70 μm/yr (2.8 mil/yr) and 1000 μm/yr (40 mil/yr). The maximum localized penetration rate for carbon steel 1008 (mainly pitting corrosion) was between 800 μm/yr (32 mil/yr) and 4000 μm/yr (157 mil/yr).