Some oil and gas production systems have critical components internally clad with corrosion resistant
alloys for protecting against specific degradation mechanisms. Experimental and modeling studies have
shown that uninhibited corrosion rates of carbon steel piping could nearly double in areas close to the
CS-Alloy 625 interface. In this work, polarization, galvanic current and immersion tests were
conducted to evaluate the effectiveness of inhibitors to mitigate galvanic corrosion and preferential weld
corrosion of carbon steel coupled to Alloy 625 in CO2-saturated brine at 66 °C. Three inhibitors were
evaluated for their ability to reduce galvanic corrosion at concentration of 150 ppm v/v. All of the
inhibitors evaluated were shown to be efficient in mitigating uncoupled uniform corrosion, but only one
was able to also reduce galvanic currents to negligible values while showing no evidence of preferential
weld corrosion or pitting.
Keywords: Galvanic Corrosion, CO2 Corrosion, Inhibitor, Alloy 625