Wet CO2 Corrosion

Carbon dioxide gas (CO₂), when dissolved in water, forms carbonic acid (H₂CO₃). This acid may attack metallic equipment, in particular carbon steels and low-alloy steels. Stainless steels are usually immune to wet CO₂ corrosion. Wet CO₂ corrosion can be relatively uniform (i.e., general corrosion), but more often occurs in the form of pitting, grooving, or the so-called "mesa attack" (protected, scale-covered area co-exists with corroded areas of fresh metal).