Electrochemical corrosion behavior of carbon steel pipes coated with a protective ceramic layer using plasma and HVOF thermal spray techniques for oil and gas

Ceramic composite Cr3C2–25%NiCr with high corrosion resistivity (up to 900 °C) is applied on carbon steel (SC45) pipes by two different thermal spray-coating techniques: HVOF and Plasma. These techniques can create dense and homogenously deposited layers without affecting the materials’ properties. The corrosion behavior of coated samples is investigated in crude oil solution at 60 °C and 3.5% NaCl solution at 30 °C for 30 days. Potentiodynamic polarization and EIS results show that the HVOF-coated samples exhibit better corrosion resistance than the plasma-coated samples. However, both coating techniques protect carbon steel from a corrosive environment. XRD and FESEM of the coated samples demonstrate that the solution could not reach the substrate.