Selection of Materials for Embedded Sacrificial Anode in Heavy Oil Pipeline

The applicability of aluminum alloy and zinc alloy as sacrificial anode materials in high-temperature heavy oil pipelines was studied through corrosion test, constant current accelerated test and coupling performance test. The results show that as the temperature increased, the corrosion rate of the two anode materials increased, the actual capacitance and current efficiency decreased, the consumption rate increased, and the service life decreased. At 80 ℃, the corrosion rate and consumption rate of aluminum anode were lower than those of zinc anode, and the coupling potential with T/S-52K pipeline steel was more negative, the coupling current was larger, and the cathodic protection effect was more significant. Working potential of zinc anode at 80 ℃ was higher than the minimum protection potential, which did not meet the requirements of the GB/T 21448-2017 standard. Aluminum alloy is more suitable than zinc alloy used as sacrificial anode material for high-temperature heavy oil pipelines.