Corrosion Behavior of P110S Oil Pipe in Simulated Working Condition

Abstract

The corrosion resistance of P110S steel in CO2 and H2S coexistence corrosion environment under different temperature and PCO2/PH2S was investigated by high temperature and high pressure (HTHP) reaction kettle combined with SEM, EDS and XRD analysis methods. The stress corrosion cracking (SCC) resistance of P110S steel was studied under loading pressure of 682.2MPa (758MPa×90%) in simulated conditions after 720 hours test. The results show that the P110S steel has serious corrosion in the range of simulative temperature and H2S partial pressure. With the increase of temperature, the corrosion rate decreases first and then increases. With the increase of H2S partial pressure, the corrosion rate increases first and then decreases. The P110S steel has the highest corrosion rate when the temperature is 50 °C and H2S partial pressure is 0.1%. After the anti-SCC test, the specimens did not fracture, and cracks perpendicular to the tensile stress were not found on the surface. That is, P110S has good SCC resistance in the corrosive environment.