Research on the Corrosion Behavior of Mo/C276 Coating Deposited by HVOF Method in Deep-Sea Cold Seep Environments

In this study, the Mo/C276 coating was deposited on Q690E steel by high velocity oxy-fuel spraying (HVOF), and the coating was treated with an organosilicon sealer. Further, the corrosion behaviors of the coating in the simulated deep-sea cold spring environment with hydrogen sulfide and high pressure were studied. The results show that when the oxygen flow rate is 220 NL/min, the coating has the lowest porosity of 1.71% and excellent mechanical properties. Combined with the micromorphology and elemental analysis of the coating, it was assumed that the Fe element generated by the corrosion of the Q690E substrate migrates to the surface of the coating. The corrosion tests in the simulated deep-sea cold showed that before the failure of the coating in the edge and corner areas, the corrosion rate of the coating was less than 0.002 mm/a, which could meet the long-term use requirements in the real cold spring environment.