A more effective method of corrosion prevention for metal during transport and storage is the use of vapor phase inhibitor (VPI) .In the shipyard, dicyclohexyl ammonium nitrite (DICHAN) is often used for anti-corrosive protection of box-shaped hatch cover and rudder blades of large ships. However, the disadvantage of DICHAN is its toxicity. Thus, its replacement by new environment-friendly inhibitors is necessary. To deal with such situations, a novel VPI of morpholinium oligomer (MPO) has been developed for temporary protection of large ship in HuDong Shipyard of Shanghai. Its vapor corrosion inhibitiol, property was evaluated under simulated operational conditions. Electrochemical potentiodynmaic polarization method was applied to study the effect of MPO on the corrosion inhibition of carbon steel in ASTM stimulated atmospheric corrosion water. The results showed that it was a good vapor corrosion inhibitor for steel. It suppressed the cathodic reaction of steel electrode and depressed passive region current density of anodic process. Fourier transform infrared (FTIR) was used to characterize the adsorption of MPO on steel surface. The different polar groups of MPO had synergistic adsorption effects.
Keywords: vapor phase inhibitor, morpholinium oligomer, inhibition, atmospheric corrosion