Papers by Author: Yan Han

Abstract: Aimed at the problem of sulfur-resistant corrosion in environment with carbon dioxide(CO2)and trace amounts of hydrogen sulfide (H2S), Tafel polarization curves and electrochemical impedance spectroscopy techniques were employed to study the electrochemistry corrosion behavior of two kinds of 80S(A and B) at different temperatures. The methods of weight-loss，scanning electron microscope and X-ray diffraction (XRD) analysis were used to study on the corrosion behavior of the sulfur-resistant tubes, including electrochemical impedance spectroscopy , average corrosion rates and the corrosion morphologies. The results showed that the corrosion potential and corrosion rates (CR) of two samples were different with the changing of the test temperatures. With the increase of the temperature, the corrosion potential decreased, and the corrosion rates increased, but decreased at 120°C. The corrosion-resistant of A80S was slightly superior to the B80S. The serious pitting corrosion and the maximum average CR occurred at 90°C. The XRD analysis suggested that the main corrosion products were FeS.

Abstract: Today’s global exploration of oil and gas leads to a range of highly corrosive environment that, in turn, require corrosion resistant high nickel content alloys for Oil Country Tubular Goods. Aimed at the problem of oil tube corrosion in environment with high content of H2S and CO2, the corrosion behavior of two nickel based alloys in 15%NaCl solution containing H2S/CO2 in high temperature and high pressure environments were researched. The pitting corrosion behavior of Ni-based alloys were investigated in FeCl3 solution by polarization curve and immersion test. The scanning electron microscopy(SEM), energy disperse spectroscopy(EDS) were applied to analyse the microstructure and corrosion performance of the samples. The results showed that the pitting-resistant of G3 was superior to Incoloy825.With the experimental temperature increasing, the corrosion rates increased and some slight corrosion pits appeared on the surface of Incoloy 825, Its maximum corrosion rate was 0.018mm/a. XRD showed that the corrosion films formed on nickel base alloys were consist of NiS, FeS and the oxides of Ni and Cr. The polarization curves showed that there were different corrosion behavior of two alloys, the anodic curve of G3 has an obvious passivation region, and there has higher pitting potential .