材料期刊网

In order to investigate the CO2 corrosion behavior and the grooving corrosion susceptibility of electric resistance welded tubes of the Q125 grade, the high temperature and high pressure autoclave was employed to conduct CO2 corrosion experiments for the welded joint. The mechanisms of grooving corrosion and the factors inlfuencing grooving corrosion susceptibility were identiifed by electrochemical measurement, microstructure observation, residual stress examination, micro-region composition and orientation analysis. The CO2 corrosion results show that the corrosion resistance of the base material is the best, followed by heat-affected zone and the welded seam is the worst. The grooving corrosion occurred in the welded seam, and the grooving corrosion susceptibility of welded seam is relativity high. The dominated reason for the grooving corrosion of the electric resistance welded jointis the notable inclusions consisting of MnS as the main content in the welded seam.The proportion of high-angle grain bound-aries in the welding zone is higher than that of base metal and the heat affected zone, which plays an important role in the corrosion behavior of the welded seam.