The effects of inclusions on localized corrosion of Zr–Ti deoxidized low-alloy steels in marine environment were investigated by various analytical techniques including scanning electron microscopy with X-ray microan...The effects of inclusions on localized corrosion of Zr–Ti deoxidized low-alloy steels in marine environment were investigated by various analytical techniques including scanning electron microscopy with X-ray microanalysis(SEM/EDS),confocal Raman microscopy(CRM),and in situ scanning vibrating electrode technique(SVET).It was found that complex(Zr,Ti,Al)-O_(x)inclusions were responsible for the initiation of localized corrosion.Localized corrosion pref-erentially occurred at Fe matrix adjacent to these inclusions and formed micro-gaps.In the early stage of corrosion,catalytic-occluded cells and the diffusion of chloride ions played a major role in the propagation of corrosion,further accelerating the dissolution of Fe matrix and(Zr,Ti,Al)-O_(x)inclusions.Combining SVET and CRM results,it revealed that the maximum anodic current density in local area gradually decreased with prolonged exposure time,indicating that corrosion products covered the steel surface and lowered the propagation rate of corrosion.In the later stage of corrosion,the barrier effect of corrosion products played an important role in inhibiting localized corrosion.展开更多
基金The financial support from the National Natural Science Foundation of China(Nos.51601138 and 51601137)and the State Key Laboratory of Refractories and Metallurgy(No.2018QN18)is highly acknowledged.The authors are also grateful to the support from the 973 Program(No.2014CB643300)+1 种基金the 111 Project(No.D18018)Excellent Young and Middle-aged Science and Technology Innovation Team in Colleges and Universities of Hubei Province(No.T201903).
文摘The effects of inclusions on localized corrosion of Zr–Ti deoxidized low-alloy steels in marine environment were investigated by various analytical techniques including scanning electron microscopy with X-ray microanalysis(SEM/EDS),confocal Raman microscopy(CRM),and in situ scanning vibrating electrode technique(SVET).It was found that complex(Zr,Ti,Al)-O_(x)inclusions were responsible for the initiation of localized corrosion.Localized corrosion pref-erentially occurred at Fe matrix adjacent to these inclusions and formed micro-gaps.In the early stage of corrosion,catalytic-occluded cells and the diffusion of chloride ions played a major role in the propagation of corrosion,further accelerating the dissolution of Fe matrix and(Zr,Ti,Al)-O_(x)inclusions.Combining SVET and CRM results,it revealed that the maximum anodic current density in local area gradually decreased with prolonged exposure time,indicating that corrosion products covered the steel surface and lowered the propagation rate of corrosion.In the later stage of corrosion,the barrier effect of corrosion products played an important role in inhibiting localized corrosion.
