Corrosion behavior of low-carbon Cr micro-alloyed steel for grounding grids in simulated acidic soil
Jian Li1 . Hang Su1 . Feng Chai1 . Dong-mei Xue1 . Li Li1 . Xiang-yang Li2 . Hui-min Meng3
1 Division of Engineering Steel, Central Iron and Steel Research Institute, Beijing 100081, China 2 Enterprise Management Department, China Iron and Steel Research Institute Group, Beijing 100081, China 3 Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China
Corrosion behavior of low-carbon Cr micro-alloyed steel for grounding grids in simulated acidic soil
Jian Li1 . Hang Su1 . Feng Chai1 . Dong-mei Xue1 . Li Li1 . Xiang-yang Li2 . Hui-min Meng3
1 Division of Engineering Steel, Central Iron and Steel Research Institute, Beijing 100081, China 2 Enterprise Management Department, China Iron and Steel Research Institute Group, Beijing 100081, China 3 Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China
摘要 To improve the corrosion resistance of steels for grounding grids, a low-carbon Cr micro-alloyed steel was developed (C1 steel), and corrosion behavior of Q235 steel and newly developed C1 steel in simulated acidic soil was investigated. The corrosion rate was evaluated with the mass loss measurements, while the corrosion morphology of surface and cross section of rust layer was observed by scanning electron microscopy. The corrosion products were analyzed by energy-dispersive X-ray spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy, and the polarization curve was measured using potentiodynamic polarization method. Results indicated that C1 steel displayed good corrosion resistance in the simulated acidic soil, of which the corrosion rate was only 30% of that of Q235 steel after corrosion for 360 h. The analysis of rust layer showed that lower carbon content in steel could reduce the tendency of micro cell corrosion and appropriate amount of chromium could improve the corrosion potential of metal matrix. Moreover, the analysis of X-ray photoelectron spectroscopy revealed that the chromium enriched in inner rust layer of C1 steel existed mainly in the form of Fe2CrO4, which facilitated the formation of Cr-goethite and improved the protection of corrosion products.
Abstract：To improve the corrosion resistance of steels for grounding grids, a low-carbon Cr micro-alloyed steel was developed (C1 steel), and corrosion behavior of Q235 steel and newly developed C1 steel in simulated acidic soil was investigated. The corrosion rate was evaluated with the mass loss measurements, while the corrosion morphology of surface and cross section of rust layer was observed by scanning electron microscopy. The corrosion products were analyzed by energy-dispersive X-ray spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy, and the polarization curve was measured using potentiodynamic polarization method. Results indicated that C1 steel displayed good corrosion resistance in the simulated acidic soil, of which the corrosion rate was only 30% of that of Q235 steel after corrosion for 360 h. The analysis of rust layer showed that lower carbon content in steel could reduce the tendency of micro cell corrosion and appropriate amount of chromium could improve the corrosion potential of metal matrix. Moreover, the analysis of X-ray photoelectron spectroscopy revealed that the chromium enriched in inner rust layer of C1 steel existed mainly in the form of Fe2CrO4, which facilitated the formation of Cr-goethite and improved the protection of corrosion products.
LI Jian,SU Hang,CI Feng, et al. Corrosion behavior of low-carbon Cr micro-alloyed steel for grounding grids in simulated acidic soil[J]. Journal of Iron and Steel Research International, 2018, 25(7): 755-765.
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2018, Vol. 25 
