【摘 要】
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Strengthen-mechanism and corrosion resistance of niobium addition high strength low alloy weathering H-beams produced by ultra-fast cooling technology,had b
【机 构】
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University of Science and Technology Beijing,Xueyuan Road 30,Haidian District,Beijing,100083,China
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Strengthen-mechanism and corrosion resistance of niobium addition high strength low alloy weathering H-beams produced by ultra-fast cooling technology,had been investigated in this research.The results show that the microstructure of the ultra-fast cooling weathering H-beams sample was consisted of polygonal ferrite and pearlite as well as fine,dispersive and uniform Nb(C,N)precipitates.Niobium element plays its role of grain refinement and precipitation strengthening by refining ferrite grains and obtaining(Nb,Ti)(C,N)precipitation,which significantly improved the strength and toughness.Furthermore,the corrosion resistance performance of weathering H-beams was also studied by simulated atmosphere-salt spray test.It was found that the corrosion rate and thickness reduction of the weathering H-beams with homogeneous rust layer were lower than that of conventional carbon steel Q345.The results also revealed that the corrosion process can be divided into initial stage in which corrosion rate increased with accumulation of corrosion products and the second stage in which homogenous,adherent and compact rust layer started to protect the steel substrate out of corrosion solution.
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