Cailiao Baohu (May 2023)

Effect of Ce Content on Microstructure and Corrosion Resistance of X100 Pipeline Steel

  • LIU Peng, YANG Ji-chun, LI An-xin, LIU Xiang-jun, YANG Chang-qiao, GONG Lei

DOI
https://doi.org/10.16577/j.issn.1001-1560.2023.0113
Journal volume & issue
Vol. 56, no. 5
pp. 106 – 112

Abstract

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For studying the effect of rare earth element Ce on the microstructure and corrosion resistance of X100 pipeline steel, the four kinds of experimental steels with different Ce contents (mass fractions of Ce were 0,0.001 7%,0.002 8%, and 0.004 9%, respectively) was tested by using a Zeiss microscope, field emission electron microscope with accompanying energy spectrometer and electrochemical workstation. Results showed that as the Ce content increased, the grain size on the surface of the test steel decreased, and Al2O3 inclusions were modified to CeAlO3 and Ce2O3 inclusions. After 7 d of immersion, the corrosion potential of the four test steels was relatively close. After 30 d of immersion, the corrosion potential of the No.3 test steel increased by 8.94% compared to before, while the No.2 and No.1 test steels increased by 6.34% and 6.06%, respectively. After immersing for 45 d, the corrosion potential of No.1 test steel decreased by 10.38% compared to the situation at 7 d, while the corrosion potential of the other three test steels exhibited little change. In addition, the capacitance arc radius of No.0 test steel gradually decreased with the prolongation of immersion time, and the increase in the capacitance arc radius of No.3 test steel was the most significant. The above results all indicated that the increase of the Ce content would improve the corrosion resistance of the test steel.

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