Chemical Research in Chinese Universities ›› 2015, Vol. 31 ›› Issue (4): 603-610.doi: 10.1007/s40242-015-4469-8

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Influence of Cr on the Electronic Properties of Passive Film on B30 Alloy in NaOH Solution

SHANG Yongbin1, XIAO Shuqin2,3, QIU Xiaolin2,3, WEI Yaming2,3   

  1. 1. Xi'an Changqing Technology & Engineering Co., Ltd., Xi'an 710018, P. R. China;
    2. Oil & Gas Technology Institute, Changqing Oil Field Company, Xi'an 710018, P. R. China;
    3. National Engineering Laboratory for Exploration and Development of Low-permeability Oil & Gas Fields, Xi'an 710018, P. R. China
  • Received:2014-12-05 Revised:2015-04-29 Online:2015-08-01 Published:2015-05-25
  • Contact: SHANG Yongbin E-mail:ctec-syb@cnpc.com.cn
  • Supported by:

    Supported by the Project of Enhanced Oil Recovery of Ground Technology Research of Changqing Oilfield, China (No.2012-E23).

Abstract:

The influence of Cr on the electronic properties of the passive film on B30 alloy in NaOH solution was studied via electrochemical impedance spectra(EIS), potentiodynamic curve and Mott-Schottky plot. The Cr doped in the passive film on B30 alloy was detected by X-ray photoelectron spectroscopy(XPS). XPS results show that Cr2O3 appeared on the passive film, which implied the enhanced anti-corrosion of B30 alloy. The passive film showed a p-type semi-conductive character. The acceptor density(NA) was in an order of magnitude of 1022 cm-3, and NA decreased with the increment of Cr. EIS results show that the film resistance(Rf) increased with increasing the amount of Cr. The diffusion coefficient(D0) was calculated to be in a range of 10-16—10-17 cm-2/s on the basement of point defect model(PDM).

Key words: Electrochemcal impedance spectrum, X-Ray photoelectron spectroscopy, Passive film