Next Article in Journal
Controlled Shrinkage of Expanded Glass Particles in Metal Syntactic Foams
Previous Article in Journal
Wet-Chemical Synthesis of 3D Stacked Thin Film Metal-Oxides for All-Solid-State Li-Ion Batteries
Open AccessArticle

Pitting Initiation and Propagation of X70 Pipeline Steel Exposed to Chloride-Containing Environments

1
Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), University of Science and Technology Beijing, Beijing 100083, China
2
Department of Mechanical Engineering, University of South Florida, Tampa, FL 33620, USA
*
Author to whom correspondence should be addressed.
Materials 2017, 10(9), 1076; https://doi.org/10.3390/ma10091076
Received: 20 July 2017 / Revised: 5 September 2017 / Accepted: 6 September 2017 / Published: 13 September 2017
(This article belongs to the Section Energy Materials)
Inclusion-induced pitting initiation mechanisms in X70 steel were investigated by scanning electron microscopy, scanning Kelvin probe force microscopy (SKPFM), immersion and electrochemical polarization tests in chloride-containing ion solutions. There are three inclusion types in the X70 steel. Corrosion test results indicated that pitting corrosion resistance of type A inclusion < type C inclusion < type B inclusion, i.e., (Mn, Ca)S < matrix < (Al, Ca)O. SKPFM test results show that the type A inclusion exhibited both lower and higher potentials than the matrix, while the type B inclusion exhibited higher potential than the matrix. The corrosion test and the SKPFM potential test results are consistent. Potentiodynamic polarization results indicate that the type A and C are active inclusions, while the type B is an inactive inclusion. Three kinds of possible mechanisms of inclusion-induced pitting corrosion are established for the X70 steel. View Full-Text
Keywords: pitting corrosion; inclusions; SKPFM; X70 pipeline steel pitting corrosion; inclusions; SKPFM; X70 pipeline steel
Show Figures

Figure 1

MDPI and ACS Style

Yang, Z.; Kan, B.; Li, J.; Su, Y.; Qiao, L.; Volinsky, A.A. Pitting Initiation and Propagation of X70 Pipeline Steel Exposed to Chloride-Containing Environments. Materials 2017, 10, 1076.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop