Lietuvos mokslų akademijos Leidybos skyrius
    Tel. +370 5 2626851, +370 5 2613620 El. paštas leidyba@lma.lt
Chemija / Chemistry

ISSN 0235-7216
ISSN 2424-4538 (online)

2015 m. Nr. 3

The self-healing ability of cerium oxide films on carbon steel
O. GIRČIENĖ, L. GUDAVIČIŪTĖ, A. SELSKIS, V. JASULAITIENĖ, S. ŠAKIRZANOVAS, R. RAMANAUSKAS

Active corrosion protection of metals implies not only mechanical covering of the protected surface with a dense barrier coating, but also provides self-healing properties, which allow durable protection even after partial damage of the coating. The aim of the present study was to develop the deposition process of a chrome-free conversion coating on carbon steel and to study its self-healing capacities. The amorphous phosphate coating on carbon steel was chosen as the base for deposition of the cerium oxide films. The SEM, XRD and XPS techniques were applied for the structural, phase and composition characterization of the investigated coatings, voltametric measurements were carried out to determine the passive layer protective ability, while EIS studies yielded information on the self-healing properties of different protective systems affected by introduced artificial defects. The carbon steel and the phosphated carbon steel surfaces were modified with Ce ions by deposition of Ce films from the Ce(NO3)3 solution without and with SO4 2– ions. The presence of the SO4 2– ions in the conversion solution resulted in formation of the film, containing a larger amount of Ce, with respect to the pure Ce(NO3)3 solution and a higher amount of Ce4+ in the film. However, a low conversion films thickness and the presence of cracks yielded a lower level of steel corrosion protection. The increase of the low frequency impedance during immersion of the samples with a cerium film can be correlated to the active corrosion protection originating the self-healing of defects.

Keywords: carbon steel, phosphate coating, cerium oxide film, self-healing

Issues:

2017 - Vol.28
No. 1, No. 2, No. 3, No. 4

2016 - Vol.27
No. 1, No. 2, No. 3, No. 4

2015 - Vol.26
No. 1, No. 2, No. 3, No. 4

2014 - Vol.25
No. 1, No. 2, No. 3, No. 4

2013 - Vol.24
No. 1, No. 2, No. 3, No. 4

2012 - Vol.23
No. 1, No. 2, No. 3, No. 4

2011 - Vol.22
No. 1, No. 2, No. 3, No. 4

2010 - Vol.21
No. 1, No. 2-4

2009 - Vol.20
No. 1, No. 2, No. 3, No. 4

2008 - Vol.19
No. 1, No. 2, No. 3-4

2007 - Vol.18
No. 1, No. 2, No. 3, No. 4

2006 - Vol.17
No. 1, No. 2-3, No. 4

2005 - Vol.16
No. 1, No. 2, No. 3-4

2004 - Vol.15
No. 1, No. 2, No. 3, No. 4

2003 - Vol.14
No. 1, No. 2, No. 3, No. 4

2002 - Vol.13
No. 1, No. 2, No. 3, No. 4

2001 - Vol.12
No. 1, No. 2, No. 3, No. 4