Effect of phosphating time on protection properties of hurealite coating: Differences between ground and shot peened HSLA steel surface

0508085 - ÚFM 2020 RIV CH eng J - Journal Article
Hadzima, B. - Pastorek, F. - Borko, K. - Fintová, Stanislava - Kajánek, D. - Bagherifard, S. - Gholami-Kermanshahi, G. - Trško, L. - Pastorková, J. - Brezina, J.
Effect of phosphating time on protection properties of hurealite coating: Differences between ground and shot peened HSLA steel surface.
Surface and Coatings Technology. Roč. 375, OCT (2019), s. 608-620. ISSN 0257-8972
R&D Projects: GA MŠMT(CZ) EF16_013/0001823
Institutional support: RVO:68081723
Keywords : surface treatment * phosphating * HSLA steel * electrochemical impedance spectroscopy * shot peening
OECD category: Coating and films
Impact factor: 3.784, year: 2019
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0257897219307960

Shot peening is a standard surface treatment primarily used for enhancement of fatigue properties of metallic
materials. However, its influence on surface properties is so radical, that subsequent techniques of surface
treatment used on the shot peened surface need to be reconsidered in order to minimize the possible negative
side effects of shot peening. In this case, the differences between hurealite formation on the ground and shot
peened surfaces of modern high strength low alloy (HSLA) steel were evaluated by morphological and electrochemical
corrosion observations and measurements. The surface morphologies of the formed coatings were
observed by the scanning electron microscopy (SEM) and analysed by energy-dispersive X-ray analysis (EDX).
The corrosion resistance of the HSLA steel with hurealite coating was evaluated using electrochemical impedance
spectroscopy (EIS) by the analysis of Nyquist plots obtained in 0.1M NaCl solution after various
phosphating times on both types of pre-treated surfaces (ground and shot peened). The results showed that used
technique of shot peening negatively influenced the phosphating process by prolonging the phosphating process
in order to reach the coating with maximal protection properties in tested medium. Moreover, shot peened
surface caused significantly enlarged size of the hurealite crystals and greater thickness of the coating compared
to the surface pre-treated by grinding on the tested HSLA steel at the expense of a lower compactness and
corrosion protection.

Permanent Link: http://hdl.handle.net/11104/0299691