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5256 |
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Friday, June 09, 2017, Hall 26 11:00 AM Corrosion Protection |
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In-flight particle temperature and velocity effects on the corrosion resistance of HVOF-sprayed stainless steel coatings in artificial sea water. |
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Alexandre Nascimento* / Concordia University, Canada Fadhel Ben Ettouil / Concordia University, Canada Christian Moreau/ Concordia University, Canada Samantha Gateman/ McGill University, Canada Janine Mauzeroll/ McGill University, Canada Sylvio Savoie/ Institut de Recherche d'Hydro Québec, Canada Robert Lacasse/ Institut de Recherche d'Hydro Québec, Canada Robert Schulz/ Institut de Recherche d'Hydro Québec, Canada |
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This work reports the effects of the spray parameters on the microstructure and corrosion properties of a 444 ferritic stainless steel coating produced by HVOF. The coatings were produced after the establishment of a process map that allowed creating coatings with little overlap in their in-flight temperatures and velocities as determined by the DPV-eVOLUTION diagnostics system. Microstructural investigation revealed that porosity can be reduced by increasing particle velocities. Mass spectroscopy and XRD analysis revealed that oxidation level was highest at spray conditions that favored high velocities and low temperatures. Chemical analysis revealed that the exposure to high temperature causes the loss of alloying elements such as chromium and titanium. The corrosion resistance of the coatings in artificial sea water was measured by potentiodynamic polarization and it was found to be inferior to that of a bulk stainless steel plate. Coatings with less pores and oxides showed lower corrosion currents during the scanning. |