Open AccessPreparation and molten salt corrosion behaviors of TiO2/Al2O3/Incone1625 composite coatings on the surface of Q235 alloy at 900 °C
Author(s) -
Tuchun Chen,
Long Bai,
Kunkun Wen
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/631/2/022059
Subject(s) - materials science , corrosion , coating , composite number , molten salt , non blocking i/o , alloy , layer (electronics) , oxide , metallurgy , salt (chemistry) , conversion coating , composite material , chemistry , catalysis , biochemistry
Sol-gel method combined with plasma surfacing was used to prepare TiO 2 /Al 2 O 3 /Incone1625 composite coatings on the surface of Q235 alloys. To investigate the corrosion resistance of this coatings, samples with Incone1625 single coating and TiO 2 /Al 2 O 3 /Incone1625 composite coating were corroded with NaCl and Na 2 SO 4 salts with the weight ration of 1:1at 900 °C in air for 24 h. Molten salt corrosion thermodynamic results show the composite coatings caused lower oxidation weight gain than the sample with single coating. Combination of XRD and SEM results illustrates that the surface and cross-sectional morphology were composed of an outermost loose and cracked NiO and iron oxides layer for the Incone1625 coated sample. For the composite coating sample, the oxide film was composed of more compact NiO and Cr 2 O 3 as the main layer. There were inner oxidation regions for both samples, but region for sample with composite coating was more thinner than that for sample with single coating. This work shows that TiO 2 /Al 2 O 3 /Incone1625 composite coating improves the molten salt corrosion resistance properties of the Q235 alloy at 900 °C by promoting the formation of the protective Cr 2 O 3 film on the sample surface.