Open AccessComparative study of hot corrosion behavior of thermal sprayed alumina and titanium oxide reinforced alumina coatings on boiler steel
Author(s) -
Gurdeep Singh,
Sunel Kumar,
Raman Kumar
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ab6e7e
Subject(s) - materials science , muffle furnace , corrosion , metallurgy , coating , oxide , molten salt , thermal spraying , titanium , high temperature corrosion , composite material , calcination , chemistry , biochemistry , catalysis
The current work evaluates the effect of hot corrosion on ASTM-SA213-T-22 Steel with a coating of 100Al 2 O 3 and 20TiO 2 -Al 2 O 3 at 900 °C in the molten salt environment of (Na 2 SO 4 -60% V 2 O 5 ). The coatings were sprayed by plasma spray technique. The bare and coated samples were placed inside the muffle furnace at 900 °C for 50 cycles. Each cycle consisted of heating for 1 h and 20 min of cooling at ambient temperature. The kinetics of hot corrosion was analyzed by measuring mass gain after each cycle. The results were achieved by using visual examination, mass change measurement, XRD and SEM/EDS analysis. The result revealed that bare steel was more affected with corrosion and gained more mass due to the development of iron oxide (Fe 2 O 3 ) than the coated sample. Fe 2 O 3 and Cr 2 O 3 were found as major phase in oxide scale of T-22 uncoated steel specimen. The 100Al 2 O 3 and 20TiO 2 -Al 2 O 3 coated specimen indicated the reduction in mass gain by 25.41% and 67.02% respectively as compared to uncoated specimen. Al 2 O 3 coating with the combination of TiO 2 showed better adhesion properties. The presence of TiO 2 enhanced the durability and strength of Al 2 O 3 coating to withstand high temperatures.