Effect of ceria coating on corrosion behaviour of low alloy steel

Ceria films were deposited by electroless method on a nickel-based superalloy, Superni 75, to improve its performance at high temperatures. Ceria was produced from cerium acetate using triethanolamine as the reducing agent. The films were produced at three concentrations -0.1, 0.2 and 0.3 M of cerium acetate, to study the effect of increasing cerium concentration. For comparative study, the coated and bare substrates were oxidized at 1173 K for 100 h in air. The morphology and the chemistry of the oxide scale formed were analysed using FEG-SEM/EDS and XRD. It has been observed that increasing the cerium concentration in the film increases the oxidation resistance of the substrate which is evident from the calculated parabolic rate constant. It was also observed that the morphology of the scale improves with the increase in the concentration of cerium in the film. The scale formed on the ceria-coated substrate at 0.3 M concentration is dense and more uniform.

Section: Introductionmentioning

confidence: 99%

Electroless nanoceria films on nickel-based superalloy

Lone

Rahman

2019

“…The properties like porosities, cracking and residual stress on the microstructure can affect the high temperature oxidation and corrosion properties [8][9][10][11]. The different plasma sprayed ceramic oxide coating employed for oxidation/corrosion resistance has been reported by many researchers [12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Oxidation behaviour of nanostructured YSZ plasma sprayed coated Inconel alloy

Ghosh

Das

Roy

et al. 2018

This paper investigates the effect of nanostructured and micrometre size YSZ powder coated plasma spray coating on high temperature oxidation resistance of Inconel (IN 718) substrate. The oxidation rate and reaction kinetics are studied, and the post-corroded scales are characterised in SEM, field emission SEM and X-ray diffraction. The results clearly indicate that there is an improvement of oxidation resistance in the case of nanostructured YSZ coating as compared to the micrometre size YSZ coated specimen. The detail mechanism of the significant improvement of the oxidation resistance of nanostructured coating is discussed in this paper.

“…1 The additions of Ce, Y, Zr, La (rare earth elements) or their oxides improve the high temperature oxidation resistance in chromia and alumina forming alloys due to a decrease in scale growth rate and improved resistance to scale spallation by improving the scale-alloy adhesion. [4][5][6][7][8] The improvement of oxidation resistance of nanocrystalline CeO 2 coated alloys over the microsize CeO 2 coated alloys has been reported in the past by several researchers. 9,10 Ghosh et al 9 have reported the tremendous improvement of oxidation resistance of nanocrystalline CeO 2 coated SS-304 stainless steel over micrometre size CeO 2 coated alloys.…”

Section: Introductionmentioning

confidence: 99%

Nanostructured CeO₂ coating for high temperature oxidation protection

Ghosh

Roy

Das

et al. 2016

This paper investigates the influence of nanostructured ceria (CeO 2 ) coating on high temperature oxidation behaviour of 2?25 Cr-1 Mo steel. The isothermal corrosion study of the micrometre size and nanostructured CeO 2 coated specimens was conducted in air oxidation environment at 973 K for 8 h. The corrosion rate and reaction kinetics were studied, and the post-corroded scales were characterised by field emission scanning electron microscopy and X-ray diffraction. The results clearly indicate that the nanostructured CeO 2 coated specimen improves the oxidation resistance than does the micrometre size CeO 2 coated specimen. The improvement of oxidation resistance in the case of nanostructured CeO 2 can be attributed to the formation of semimolten zone, which consists of nanostructured CeO 2 particle. On the other hand, in the absence of semimolten nanostructured zone, the micrometre size powder coated specimen shows higher corrosion rate in comparison to the nanosize CeO 2 powder coated specimen.